Gap Analysis in Internet Addressing
draft-jia-intarea-internet-addressing-gap-analysis-00
The information below is for an old version of the document.
| Document | Type |
This is an older version of an Internet-Draft whose latest revision state is "Replaced".
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|---|---|---|---|
| Authors | Yihao Jia , Dirk Trossen , Luigi Iannone , Nirmala Shenoy , Paulo Mendes | ||
| Last updated | 2021-07-12 | ||
| Replaced by | draft-iannone-internet-addressing-considerations | ||
| RFC stream | (None) | ||
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| Consensus boilerplate | Unknown | ||
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draft-jia-intarea-internet-addressing-gap-analysis-00
Internet Area Working Group Y. Jia
Internet-Draft D. Trossen
Intended status: Informational L. Iannone
Expires: January 13, 2022 Huawei
N. Shenoy
R.I.T.
P. Mendes
Airbus
July 12, 2021
Gap Analysis in Internet Addressing
draft-jia-intarea-internet-addressing-gap-analysis-00
Abstract
There exist many extensions to Internet addressing, as it is defined
in [RFC0791] for IPv4 and [RFC8200] for IPv6, respectively. Those
extensions have been developed to fill gaps in capabilities beyond
the basic properties of Internet addressing. This document outlines
those properties as a baseline against which the extensions are
categorized in terms of methodology used to fill the gap together
with examples of solutions doing so.
While introducing such extensions, we outline the issues we see with
those extensions. This ultimately leads to consider whether or not a
more consistent approach to tackling the identified gaps, beyond
point-wise extensions as done so far, would be beneficial. The
benefits are the ones detailed in the companion document
[I-D.jia-intarea-scenarios-problems-addressing], where, leveraging on
the gaps identified in this memo and scenarios provided in
[I-D.jia-intarea-scenarios-problems-addressing], a clear problem
statement is provided.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
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Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
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This Internet-Draft will expire on January 13, 2022.
Copyright Notice
Copyright (c) 2021 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of
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described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Properties of Internet Addressing . . . . . . . . . . . . . . 3
2.1. Property 1: Fixed Address Length . . . . . . . . . . . . 4
2.2. Property 2: Ambiguous Address Semantic . . . . . . . . . 4
2.3. Property 3: Limited Address Semantic Support . . . . . . 4
3. Filling Gaps through Extensions to Internet Addressing
Properties . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.1. Length Extensions . . . . . . . . . . . . . . . . . . . . 5
3.1.1. Shorter Address Length . . . . . . . . . . . . . . . 5
3.1.2. Longer Address Length . . . . . . . . . . . . . . . . 7
3.1.3. Summary . . . . . . . . . . . . . . . . . . . . . . . 8
3.2. Identity Extensions . . . . . . . . . . . . . . . . . . . 8
3.2.1. Anonymous Address Identity . . . . . . . . . . . . . 9
3.2.2. Authenticated Address Identity . . . . . . . . . . . 12
3.2.3. Summary . . . . . . . . . . . . . . . . . . . . . . . 13
3.3. Semantic Extensions . . . . . . . . . . . . . . . . . . . 14
3.3.1. Utilizing Extended Address Semantics . . . . . . . . 14
3.3.2. Utilizing Existing or Extended Header Semantics . . . 17
3.3.3. Summary . . . . . . . . . . . . . . . . . . . . . . . 20
4. Overview of Approaches to Extend Internet Addressing . . . . 21
5. Issues in Extensions to Internet Addressing . . . . . . . . . 22
5.1. Limiting Address Semantics . . . . . . . . . . . . . . . 22
5.2. Complexity and Efficiency . . . . . . . . . . . . . . . . 22
5.2.1. Repetitive encapsulation . . . . . . . . . . . . . . 23
5.2.2. Compounding issues with header compression . . . . . 24
5.2.3. Introducing Path Stretch . . . . . . . . . . . . . . 24
5.2.4. Complicating Traffic Engineering . . . . . . . . . . 24
5.3. Security . . . . . . . . . . . . . . . . . . . . . . . . 25
5.4. Fragility . . . . . . . . . . . . . . . . . . . . . . . . 25
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6. Summary of issues in Extensions to Internet Addressing . . . 26
7. Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . 28
8. Security Considerations . . . . . . . . . . . . . . . . . . . 29
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 30
10. Informative References . . . . . . . . . . . . . . . . . . . 30
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 38
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 38
1. Introduction
[I-D.jia-intarea-scenarios-problems-addressing] outlines scenarios
and problems in Internet addressing through presenting a number of
cases of communication that have emerged over the many years of
utilizing the Internet and for which various extensions to the
network interface-centric addressing of IPv6 have been developed. In
order to continue the discussion on the emerging needs for
addressing, initiated with
[I-D.jia-intarea-scenarios-problems-addressing], this memo aims at
identifying gaps between the Internet addressing model and desirable
features that have been added by various extensions, in various
contexts.
Our approach to identifying the gaps is guided by key properties of
Internet addressing, outlined in Section 2, namely (i) the fixed
length of the IP addresses, (ii) the ambiguity of IP addresses
semantic, while still (iii) providing limited IP address semantic
support only. We derive those properties directly as a consequence
of the respective standards that provide the basis for Internet
addressing, most notably [RFC0791] for IPv4 and [RFC8200] for IPv6,
respectively.
Those basic properties, and the potential issues that arise from
those properties, give way to extensions that have been proposed over
the course of deploying new Internet technologies. Section 3
discusses those extensions, summarized as gaps against the basic
properties in Section 4.
Finally, we outline issues that arise with the extension-driven
approach to the basic Internet addressing, discussed in Section 5.
We argue that any requirements for solutions that would revise the
basic Internet addressing would require to address those issues.
2. Properties of Internet Addressing
As the Internet Protocol adoption has grown towards the global
communication system we know today, its characteristics have evolved
subtly, with [RFC6250] documenting various aspects of the IP service
model and its frequent misconceptions, including Internet addressing.
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In this section, we articulate the three most acknowledged properties
related to _Internet addressing_. Those are (i) fixed IP address
length, (ii) ambiguous IP address semantic, and (iii) limited IP
address semantic support.
In Section 3, we elaborate on various extensions that aim to expand
Internet addressing beyond those properties; we position those
extensions as intentions to close perceived gaps against those key
properties.
2.1. Property 1: Fixed Address Length
The fixed IP address length is specified as a key property of the
design of Internet addressing, with 32 bits for IPv4 ([RFC0791]), and
128 bits for IPv6 ([RFC8200]), respectively. Given the capability of
the hardware at the time of IPv4 design, a fixed length address was
considered as a more appropriate choice for efficient packet
forwarding. Although the address length was once considered to be
variable during the design of Internet Protocol Next Generation
("IPng", cf., [RFC1752]) in 1990s, it finally inherited the design of
IPv4 and adopted a fixed length address towards the current IPv6. As
a consequence, the 128-bit fixed address length of IPv6 is regarded
as a balance between fast forwarding (i.e., fixed length) and
practically boundless cyberspace (128-bit length).
2.2. Property 2: Ambiguous Address Semantic
Initially, the meaning of an IP address has been to identify an
interface on a network device, although, when [RFC0791] was written,
there were no explicit definitions of the IP address semantic.
With the global expansion of the Internet protocol, the semantic of
the IP address is commonly believed to contain at least two notions,
i.e., the explicit "locator", and the implicit "identifier". Because
of the increasing use of IP addresses to both identify a node and to
indicate the physical or virtual location of the node, the
intertwined address semantics of identifier and locator was then
gradually observed and first documented in [RFC2101] as "locator/
identifier overload" property. With this, the IP address is used as
an identification for host and server, very often directly used,
e.g., for remote access or maintenance.
2.3. Property 3: Limited Address Semantic Support
Although IPv4 [RFC0791] did not add any semantic to IP addresses
beyond interface identification (and location), time has proven that
additional semantics are desirable (c.f., the history of 127/8
[HISTORY127] or the introduction of private addresses [RFC1918]),
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hence, IPv6 [RFC4291] introduced some form of additional semantics
based on specific prefix values, for instance link-local addresses or
a more structured multicast addressing. Nevertheless, systematic
support for rich address semantics remains limited and basically
prefix-based.
3. Filling Gaps through Extensions to Internet Addressing Properties
Over the years, a plethora of extensions has been proposed in order
to move beyond the native properties of IP addresses. We interpret
the development of those extensions as filling gaps between the
original properties of Internet addressing, outlined in the previous
section, and desired new capabilities that those developing the
extensions identified as being needed and desirable.
3.1. Length Extensions
Extensions in this subsection aim at extending the property described
in Section 2.1, i.e., fixed IP address length.
When IPv6 was designed, the main objective was to create an address
space that would not lead to the same situation as IPv4, namely to
address exhaustion. To this end, while keeping the same addressing
model like IPv4, IPv6 adopted a 128-bit address length with the aim
of providing a sufficient and future-proof address space. The choice
was also founded on the assumption that advances in hardware and
Moore's law would still allow to make routing and forwarding faster,
and IPv6 routing table manageable.
We observe, however, that the rise of new use cases but also the
number of new, e.g., industrial/home or small footprint devices, was
possibly unforeseen. Sensor networks and more generally the Internet
of Things (IoT) emerged after the core body of work in IPv6.
Nevertheless, it was clear from the beginning that differently from
IPv6 assumptions, 128-bit addresses were costly in certain scenarios.
At the same time, new use cases emerged, where addresses even bigger
than 128-bit are useful, like in the context of content centric
networks, structured addresses, or cryptographically generated
addresses.
3.1.1. Shorter Address Length
3.1.1.1. Description:
In the context of IoT [RFC7228], where bandwidth and energy are very
scarce resources, the static length of 128-bit for an IP address is
more a hindrance than a benefit since 128-bit for an IP address may
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occupy a lot of space, even to the point of being the dominant part
of a packet. In order to use bandwidth more efficiently and use less
energy in end-to-end communication, solutions have been proposed that
allow for very small network layer headers instead.
3.1.1.2. Methodology:
*Header Compression/Translation*: One of the main approaches to
reduce header size in the IoT context is by header compression. Such
technique is based on a stateful approach, utilizing what is usually
called a "context" on the IoT sensor and the gateway for
communications between an IoT device and a server placed somewhere in
the Internet - from the edge to the cloud.
The role of the "context" is to provide a way to "compress" the
original IP header in a smaller one, by using shorter address
information and/or dropping some field, using the context as a kind
of dictionary.
*Separate device from locator identifier*: Approaches that can offer
customized address length that is adequate for use in such
constrained domains are preferred. Using different namespaces for
the 'device identifier' and the 'routing' or 'locator identifier' is
one such approach.
3.1.1.3. Examples
*Header Compression/Translation*: Considering one base station is
supposed to serve hundreds of user devices, maximizing the
effectiveness for specific spectrum directly improve user quality of
experience. To achieve the optimal utilization of the spectrum
resource in wireless area, the RObust Header Compression (ROHC)
[RFC5795] mechanism, which has been widely adopted in cellar network
like WCDMA, LTE, and 5G, utilizes header compression to shrink
existing IPv6 headers onto shorter ones.
Similarly, header compression techniques for IPv6 over Low-Power
Wireless Personal Area Networks (6LoWPAN) have been around for
several years now, constituting a main example of using the notion of
a shared context in order to reduce the size of the network layer
header ([RFC6282], [RFC7400], [ITU9959]). More recently, other
compression solution have been proposed for Low Power Wide Area
Networks (LPWAN - [RFC8376]), but they basically rely on the same
"context" approach ([RFC8724]).
Also, constraints coming from either devices or carrier links would
lead to mixed scenarios and compound requirements for extraordinary
header compression. For native IPv6 communications on DECT ULE and
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MS/TP Networks [RFC6282], dedicated compression mechanisms are
specified in [RFC8105] and [RFC8163], while the transmission of IPv6
packets over NFC and PLC, specifications are being developed in
[I-D.ietf-6lo-nfc] and [I-D.ietf-6lo-plc].
*Separate device from locator identifier*: Solutions such as proposed
in [EIBP] and [I-D.ietf-lisp-rfc6830bis] can utilize a separation of
device from locator, where only the latter is used for routing
between the different domains using the same technology, therefore
enabling the use of shorter addresses in the (possibly constrained)
local environment. Device IDs used within such domains are carried
as part of the payload by EIBP and hence can be of shorter size
suited to the domain, while, for instance, in LISP a flexible address
encoding [RFC8060] allows shorter addresses to be supported in the
LISP control plane [I-D.ietf-lisp-rfc6833bis].
3.1.2. Longer Address Length
3.1.2.1. Description
To address current networking demands it may be preferred to use
variable and longer address lengths. For example in content delivery
networks, longer addresses such as URLs are required to fetch
content, an approach that information-centric networking (ICN)
applied for any data packet sent in the network, using information-
based addressing. Further, as an approach to address the routing
challenges faced in the Internet, structured addresses may be used,
avoiding the need for routing protocols.
Further, as an approach to address the routing challenges such as
scalability, stability and the complex interworking between OSPF,
eBGP and iBGP faced in the Internet, structured addresses may be
used, avoiding the need for routing protocols overall.
3.1.2.2. Methodology
The crucial need for longer address lengths comes from _semantic
extensions_ to IP addresses, where the extensions themselves do not
fit within the length limitation of the IP address. Section 3.3
discusses those extensions, divided into those where limitations
stemming from the IP address lengths are considered and those where
information is either represented through a longer address and/or
additional header information.
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3.1.2.3. Examples
See Section 3.3 for examples of solutions that consider extended
address and header information to represent extended semantics that
are not limited by the IP address length.
3.1.3. Summary
Table 1, summarize the methodologies and the examples towards filling
the gaps on length extensions.
+-----------------+-------------------------------+-----------------+
| | Methodology | Examples |
+-----------------+-------------------------------+-----------------+
| Shorter Address | Header | 6LoWPAN, ROHC |
| Length | compression/translation | |
| | | |
| | Separate device from locator | EIBP, LISP, |
| | identifier | ILNP, HIP |
| | | |
| Longer Address | Same as Semantic Extension | / |
| Length | Table 3 | |
+-----------------+-------------------------------+-----------------+
Table 1: Summary Length Extensions
3.2. Identity Extensions
Extensions in this subsection try extending the property described in
Section 2.2, i.e., "locator/identifier overload" of the ambiguous
address semantic.
From the perspective of Internet users, on the one hand, the implicit
identifier semantic result in the privacy issue of network behavior
tracking and association. Despite that IP address assignment may be
dynamic, they are nowadays considered as a personal data and as such
undergoes privacy protection regulations like General Data Protection
Regulation ("GDPR", cf. [GDPR]). Hence, additional mechanism are
necessary in order to protect end user privacy.
For network regulation of sensitive information, on the other hand,
dynamically allocated IP addresses are not sufficient to guarantee
device or user identification. As such, different address allocation
systems, with stronger identification properties are necessary where
security and authentication are at highest priority. Hence, in order
to protect information security within a network, additional
mechanism are necessary to identify the users or the devices attached
to the network.
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3.2.1. Anonymous Address Identity
3.2.1.1. Description
As discussed in Section 2.2, IP addresses reveal both 'network
locations' as well as implicit 'identifier' information to both
traversed network elements and destination nodes alike. This enables
recording, correlation, and profiling of user behaviors and
historical network traces, possibly down to individual real user
identity. The IETF, e.g., in [RFC7258], has taken a clear stand on
preventing any such pervasive monitoring means by classifying them as
an attack on end users' right to be left along (i.e., privacy).
Regulations such as the EU's General Data Protection Regulation
(GDPR) classifies, for instance, the 'online identifier' as personal
data which must be carefully protected; this includes end users' IP
addresses [GDPR].
Even before pervasive monitoring [RFC7258], IP addresses have been
seen as something that some organizational owners of networked system
may not want to reveal at the individual level towards any non-member
of the same organization.
3.2.1.2. Methodology:
*Traffic Proxy*: Detouring the traffic to a trusted proxy is a
heuristic solution. Since nodes between trusted proxy and
destination (including the destination per se) can only observe the
source address of the proxy, the "identification" of the origin
source can thereby be hidden. To confuse the nodes between origin
and the proxy, the traffic on such route would be encrypted via a key
negotiated either in-band or off-band. Considering that all
applications' traffic in such route can be seen as a unique flow
directed to the same "unknown" node, i.e., the trusted proxy,
eavesdroppers in such route have to make more efforts to correlate
user behavior through statistical analysis even if they are capable
of identifying the users via their source addresses. The protection
lays in the inability to isolate single application specific flows.
According to the methodology, such approach is IP version independent
and works for both IPv4 and IPv6.
*Source Address Rollover*: Privacy issues related to address
"identifier" semantic can be mitigated through regular change (beyond
the typical 24 hours lease of DHCP). Built on the inevitabilities of
"identifier" that IP address carries, such approach promote to change
the source IP address at certain frequency. Under such methodology,
refresh cycling window may reach to a balance between privacy
protection and address update cost. Due to the limited space that
IPv4 contains, such approach usually works for IPv6 only.
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*Private Address Spaces*: Their introduction in [RFC1918] foresaw
private addresses (assigned to specific address spaces by the IANA)
as a means to communicate purely locally, e.g., within an enterprise,
by separating private from public IP addresses. Considering that
private addresses are never directly reachable from the Internet,
hosts adopting private addresses are invisible and thus "anonymous"
for the Internet. Besides, hosts for purely local communication used
the latter while hosts requiring public Internet service access would
still use public IP addresses.
*Address Translation*: The aforementioned original intention for
using private IP addresses, namely for purely local communication,
resulted in a lack of flexibility in changing from local to public
Internet access on the basis of what application would require which
type of service.
If eventually every end-system in an organization would require some
form of public Internet access in addition to local one, an adequate
number of public Internet addresses would be required for providing
to all end systems. Instead, address translation enables to utilize
many private IP addresses within an organization, while only relying
on one (or few) public IP addresses for the overall organization.
In principle, address translation can be applied recursively. This
can be seen in modern broadband access where Internet providers may
rely on carrier-grade address translation for all their broadband
customers, who in turn employ address translation of their internal
home or office addresses to those (private again) IP addresses
assigned to them by their network provider.
Two benefits arise from the use of (private to public IP) address
translation, namely (i) the hiding of local end systems at the level
of the (address) assigned organization, and (ii) the reduction of
public IP addresses necessary for communication across the Internet.
While the latter has been seen for long as a driver for address
translation, we focus on the first issue in this section, also since
we see such privacy benefit as well as objective as still being valid
in addressing systems like IPv6 where address scarcity is all but
gone [GNATCATCHER].
*Separate device from locator identifier*: Solutions that make a
clear separation between the routing locator and the identifier, can
allow for a device ID of any size, which in turn can be encrypted by
a network element deployed at the border of routing domain (e.g., a
router). Both source and end domain addresses can be encrypted and
transported, as in the routing domain, only the routing locator is
used.
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3.2.1.3. Examples:
*Traffic Proxy*: Although not initially designed for traffic proxy,
Virtual Private Network (VPN, cf. [VPN]) is widely utilized for
packets origin hiding as a traffic detouring methodology. As it
evolved, VPN derivatives like WireGuard [WireGuard] become a
mainstream instance for user privacy and security enhancement.
With such methodology in mind, onion routing [ONION], instantiated in
the TOR Project [TOR], achieves high anonymity through traffic hand
over via intermediates before reaching the destination. Since the
architecture of TOR requires at least three proxies in traffic, none
of them is aware of the entire route. Given that the proxies
themselves can be deployed all over the cyberspace, trust will not be
the prerequisite if proxies are randomly selected.
In addition, dedicated protocols are also expected to be customized
for privacy improvement via traffic proxy. For example, Oblivious
DNS over HTTPS (ODoH, cf. [ODoH]) use a third-part proxy to obscure
identifications of user source addresses during DNS over HTTPS (DoH,
cf. [RFC8484]) resolution. Similarly, Oblivious HTTP [OHTTP] involve
proxy alike in the HTTP environment.
*Source Address Rollover*: As for source address rollover, it has
been standardized that IP addresses for Internet users should be
dynamic and temporary every time they are being generated [RFC8981].
This benefits from the available address space in the case of IPv6,
through which address generation or assignment should be
unpredictable and stochastic for outside observers.
More radically, [EPHEMERALv6] advocates an 'ephemeral address' for
each process that change over time. Through this, correlating user
behaviors conducted by different identifiers (i.e., source address)
becomes hard, if not impossible, based on the IP packet header alone.
*Private Addresses*: The use and assignment of private address for
IPv4 is laid out in [RFC1918], while unique local addresses (ULAs) in
IPv6 [RFC4193] take over the role of private address spaces in IPv4.
*Network Address Translation*: The translation from one IP address
realm into another is laid out in [RFC2663], using a stateful address
binding to translate between the realms, e.g., from a private into a
public address space. As outlined in [RFC2663], basic address
translation is usually extended to include port information in the
translation process, support bidirectional or simple outbound traffic
only. Given address translation can be performed several times in
cascade, NATs may exist as part of existing customer premise
equipment (CPE), such as a cable or an Ethernet router, with private
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wired/wireless connectivity, or may be provided in a carrier
environment to further translate ISP-internal private addresses to a
pool of (assigned) public IP addresses. The latter is often
dynamically assigned to CPEs upon bootstrapping of the CPE.
*Separate device from locator identifier*: EIBP [EIBP] utilizes a
structured approach to addressing. It separates the routing ID from
the device ID, where only the routing ID is used for routing. Hence
the device IDs can be encrypted. Similarly, LISP uses separate
namespaces for routing and identification allowing to "hide"
identifiers in encrypted LISP packets that expose only known routing
information [RFC8061].
3.2.2. Authenticated Address Identity
3.2.2.1. Description
In some scenarios (e.g., corporate networks) it desirable to being
able authenticate IP addresses so to prevent malicious attackers to
spoof IP addresses. This is usually achieved by using a mechanism
that allows to prove ownership of the IP address.
3.2.2.2. Methodology
*Self-certified addresses*: This method is usually based on the use
of nodes' public/private keys. A node creates its own interface ID
(IID) by using a cryptographic hash of its public key (with some
additional parameters). Messages are then signed using the nodes'
private key. The destination of the message will verify the
signature through the information in the IP address. Self-
certification has the advantage that no third party or additional
security infrastructure is needed. Any node can generate its own
address locally and then only the address and the public key are
needed to verify the binding between the public key and the address.
*Third party granted addresses*: DHCP (Dynamic Host Configuration
Protocol) is widely used to provide IP addresses, however, in its
basic form, it does not perform any check and even an unauthorized
user without the right to use the network can obtain an IP address.
To solve this problem, a trusted third party has to grant access to
the network before generating an address (via DHCP or other) that
identifies the user. User authentication done securely either based
on physical parameters like MAC addresses or based on an explicit
login/password mechanism.
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3.2.2.3. Examples
*Self-certified Addresses*: Major example of this methodology is
[RFC3972], where IPv6 cryptographically Generated Addresses (CGA) are
defined. The original specs have been already amended (cf.,
[RFC4581] and [RFC4982]) in order to support multiple (stronger)
cryptographic algorithms.
*Third party granted addresses*: [RFC3118] defines a DHCP option
through which authorization tickets can be generated and newly
attached hosts with proper authorization can be automatically
configured from an authenticated DHCP server. Solutions exists where
separate servers are used for user authentication ([UA-DHCP],
[RFC4014])
3.2.3. Summary
Table 2, summarize the methodologies and the examples towards filling
the gaps on identity extensions.
+------------------------+----------------------------+-------------+
| | Methodology | Examples |
+------------------------+----------------------------+-------------+
| Anonymous Address | Traffic Proxy | VPN, TOR, |
| Identity | | ODoH |
| | | |
| | Source Address Rollover | SLAAC |
| | | |
| | Private Address Spaces | ULA |
| | | |
| | Address Translation | NAT |
| | | |
| | Separate device from | EIBP, LISP |
| | locator identifier | |
| | | |
| Authenticated Address | Self-certified Addresses | CGA |
| Identity | | |
| | | |
| | Third party granted | DHCP-Option |
| | addresses | |
+------------------------+----------------------------+-------------+
Table 2: Summary Identity Extensions
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3.3. Semantic Extensions
Extensions in this subsection try extending the property described in
Section 2.3, i.e., limited address semantic support.
As explained in Section 2.2, IP addresses carry both locator and
interface identification semantic. Some efforts exists in trying to
separate these semantics either in different address spaces or
through different address format. Beyond just identification,
location, and the fixed address size, other efforts extended the
semantic through existing or additional header fields (or header
options) outside the Internet address.
3.3.1. Utilizing Extended Address Semantics
3.3.1.1. Description
Several extensions have been developed to extend beyond the limited
IPv6 semantics. Those approaches may include to apply structure to
the address, utilize specific prefixes or entirely utilize the IPv6
address for different semantics while re-encapsulating the original
packet to restore the semantics in another part of the network. For
instance, structured addresses have the capability to introduce
delimiters to identify semantic information in the header, therefore
not constraining any semantic by size limitations of the address
fields. We note here that extensions often start out as being
proposed as an extended header semantic, while standardization may
drive the solution to adopt an approach to accommodate their semantic
within the limitations of an IP address. This section does include
examples of this kind.
3.3.1.2. Methodology
*Semantic prefixes*: Semantic prefixes are used to separate the IPv6
address space. Through this, new address families, such as for
information-centric networking [HICN], service routing or other
semantically rich addressing, can be defined, albeit limited by the
prefix length and structure as well as the overall length limitation
of the IPv6 address.
*Separate device from locator identifier*: The option to use separate
namespaces for the device address (w.r.t. the router locator), would
offer more freedom for the use of different semantics.
*Structured addressing*: One approach to address the routing
challenges faced in the internet proposes the use of structured
addresses, to void the need for routing protocols. Benefits of this
approach can be significant, with the structured addresses capturing
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the relative physical or virtual position of routers in the network,
and being variable in length. Key to the approach, however, is that
the structured addresses capturing the relative physical or virtual
position of routers in the network, or networks in an internetwork
may not fit within the fixed and limited IP address length (cf.,
Section 3.1.2). Other approaches to structured approaches may be the
definition of application-specific structured binary components as a
generalization of the URL schema used for HTTP-level communication.
*Localized forwarding semantics*: Layer 2 hardware, such as SDN
switches, are limited to the use of specific header fields for
forwarding decisions. Hence, devising new localized forwarding
mechanisms may make use of existing header fields such as the IPv6
source/destination field to achieve the desired forwarding behavior,
while encapsulating the original IPv6 packets into the payload in
order to be restored at the local forwarding network boundary.
Network sizes in those solutions are limited by the size of the
utilized address field, e.g., 256 bits for IPv6, thereby limiting the
size of networks where such techniques could be used. The IPv6
address information provided in the encapsulated packet purely serves
identifying the network endpoint, not its location.
3.3.1.3. Examples
*Semantic prefixes*: Newer approaches to IP anycast suggest the use
of service identification in combination with a binding IP address
model [SFCANYCAST] as a way to allow for metric-based traffic
steering decisions; approaches for Service Function Chaining (SFC)
[RFC7665] utilize the next service header (NSH) information and
packet classification to determine the destination of the next packet
hop.
Another example of the usage of different packet header extensions
based in IP addressing is Segment Routing. In this case the source
chooses a path and encodes it in the packet header as an ordered list
of segments. Segments are coded at header of IPv6 Packet, based on
the definition of a new Routing Extensions Header type, the Segment
Routing Header (SRH), which contains Segment List. This is similar
to what is already specified in RFC2460. Packets are then
transmitted from source node with a list of segment ID (SID) inserted
at header List dictates the path to follow in the network. Such
segment ID are coded as 128 bit IPv6 addresses.
Approaches such as [HICN] utilize semantic prefixing to allow for ICN
forwarding behavior within an IPv6 network. In this case an HICN
name is the hierarchical concatenation of a name prefix and a name
suffix, in which the name prefix is encoded as an IPv6 128 bits word
and carried in IPv6 header fields, while the name suffix is encoded
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in transport headers fields such as TCP. However, it is a challenge
to determine which IPv6 prefixes should be used as name prefixes. In
order to know which IPv6 packets should be interpreted based on an
ICN semantic, it is desirable to be able to recognize that an IPv6
prefix is a name prefix, e.g. to define a specific address family
(AF_HICN, b0001::/16). This establishment of a specific address
family allows the management and control plane to locally configure
HICN prefixes and announce them to neighbors for interconnection.
*Separate device from locator identifier*: EIBP [EIBP] separates the
routing locator from the device identifier, relaxing therefore any
semantic constraints on the device identifier. Similarly, LISP uses
a flexible encoding named LISP Canonical Address Format (LCAF
[RFC8061]), which allows to associate to routing locators any
possible form (and length) of identifier. ILNP [RFC6740] introduces
as well a different semantic of IP addresses, while aligning to the
IPv6 address format (128 bits). Basically, ILNP introduces a sharper
logical separation between the 64 most significant bits and the 64
least significant bits of an IPv6 address. The former being a global
locator, while the latter being an identifier that can have different
semantic (rather than just being an interface identifier).
*Structured addressing*: Network topology captures the physical
connectivity among devices in the network. There is a structure
associated with the topology. Examples are the core-distribution-
access router structure commonly used in enterprise networks and clos
topologies that are used to provide multiple connections between Top
of Rack (ToR) devices and multiple layers of spine devices. Internet
service providers use a tier structure that defines their business
relationships. A clear structure of connected networks can be
noticed in the internet. EIBP [EIBP] proposes to leverage the
physical structure (or a virtual structure overlaid on the physical
structure) to auto assign addresses to routers in a network or
networks in an internetwork to capture their relative position in the
physical/virtual topology. EIBP proposes to administratively
identify routers/networks with a tier value based on the structure.
*Localized forwarding semantics*: Approaches such as those outlined
in [REED] suggest using a novel forwarding semantic based on path
information carried in the packet itself, said path information
consists in a fixed size bitfield (see [REED] for more information on
how to represent the path information in said bitfield). In order to
utilize existing, e.g., SDN-based, forwarding switches, the direct
use of the IPv6 source/destination address is suggested for building
appropriate match-action rules (over the suitable binary information
representing the local output ports), while preserving the original
IPv6 information in the encapsulated packet. As mentioned above,
such use of the existing IPv6 address fields limits the size of the
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network to a maximum of 256 bits (therefore paths in the network over
which such packets can be forwarded). [ICNIP], however, goes a step
further by suggesting to use the local forwarding as direct network
layer mechanism, removing the IP packet and only leaving the
transport/application layer, with the path identifier constituting
the network-level identifier albeit limited by using the existing IP
header for backward compatibility reason (the next section outlines
the removal of this limitation).
3.3.2. Utilizing Existing or Extended Header Semantics
3.3.2.1. Description:
While the former sub-section explored extended address semantic,
thereby limiting any such extended semantic with that of the existing
IPv6 semantic and length, additional semantics may also be placed
into the header of the packet or the packet itself, utilized for the
forwarding decision to the appropriate endpoint according to the
extended semantic.
Reasons for embedding such new semantics may be related to traffic
engineering since it has long been shown that the IP address itself
is not enough to steer traffic properly since the IP address itself
is not semantically rich enough to adequately describe the forwarding
decision to be taken in the network, not only impacting WHERE the
packet will need to go but also HOW it will need to be sent.
3.3.2.2. Methodology:
*In-Header extensions*: One way to add additional semantic besides
the address fields is to use other fields already present in the
header.
*Headers option extensions*: Another mechanism to add additional
semantic is to actually add additional fields, e.g., through Header
Options in IPv4 or through Extension Headers in IPv6.
*Re-encapsulation extension*: A more radical approach for additional
semantic is the use of a complete new header that is designed so to
carry the desired semantic in an efficient way (often as a shim
header).
*Structured addressing*: Similar to the methodology that structures
addresses within the limitations of the IPv6 address length, outlined
in the previous sub-sections, structured addressing can also be
applied within existing or extended header semantics, e.g., utilizing
a dedicated (extension) header to carry the structured address
information.
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*Localized forwarding semantics*: This set of solutions apply
capabilities of newer (programmable) forwarding technology, such as
[P4], to utilize any header information for a localized forwarding
decision. This removes any limitation to use existing header or
address information for embedding a new address semantic into the
transferred packet.
3.3.2.3. Examples:
*In-Header extensions:* In order to allow additional semantic with
respect to the pure Internet addressing, the original design of IPv4
included the field "Type of Service" [RFC2474], while IPv6 introduced
the "Flow label" and the "Traffic Class" [RFC8200]. In a certain
way, those fields can be considered "semantic extensions" of IP
addresses, and they are "in-header" because natively present in the
IP header (differently from options and extension headers). However,
they proved not to be sufficient. Very often a variety of network
operation are performed on the well-known 5-tuple (source and
destination addresses; source and destination port number; and
protocol number). In some contexts all of the above mentioned fields
are used in order to have a very fine grained solution ([RFC8939]).
*Headers option extensions:* Header options have been largely under
exploited in IPv4. However, the introduction of the more efficient
extension header model in IPv6 along with technology progress made
the use of header extensions more widespread in IPv6. Segment
Routing re-introduced the possibility to add path semantic to the
packet by encoding a loosely defined source routing ([RFC8402]).
Similarly, in the aim to overcome the inherent shortcoming of the
multi-homing in the IP context, SHIM6 ([RFC5533]) also proposed the
use of an extension header able to carry multi-homing information
which cannot be accommodated natively in the IPv6 header.
To serve a moving endpoint, mechanisms like Mobile IPv6 [RFC6275] are
used for the maintenance of connection continuity by a dedicated IPv6
extension header. In such a case, the IP address of the home agent
in Mobile IPv6 is basically an identification of the on-going
communication. In order to go beyond the interface identification
model of IP, the Host Identity Protocol (HIP) tries to introduce an
identification layer to provide (as the name says) host
identification. The whole architecture relies on the use of another
type of extension header [RFC7401].
*Re-encapsulation extension:* Differently from the previous approach,
re-encapsulation prepends complete new IP headers to the original
packet introducing a completely custom shim header between the outer
and inner header. This is the case for LISP, adding a LISP specific
header right after an IP+UDP header ([I-D.ietf-lisp-rfc6830bis]). A
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similar design is used by VxLAN ([RFC7348]) and GENEVE ([RFC8926]),
even if they are designed for a data center context. IP packets can
also be wrapped with headers using more generic and semantically rich
names, for instance with ICN [ICNIP].
*Structured addressing:* Solutions such as those described in the
previous sub-section, e.g., EIBP [EIBP], can provide structured
addresses that are not limited to the IPv6 address length but instead
carry the information in an extension header to remove such
limitation.
Also information-centric networking (ICN) naming approaches usually
introduce structures in the (information) names without limiting
themselves to the IP address length; more so, ICN proposes its own
header format and therefore radically breaks with not only IP
addressing semantic but the format of the packet header overall. For
this, approaches such as those described in [RFC8609] define a TLV-
based binary application component structure that is carried as a
'name' part of the CCN messages. Such a name is a hierarchical
structure for identifying and locating a data object, which contains
a sequence of name components. Names are coded based on 2-level
nested Type-Length-Value (TLV) encodings, where the name-type field
in the outer TLV indicates this is a name, while the inner TLVs are
name components including a generic name component, an implicit
SHA-256 digest component and a SHA-256 digest of Interest parameters.
For textual representation, URIs are normally used to represent
names, as defined in [RFC3986].
In geographic addressing, position based routing protocols use the
geographic location of nodes as their addresses, and packets are
forwarded when possible in a greedy manner towards the destination.
For this purpose the packet header includes a field coding the
geographic coordinates (x, y, z) of the destination node, as defined
in [RFC2009]. Some proposals also rely on extra fields in the packet
header to code the distance towards the destination, in which case
only the geographic coordinates of neighbors are exchanged. This way
the location of the destination is protected even if routing packets
are eavesdropped.
*Localized forwarding semantics:* Unlike the original suggestion in
[REED] to use existing SDN switches, the proliferation of P4 [P4]
opens up the possibility to utilize a locally limited address
semantic, expressed through the path identifier, as an entirely new
header (including its new address) with an encapsulation of the IP
packet for E2E delivery (including further delivery outside the
localized forwarding network or positioning the limited address
semantic directly as the network address semantic for the packet,
i.e., removing any IP packet encapsulation from the forwarded packet,
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as done in [ICNIP]. Removing the IPv6 address size limitation by not
utilizing the existing IP header for the forwarding decision also
allows for extensible length approaches for building the path
identifier with the potential for increasing the supported network
size. On the downside, this approach requires to encapsulate the
original IP packet header for communication beyond the local domain
in which the new header is being used, such as discussed in the
previous point above on 're-encapsulation extension'.
3.3.3. Summary
Table 3, summarize the methodologies and the examples towards filling
the gaps on semantic extensions.
+---------------------------+------------------------+--------------+
| | Methodology | Examples |
+---------------------------+------------------------+--------------+
| Utilizing Extended | Semantic prefixes | HICN |
| Address Semantics | | |
| | | |
| | Separate device from | EIBP, ILNP, |
| | locator identifier | LISP, HIP |
| | | |
| | Structured addressing | EIBP, ILNP |
| | | |
| | Localized forwarding | REED |
| | semantics | |
| | | |
| Utilizing Existing or | In-Header extensions | DetNet |
| Extended Header Semantics | | |
| | | |
| | Headers option | SHIM6, SRv6, |
| | extensions | HIP |
| | | |
| | Re-encapsulation | VxLAN, ICNIP |
| | extension | |
| | | |
| | Structured addressing | EIBP |
| | | |
| | Localized forwarding | REED |
| | semantics | |
+---------------------------+------------------------+--------------+
Table 3: Summary Semantic Extensions
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4. Overview of Approaches to Extend Internet Addressing
From the view of the extensions, Table 4 describes the objectives
these extensions in extending the properties of Internet addressing.
As summarized, extensions may aim to extend one property of the
Internet addressing, or extend other properties at the same time.
+--------------+----------------+-----------------+-----------------+
| | Length | Identity | Semantic |
| | Extension | Extension | Extension |
+--------------+----------------+-----------------+-----------------+
| 6LoWPAN | x | | |
| | | | |
| ROHC | x | | |
| | | | |
| TOR | | x | |
| | | | |
| ODoH | | x | |
| | | | |
| SLAAC | | x | |
| | | | |
| CGA | | x | x |
| | | | |
| NAT | x | x | |
| | | | |
| HICN | | x | x |
| | | | |
| ICNIP | x | x | x |
| | | | |
| CCNx names | x | x | x |
| | | | |
| EIBP | x | x | x |
| | | | |
| Geo | x | | x |
| addressing | | | |
| | | | |
| REED | x (with P4) | | x |
| | | | |
| DetNet | | x | |
| | | | |
| Mobile IP | | | x |
| | | | |
| SHIM6 | | | x |
| | | | |
| SRv6 | | | x |
| | | | |
| HIP | | x | x |
| | | | |
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| VxLAN | | x | x |
| | | | |
| LISP | | x | x |
| | | | |
| SFC | | x | x |
+--------------+----------------+-----------------+-----------------+
Table 4: Relationship between Extensions and Internet Addressing
5. Issues in Extensions to Internet Addressing
While the extensions to the original Internet properties discussed in
Section 3 demonstrate the flexibility of the basic proposed
mechanisms, they also bring with them a number of issues, which we
discuss in the following section. For this, we outline the problems
caused, linking those to the approaches to extensions summarized in
Section 4.
5.1. Limiting Address Semantics
Many approaches changing the semantics of communication, e.g.,
through separating host identification from network node
identification [RFC7401], separating the device identifier from the
routing locator ([EIBP], [I-D.ietf-lisp-introduction]), or through
identifying content and services directly [HICN], are limited by the
existing packet size and semantic constraints of IPv6, e.g., in the
form of its source and destination network addresses.
While approaches such as [ICNIP] may override the addressing
semantics, e.g., by replacing IPv6 source and destination information
with path identification, a possible unawareness of endpoints still
requires the carrying of other address information as part of the
payload.
Also, the expressible service or content semantic may be limited, as
in [HICN] or the size of supported networks [REED] due to relying on
the limited bit positions usable in IPv6 addresses.
5.2. Complexity and Efficiency
A crucial issue is the additional complexity introduced for realizing
the additional addressing semantics. This is particularly an issue
since we see those additional semantics particularly at the edge of
the Internet, utilizing the existing addressing semantic of the
Internet to interconnect the domains that require those additional
semantics.
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Furthermore, any additional complexity can often come with an
efficiency and cost penalty, particularly at the edge of the network,
where resource constraints may play a significant role. Compression
processes, taking ROHC as an example, require additional resources
both for the sender generating the compressed header but also the
gateway linking to the general Internet by re-establishing the full
IP header (cf., [ROHC]).
Conversely, the performance requirements of core networks, in terms
of packet processing speed, make the accommodation of extensions to
addressing often prohibitive. This is not only due to the necessary
extra processing that is specific to the extension, but also due to
the complexity that will need to be managed in doing so at
significantly higher speeds than at the edge of the network. The
observations on the dropping of packets with IPv6 extension headers
in the real world is (partially) due to such a implementation
complexity [RFC7872].
Another example for lowering the efficiency of packet forwarding is
the routing in systems like TOR [TOR]. As detailed before, traffic
in TOR, for anonymity purposes, should be handed over by at least
three intermediates before reaching the destination. Thus, frequent
relaying enhances the privacy, however, because such kind of
solutions have to be implemented at application level, which comes at
the cost of lower communication efficiency. May be a different
privacy enhanced address semantic would enable efficient
implementation of TOR-like solutions at network layer.
5.2.1. Repetitive encapsulation
Repetitive encapsulation is an issue 'bloating' packet sizes with
additional encapsulation headers. Addressing proposals such as those
in [ICNIP] utilize path identification within an alternative
forwarding architecture that acts upon the provided path
identification. However, due to the limitation of existing flow-
based architectures with respect to the supported header structures
(in the form of IPv4 or IPv6 headers), the new routing semantics are
being inserted into the existing header structure, while repeating
the original, sender-generated header structure, in the payload of
the packet as it traverses the local domain, effectively doubling the
header overhead per packet.
The problem is also present in a number of solutions tackling
different issues, e.g., mobility [I-D.ietf-lisp-mn], DC networking
([RFC8926], [RFC7348], [I-D.ietf-intarea-gue]), traffic engineering
[RFC8986], and privacy ([TOR], [SPHINX]). Certainly these solutions
are able to avoid other issues, like path lengthening or privacy
issues, as described later, but they come at the price of multiple
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encapsulations that reduce the effective payload. This not only
hampers efficiency in terms of header-to-payload ratio but also
introduces "encapsulation points", which in turn add complexity to
the (often edge) network as well as fragility due to introducing
possible failure points; we discuss this aspect more in Section 5.4.
5.2.2. Compounding issues with header compression
IP header overhead requires header compression in constrained
environments, such as wireless sensor networks and IoT in general.
Together with fragmentation, both tasks constitute significant energy
consumption, as shown in [HEADER_COMP_ISSUES1], negatively impacting
reduced function devices that often rely on battery for operation.
Further, the reliance on the compression/decompression points creates
a dependence on such gateways, which may be a problem for
intermittent scenarios.
According to implementation of _contiki-ng_ [CONTIKI], an example of
operating system for IoT devices, the source codes for 6LowPan
requires at least 600kb to include a header compression process. In
certain use cases, such requirement can be an obstacle for extremely
constrained devices, especially for the RAM and energy consumption.
5.2.3. Introducing Path Stretch
Mobile IP [RFC6275], which was designed for connection continuity in
the face of moving endpoints, is a typical case for path stretch.
Since traffic must follow a triangular route before arriving at the
destination, such detour routing inevitably impacts transmission
efficiency as well as latency.
5.2.4. Complicating Traffic Engineering
While many extensions to the original IP address semantic target to
enrich the decisions that can be taken to steer traffic according to
requirements for, e.g., QoS, mobility, chaining, compute/network
metrics, flow treatment, path usage, etc., the realization of the
mechanisms as individual solutions likely complicates the original
goal of traffic engineering when individual solutions are being used
in combination. Ultimately, this may even prevent the combined use
of more than one mechanism and/or policies with a need to identify
and prevent incompatibilities of mechanisms. Key here is not the
issue arising from using conflicting traffic engineering polices but
conflicting realizations of policies that may well generally work
well alongside ([ROBUSTSDN], [TRANSACTIONSDN]).
This not only increases fragility, as we will discuss separately in
Section 5.4, but also requires careful planning for which mechanisms
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to use and in which combination, likely needing human-in-the-loop
approaches alongside possible automation approaches for the
individual solutions.
5.3. Security
The properties described in Section 2 have, obviously, also
consequences in terms of security and privacy related issues, as
already mentioned in other parts of this document.
For instance, in the effort of being somehow backward compatible, HIP
[RFC7401] uses 128-bit Host Identity, which may be not sufficiently
cryptographically strong in the future because of the limited size
(future computational power may erode 128-bit security). Similarly,
CGA [RFC3972] also align to the 128-bit limit but may use only 59
bits of them, hence, the packet signature may not be sufficiently
robust to attacks [I-D.rafiee-6man-cga-attack].
IP addresses, even temporary ones meant to protect privacy, have been
long recognized as a "Personal Identification Information" that
allows even to geolocate the communicating endpoints [RFC8280]. The
use of temporary addresses provides sufficient privacy protection
only if the renewal rate is high [EPHEMERALv6]. However, this causes
additional issues, like the large overhead due to the Duplicate
Address Detection, the impact on the Neighbor Discovery mechanism, in
particular the cache, which can even lead to communication
disruption. With such drawbacks, the extensions may even lead to
defeat the target actually lowering security rather than increasing
it.
The introduction of alternative addressing semantics has also been
used to help in (D)DoS attacks mitigation. This leverages on
changing the service identification model so to avoid topological
information exposure, making the potential disruptions likely remain
limited [ADDRLESS]. However, this increased robustness to DDoS comes
at the price of important communication setup latency and fragility,
as discussed next.
5.4. Fragility
From the extensions discussed in Section 3, it is evident that having
alternative or additional address semantic and formats available for
making routing as well as forwarding decisions dependent on these, is
common place in the Internet. This, however, adds many extension-
specific translation/adaptation points, mapping the semantic and
format in one context into what is meaningful in another context, but
also, more importantly, creating a dependency towards an additional
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component, often without explicit exposure to the endpoints that
originally intended to communicate.
For instance, the re-writing of IP addresses to facilitate the use of
private address spaces throughout the public Internet, realized
through network address translators (NATs), conflicts with the end-
to-end nature of communication between two endpoints. Additional
(flow) state is required at the NAT middlebox to smoothly allow
communication, which in turn creates a dependency between the NAT and
the end-to-end communication between those endpoints, thus increasing
the fragility of the communication relation.
A similar situation arises when supporting constrained environments
through a header compression mechanism, adding the need for, e.g., a
ROHC [RFC5795] element in the communication path, with communication-
related compression state being held outside the communicating
endpoints. Failure will introduce some inefficiencies due to context
regeneration, which may affects the communicating endpoints,
increasing fragility of the system overall.
Such translation/adaptation between semantic extensions to the
original 'semantic' of an IP address is generally not avoidable when
accommodating more than a single universal semantic. However, the
solution-specific nature of every single extension is likely to
noticeably increase the fragility of the overall system, since
individual extensions will need to interact with other extensions
that may be deployed in parallel, but were not designed taking into
account such deployment scenario (cf., [I-D.ietf-intarea-tunnels]).
Considering that extensions to traditional per-hop-behavior (based on
IP addresses) can essentially be realized over almost 'any' packet
field, the possible number of conflicting behaviors or diverging
interpretation of the semantic and/or content of such fields, among
different extensions, may soon become an issue, requiring careful
testing and delineation at the boundaries of the network within which
the specific extension has been realized.
6. Summary of issues in Extensions to Internet Addressing
Table 5, derived from Section 5, summarize the issues related to each
of the extension. As summarized, each extension involves at least
one issue. For extension like ICNIP, several issues may be involved
at the same time. Further, as explained in Section 5.4, "fragility"
does not mean that the extensions are fragile per-se, they are robust
for the task they have been designed for, rather we refer to the
existence of additional components that may fail (as Murphy's law
teach us), hence, making the overall system more fragile.
+------------+--------------+----------------+----------+-----------+
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| | Limiting | Complexity and | Security | Fragility |
| | Address | Efficiency | | |
| | Semantics | | | |
+------------+--------------+----------------+----------+-----------+
| 6LoWPAN | | x | | x |
| | | | | |
| ROHC | | x | | x |
| | | | | |
| TOR | | x | | x |
| | | | | |
| ODoH | | x | | |
| | | | | |
| SLAAC | | x | | |
| | | | | |
| CGA | x | | x | |
| | | | | |
| NAT | | x | | x |
| | | | | |
| HICN | x | | | |
| | | | | |
| ICNIP | x | x | | |
| | | | | |
| CCNx name | x | | | |
| | | | | |
| EIBP | x | x | | |
| | | | | |
| Geo | x | | | x |
| addressing | | | | |
| | | | | |
| REED | x | | | |
| | | | | |
| DetNet | | x | | |
| | | | | |
| Mobile IP | | x | | x |
| | | | | |
| SHIM6 | | | | x |
| | | | | |
| SRv6 | | | | x |
| | | | | |
| HIP | | | x | x |
| | | | | |
| VxLAN | | x | | |
| | | | | |
| LISP | x | x | | |
| | | | | |
| SFC | | x | | x |
+------------+--------------+----------------+----------+-----------+
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Table 5: Issues in Extensions to Internet Addressing
7. Conclusions
The examples of extensions discussed in Section 3 to the original
Internet addressing scheme show that extensibility beyond the
original model (and its underlying per-hop behavior) is a desired
capability for networking technologies and has been so for a long
time. Generally, we can observe that those extensions are driven by
the requirements of stakeholders, expecting a desirable extended
functionality from the introduction of the specific extension. If
interoperability is required, those extensions require
standardization of possibly new fields, new semantics as well as
(network and/or end system) operations alike.
One could argue that the power of the packet header (and the entire
packet for that matter) lies in its potential to be used for
extensions that satisfy the various requirements of those developing
the extensions with given deployments and use cases in mind. The
author in [EXPRESSIVE-POWER] argues that this capability represents
the 'expressive power of the Internet design', with developments such
as Software-Defined Networking (SDN) enabling per-hop operations (to
be specified in dedicated match-action rules) that take more than
just the IP address as input, even beyond the strict IP header,
albeit still limited to certain packet header(s) fields, as in the
OpenFlow specification [OPENFLOW].
Beyond the fragility, discussed in this document, caused by adding,
overriding, amending semantics and behaviors (and deploying them in a
running system), such approach to extensibility that opens up other
header fields may, however, also be limiting the realization of per-
hop operations. As an example, although the authors in [REED]
utilize the power of SDN to enable extension-specific per-hop
behaviors that follow path-based rather than endpoint locator
semantics, they do so within the limitation of currently supported
header fields in SDN. The result is the overriding of the IPv6
source/destination address with the semantic input (here the path
forwarding identifier) for the desired per-hop behavior, which in
turn creates the need for border translation to avoid 'leaking' such
(malformed) IPv6-like packet into a standard IPv6 network. Leaving
the IPv6 address information intact albeit unused is not possible due
to the lack of accommodating the extended per-hop behavior
information needed for the proposed solution.
Since the publication of [REED] (and its realization in existing real
world trials), the newer P4 technology has removed this limitation,
therefore positioning the entire packet content as input into per-hop
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behavior and removing the need for overriding existing packet fields
and restoring their semantics at the borders of the network.
We see such evolution of per-hop behavior implementation as closing
the loop to approaches to addressing considered in early days of the
packet-based networking [RFC0757][POSTEL], based on structured and
flexible addresses, similar to the heap or stack model suggestions
found in [EXPRESSIVE-POWER]. We believe that approaching addressing
from such desire to enable extensions by design rather than through a
pure extension engineering approach would also address possible
fragility and security issues due to unwanted interactions between
possibly incompatible extensions, while also enabling more efficient
realization of the extensions through a common execution point in the
forwarding element.
The issues we identified with the extension-specific solution
approach, point to the need for a discussion on Internet addressing,
as formulated in the companion document
[I-D.jia-intarea-scenarios-problems-addressing] that formalizes the
problem statement through scenarios that highlight the shortcomings
of the Internet addressing model.
It is our conclusion that the existence of the many extensions to the
original Internet addressing is clear evidence for gaps that have
been identified over time by the wider Internet community: it is time
to develop an architectural but more importantly a sustainable
approach to make Internet addressing extensible in order to capture
the many new uses we will still identify for the Internet to come.
Any inaction on our side in that regard will only compound the issues
we identified, eventually hampering the future Internet's readiness
for those new uses.
8. Security Considerations
The present memo does not introduce any new technology and/or
mechanism and as such does not introduce any security threat to the
TCP/IP protocol suite.
As an additional note, and as we discussed in this document, security
and privacy aspects were not considered as part of the key properties
for Internet addressing, which led to the introduction of a number of
extensions intending to fix those gaps. The analysis presented in
this memo (non-exhaustively) shows those issues are either solved in
an ad-hoc manner at application level, or at transport layer, while
at network level only few extensions tackling specific aspects exist
albeit often with limitations due to the adherence to the Internet
addressing model and its properties.
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9. IANA Considerations
This document does not include any IANA request.
10. Informative References
[ADDRLESS]
Hao, S., Liu, R., Weng, Z., Chang, D., Bao, C., and X. Li,
"Addressless: A new internet server model to prevent
network scanning", PLOS ONE Vol. 16, pp. e0246293,
DOI 10.1371/journal.pone.0246293, February 2021.
[CONTIKI] "Contiki-NG: The OS for Next Generation IoT Devices",
n.d., <https://github.com/contiki-ng/contiki-ng>.
[EIBP] Willis, N., "A Structured Approach to Routing in the
Internet", June 2021, <First Intl Workshop on Semantic
Addressing and Routing for Future Networks>.
[EPHEMERALv6]
Gont, F. and G. Gont, "IPv6 Addressing Considerations",
draft-gont-v6ops-ipv6-addressing-considerations-01 (work
in progress), February 2021.
[EXPRESSIVE-POWER]
Clark, D., "The expressive power of the Internet design",
April 2009, <http://groups.csail.mit.edu/ana/People/DDC/
Expressive%20power%205.pdf>.
[GDPR] Voigt, P. and A. von dem Bussche, "The EU General Data
Protection Regulation (GDPR)", Springer International
Publishing book, DOI 10.1007/978-3-319-57959-7, 2017.
[GNATCATCHER]
"Global Network Address Translation Combined with Audited
and Trusted CDN or HTTP-Proxy Eliminating
Reidentification", n.d.,
<https://github.com/bslassey/ip-blindness>.
[HEADER_COMP_ISSUES1]
Mesrinejad, F., Hashim, F., Noordin, N., Rasid, M., and R.
Abdullah, "The effect of fragmentation and header
compression on IP-based sensor networks (6LoWPAN)", The
17th Asia Pacific Conference on Communications,
DOI 10.1109/apcc.2011.6152926, October 2011.
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[HICN] Muscariello, L., "Hybrid Information-Centric Networking:
ICN inside the Internet Protocol", March 2018,
<https://datatracker.ietf.org/meeting/interim-2018-icnrg-
01/materials/slides-interim-2018-icnrg-01-sessa-hybrid-
icn-hicn-luca-muscariello>.
[HISTORY127]
"History of 127/8 as localhost/loopback addresses", n.d.,
<https://elists.isoc.org/pipermail/internet-
history/2021-January/006920.html>.
[I-D.ietf-6lo-nfc]
Choi, Y., Hong, Y., Youn, J., Kim, D., and J. Choi,
"Transmission of IPv6 Packets over Near Field
Communication", draft-ietf-6lo-nfc-17 (work in progress),
August 2020.
[I-D.ietf-6lo-plc]
Hou, J., Liu, B., Hong, Y., Tang, X., and C. E. Perkins,
"Transmission of IPv6 Packets over PLC Networks", draft-
ietf-6lo-plc-06 (work in progress), April 2021.
[I-D.ietf-intarea-gue]
Herbert, T., Yong, L., and O. Zia, "Generic UDP
Encapsulation", draft-ietf-intarea-gue-09 (work in
progress), October 2019.
[I-D.ietf-intarea-tunnels]
Touch, J. and M. Townsley, "IP Tunnels in the Internet
Architecture", draft-ietf-intarea-tunnels-10 (work in
progress), September 2019.
[I-D.ietf-lisp-introduction]
Cabellos, A. and D. Saucez, "An Architectural Introduction
to the Locator/ID Separation Protocol (LISP)", draft-ietf-
lisp-introduction-13 (work in progress), April 2015.
[I-D.ietf-lisp-mn]
Farinacci, D., Lewis, D., Meyer, D., and C. White, "LISP
Mobile Node", draft-ietf-lisp-mn-09 (work in progress),
February 2021.
[I-D.ietf-lisp-rfc6830bis]
Farinacci, D., Fuller, V., Meyer, D., Lewis, D., and A.
Cabellos, "The Locator/ID Separation Protocol (LISP)",
draft-ietf-lisp-rfc6830bis-36 (work in progress), November
2020.
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[I-D.ietf-lisp-rfc6833bis]
Farinacci, D., Maino, F., Fuller, V., and A. Cabellos,
"Locator/ID Separation Protocol (LISP) Control-Plane",
draft-ietf-lisp-rfc6833bis-30 (work in progress), November
2020.
[I-D.jia-intarea-scenarios-problems-addressing]
Jia, Y., Trossen, D., Iannone, L., 3rd, D. E. E., and P.
Liu, "Challenging Scenarios and Problems in Internet
Addressing", draft-jia-intarea-scenarios-problems-
addressing-00 (work in progress), February 2021.
[I-D.rafiee-6man-cga-attack]
Rafiee, H. and C. Meinel, "Possible Attack on
Cryptographically Generated Addresses (CGA)", draft-
rafiee-6man-cga-attack-03 (work in progress), May 2015.
[ICNIP] Trossen, D., Robitzsch, S., Reed, M., Al-Naday, M., and J.
Riihijarvi, "Internet Services over ICN in 5G LAN
Environments", draft-trossen-icnrg-internet-icn-5glan-04
(work in progress), October 2020.
[ITU9959] Badenhop, C., Fuller, J., Hall, J., Ramsey, B., and M.
Rice, "Evaluating ITU-T G.9959 Based Wireless Systems Used
in Critical Infrastructure Assets", IFIP Advances in
Information and Communication Technology pp. 209-227,
DOI 10.1007/978-3-319-26567-4_13, 2015.
[ODoH] Kinnear, E., McManus, P., Pauly, T., Verma, T., and C. A.
Wood, "Oblivious DNS Over HTTPS", draft-pauly-dprive-
oblivious-doh-06 (work in progress), March 2021.
[OHTTP] Thomson, M. and C. A. Wood, "Oblivious HTTP", draft-
thomson-http-oblivious-01 (work in progress), February
2021.
[ONION] Goldschlag, D., Reed, M., and P. Syverson, "Onion
routing", Communications of the ACM Vol. 42, pp. 39-41,
DOI 10.1145/293411.293443, February 1999.
[OPENFLOW]
McKeown, N., Anderson, T., Balakrishnan, H., Parulkar, G.,
Peterson, L., Rexford, J., Shenker, S., and J. Turner,
"OpenFlow: enabling innovation in campus networks", ACM
SIGCOMM Computer Communication Review Vol. 38, pp. 69-74,
DOI 10.1145/1355734.1355746, March 2008.
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[P4] Bosshart, P., Daly, D., Gibb, G., Izzard, M., McKeown, N.,
Rexford, J., Schlesinger, C., Talayco, D., Vahdat, A.,
Varghese, G., and D. Walker, "P4: programming protocol-
independent packet processors", ACM SIGCOMM Computer
Communication Review Vol. 44, pp. 87-95,
DOI 10.1145/2656877.2656890, July 2014.
[POSTEL] Postel, J., "Internetwork Protocol Approaches", IEEE
Transactions on Communications Vol. 28, pp. 604-611,
DOI 10.1109/tcom.1980.1094705, April 1980.
[REED] Reed, M., Al-Naday, M., Thomos, N., Trossen, D.,
Petropoulos, G., and S. Spirou, "Stateless multicast
switching in software defined networks", 2016 IEEE
International Conference on Communications (ICC),
DOI 10.1109/icc.2016.7511036, May 2016.
[RFC0757] Deutsch, D., "Suggested solution to the naming,
addressing, and delivery problem for ARPANET message
systems", RFC 757, DOI 10.17487/RFC0757, September 1979,
<https://www.rfc-editor.org/info/rfc757>.
[RFC0791] Postel, J., "Internet Protocol", STD 5, RFC 791,
DOI 10.17487/RFC0791, September 1981,
<https://www.rfc-editor.org/info/rfc791>.
[RFC1752] Bradner, S. and A. Mankin, "The Recommendation for the IP
Next Generation Protocol", RFC 1752, DOI 10.17487/RFC1752,
January 1995, <https://www.rfc-editor.org/info/rfc1752>.
[RFC1918] Rekhter, Y., Moskowitz, B., Karrenberg, D., de Groot, G.,
and E. Lear, "Address Allocation for Private Internets",
BCP 5, RFC 1918, DOI 10.17487/RFC1918, February 1996,
<https://www.rfc-editor.org/info/rfc1918>.
[RFC2009] Imielinski, T. and J. Navas, "GPS-Based Addressing and
Routing", RFC 2009, DOI 10.17487/RFC2009, November 1996,
<https://www.rfc-editor.org/info/rfc2009>.
[RFC2101] Carpenter, B., Crowcroft, J., and Y. Rekhter, "IPv4
Address Behaviour Today", RFC 2101, DOI 10.17487/RFC2101,
February 1997, <https://www.rfc-editor.org/info/rfc2101>.
[RFC2474] Nichols, K., Blake, S., Baker, F., and D. Black,
"Definition of the Differentiated Services Field (DS
Field) in the IPv4 and IPv6 Headers", RFC 2474,
DOI 10.17487/RFC2474, December 1998,
<https://www.rfc-editor.org/info/rfc2474>.
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[RFC2663] Srisuresh, P. and M. Holdrege, "IP Network Address
Translator (NAT) Terminology and Considerations",
RFC 2663, DOI 10.17487/RFC2663, August 1999,
<https://www.rfc-editor.org/info/rfc2663>.
[RFC3118] Droms, R., Ed. and W. Arbaugh, Ed., "Authentication for
DHCP Messages", RFC 3118, DOI 10.17487/RFC3118, June 2001,
<https://www.rfc-editor.org/info/rfc3118>.
[RFC3972] Aura, T., "Cryptographically Generated Addresses (CGA)",
RFC 3972, DOI 10.17487/RFC3972, March 2005,
<https://www.rfc-editor.org/info/rfc3972>.
[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
Resource Identifier (URI): Generic Syntax", STD 66,
RFC 3986, DOI 10.17487/RFC3986, January 2005,
<https://www.rfc-editor.org/info/rfc3986>.
[RFC4014] Droms, R. and J. Schnizlein, "Remote Authentication Dial-
In User Service (RADIUS) Attributes Suboption for the
Dynamic Host Configuration Protocol (DHCP) Relay Agent
Information Option", RFC 4014, DOI 10.17487/RFC4014,
February 2005, <https://www.rfc-editor.org/info/rfc4014>.
[RFC4193] Hinden, R. and B. Haberman, "Unique Local IPv6 Unicast
Addresses", RFC 4193, DOI 10.17487/RFC4193, October 2005,
<https://www.rfc-editor.org/info/rfc4193>.
[RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing
Architecture", RFC 4291, DOI 10.17487/RFC4291, February
2006, <https://www.rfc-editor.org/info/rfc4291>.
[RFC4581] Bagnulo, M. and J. Arkko, "Cryptographically Generated
Addresses (CGA) Extension Field Format", RFC 4581,
DOI 10.17487/RFC4581, October 2006,
<https://www.rfc-editor.org/info/rfc4581>.
[RFC4982] Bagnulo, M. and J. Arkko, "Support for Multiple Hash
Algorithms in Cryptographically Generated Addresses
(CGAs)", RFC 4982, DOI 10.17487/RFC4982, July 2007,
<https://www.rfc-editor.org/info/rfc4982>.
[RFC5533] Nordmark, E. and M. Bagnulo, "Shim6: Level 3 Multihoming
Shim Protocol for IPv6", RFC 5533, DOI 10.17487/RFC5533,
June 2009, <https://www.rfc-editor.org/info/rfc5533>.
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[RFC5795] Sandlund, K., Pelletier, G., and L-E. Jonsson, "The RObust
Header Compression (ROHC) Framework", RFC 5795,
DOI 10.17487/RFC5795, March 2010,
<https://www.rfc-editor.org/info/rfc5795>.
[RFC6250] Thaler, D., "Evolution of the IP Model", RFC 6250,
DOI 10.17487/RFC6250, May 2011,
<https://www.rfc-editor.org/info/rfc6250>.
[RFC6275] Perkins, C., Ed., Johnson, D., and J. Arkko, "Mobility
Support in IPv6", RFC 6275, DOI 10.17487/RFC6275, July
2011, <https://www.rfc-editor.org/info/rfc6275>.
[RFC6282] Hui, J., Ed. and P. Thubert, "Compression Format for IPv6
Datagrams over IEEE 802.15.4-Based Networks", RFC 6282,
DOI 10.17487/RFC6282, September 2011,
<https://www.rfc-editor.org/info/rfc6282>.
[RFC6740] Atkinson, RJ. and SN. Bhatti, "Identifier-Locator Network
Protocol (ILNP) Architectural Description", RFC 6740,
DOI 10.17487/RFC6740, November 2012,
<https://www.rfc-editor.org/info/rfc6740>.
[RFC7228] Bormann, C., Ersue, M., and A. Keranen, "Terminology for
Constrained-Node Networks", RFC 7228,
DOI 10.17487/RFC7228, May 2014,
<https://www.rfc-editor.org/info/rfc7228>.
[RFC7258] Farrell, S. and H. Tschofenig, "Pervasive Monitoring Is an
Attack", BCP 188, RFC 7258, DOI 10.17487/RFC7258, May
2014, <https://www.rfc-editor.org/info/rfc7258>.
[RFC7348] Mahalingam, M., Dutt, D., Duda, K., Agarwal, P., Kreeger,
L., Sridhar, T., Bursell, M., and C. Wright, "Virtual
eXtensible Local Area Network (VXLAN): A Framework for
Overlaying Virtualized Layer 2 Networks over Layer 3
Networks", RFC 7348, DOI 10.17487/RFC7348, August 2014,
<https://www.rfc-editor.org/info/rfc7348>.
[RFC7400] Bormann, C., "6LoWPAN-GHC: Generic Header Compression for
IPv6 over Low-Power Wireless Personal Area Networks
(6LoWPANs)", RFC 7400, DOI 10.17487/RFC7400, November
2014, <https://www.rfc-editor.org/info/rfc7400>.
[RFC7401] Moskowitz, R., Ed., Heer, T., Jokela, P., and T.
Henderson, "Host Identity Protocol Version 2 (HIPv2)",
RFC 7401, DOI 10.17487/RFC7401, April 2015,
<https://www.rfc-editor.org/info/rfc7401>.
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[RFC7665] Halpern, J., Ed. and C. Pignataro, Ed., "Service Function
Chaining (SFC) Architecture", RFC 7665,
DOI 10.17487/RFC7665, October 2015,
<https://www.rfc-editor.org/info/rfc7665>.
[RFC7872] Gont, F., Linkova, J., Chown, T., and W. Liu,
"Observations on the Dropping of Packets with IPv6
Extension Headers in the Real World", RFC 7872,
DOI 10.17487/RFC7872, June 2016,
<https://www.rfc-editor.org/info/rfc7872>.
[RFC8060] Farinacci, D., Meyer, D., and J. Snijders, "LISP Canonical
Address Format (LCAF)", RFC 8060, DOI 10.17487/RFC8060,
February 2017, <https://www.rfc-editor.org/info/rfc8060>.
[RFC8061] Farinacci, D. and B. Weis, "Locator/ID Separation Protocol
(LISP) Data-Plane Confidentiality", RFC 8061,
DOI 10.17487/RFC8061, February 2017,
<https://www.rfc-editor.org/info/rfc8061>.
[RFC8105] Mariager, P., Petersen, J., Ed., Shelby, Z., Van de Logt,
M., and D. Barthel, "Transmission of IPv6 Packets over
Digital Enhanced Cordless Telecommunications (DECT) Ultra
Low Energy (ULE)", RFC 8105, DOI 10.17487/RFC8105, May
2017, <https://www.rfc-editor.org/info/rfc8105>.
[RFC8163] Lynn, K., Ed., Martocci, J., Neilson, C., and S.
Donaldson, "Transmission of IPv6 over Master-Slave/Token-
Passing (MS/TP) Networks", RFC 8163, DOI 10.17487/RFC8163,
May 2017, <https://www.rfc-editor.org/info/rfc8163>.
[RFC8200] Deering, S. and R. Hinden, "Internet Protocol, Version 6
(IPv6) Specification", STD 86, RFC 8200,
DOI 10.17487/RFC8200, July 2017,
<https://www.rfc-editor.org/info/rfc8200>.
[RFC8280] ten Oever, N. and C. Cath, "Research into Human Rights
Protocol Considerations", RFC 8280, DOI 10.17487/RFC8280,
October 2017, <https://www.rfc-editor.org/info/rfc8280>.
[RFC8376] Farrell, S., Ed., "Low-Power Wide Area Network (LPWAN)
Overview", RFC 8376, DOI 10.17487/RFC8376, May 2018,
<https://www.rfc-editor.org/info/rfc8376>.
[RFC8402] Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L.,
Decraene, B., Litkowski, S., and R. Shakir, "Segment
Routing Architecture", RFC 8402, DOI 10.17487/RFC8402,
July 2018, <https://www.rfc-editor.org/info/rfc8402>.
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[RFC8484] Hoffman, P. and P. McManus, "DNS Queries over HTTPS
(DoH)", RFC 8484, DOI 10.17487/RFC8484, October 2018,
<https://www.rfc-editor.org/info/rfc8484>.
[RFC8609] Mosko, M., Solis, I., and C. Wood, "Content-Centric
Networking (CCNx) Messages in TLV Format", RFC 8609,
DOI 10.17487/RFC8609, July 2019,
<https://www.rfc-editor.org/info/rfc8609>.
[RFC8724] Minaburo, A., Toutain, L., Gomez, C., Barthel, D., and JC.
Zuniga, "SCHC: Generic Framework for Static Context Header
Compression and Fragmentation", RFC 8724,
DOI 10.17487/RFC8724, April 2020,
<https://www.rfc-editor.org/info/rfc8724>.
[RFC8926] Gross, J., Ed., Ganga, I., Ed., and T. Sridhar, Ed.,
"Geneve: Generic Network Virtualization Encapsulation",
RFC 8926, DOI 10.17487/RFC8926, November 2020,
<https://www.rfc-editor.org/info/rfc8926>.
[RFC8939] Varga, B., Ed., Farkas, J., Berger, L., Fedyk, D., and S.
Bryant, "Deterministic Networking (DetNet) Data Plane:
IP", RFC 8939, DOI 10.17487/RFC8939, November 2020,
<https://www.rfc-editor.org/info/rfc8939>.
[RFC8981] Gont, F., Krishnan, S., Narten, T., and R. Draves,
"Temporary Address Extensions for Stateless Address
Autoconfiguration in IPv6", RFC 8981,
DOI 10.17487/RFC8981, February 2021,
<https://www.rfc-editor.org/info/rfc8981>.
[RFC8986] Filsfils, C., Ed., Camarillo, P., Ed., Leddy, J., Voyer,
D., Matsushima, S., and Z. Li, "Segment Routing over IPv6
(SRv6) Network Programming", RFC 8986,
DOI 10.17487/RFC8986, February 2021,
<https://www.rfc-editor.org/info/rfc8986>.
[ROBUSTSDN]
Canini, M., Kuznetsov, P., Levin, D., and S. Schmid, "A
distributed and robust SDN control plane for transactional
network updates", 2015 IEEE Conference on Computer
Communications (INFOCOM),
DOI 10.1109/infocom.2015.7218382, April 2015.
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[ROHC] Fitzek, F., Rein, S., Seeling, P., and M. Reisslein,
"RObust Header Compression (ROHC) Performance for
Multimedia Transmission over 3G/4G Wireless Networks",
Wireless Personal Communications Vol. 32, pp. 23-41,
DOI 10.1007/s11277-005-7733-2, January 2005.
[SFCANYCAST]
Wion, A., Bouet, M., Iannone, L., and V. Conan,
"Distributed Function Chaining with Anycast Routing",
Proceedings of the 2019 ACM Symposium on SDN Research,
DOI 10.1145/3314148.3314355, April 2019.
[SPHINX] Danezis, G. and I. Goldberg, "Sphinx: A Compact and
Provably Secure Mix Format", 2009 30th IEEE Symposium on
Security and Privacy, DOI 10.1109/sp.2009.15, May 2009.
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Acknowledgments
Thanks to Carsten Bormann for useful conversations.
Authors' Addresses
Jia, et al. Expires January 13, 2022 [Page 38]
Internet-Draft Gap Analysis in Internet Addressing July 2021
Yihao Jia
Huawei Technologies Co., Ltd
156 Beiqing Rd.
Beijing 100095
P.R. China
Email: jiayihao@huawei.com
Dirk Trossen
Huawei Technologies Duesseldorf GmbH
Riesstr. 25C
Munich 80992
Germany
Email: dirk.trossen@huawei.com
Luigi Iannone
Huawei Technologies France S.A.S.U.
18, Quai du Point du Jour
Boulogne-Billancourt 92100
France
Email: luigi.iannone@huawei.com
Nirmala Shenoy
Rochester Institute of Technology
New-York 14623
USA
Email: nxsvks@rit.edu
Paulo Mendes
Airbus
Willy-Messerschmitt Strasse 1
Munich 81663
Germany
Email: paulo.mendes@airbus.com
Jia, et al. Expires January 13, 2022 [Page 39]