Internet Draft RJ Atkinson
draft-irtf-rrg-ilnp-dns-06.txt Consultant
Expires: 10 JAN 2013 SN Bhatti
Category: Experimental U. St Andrews
Scott Rose
US NIST
10 July 2012
DNS Resource Records for ILNP
draft-irtf-rrg-ilnp-dns-06.txt
STATUS OF THIS MEMO
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Internet-Drafts are working documents of the Internet
Engineering Task Force (IETF), its areas, and its working
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groups. Note that other groups may also distribute working
documents as Internet-Drafts.
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."
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/1id-abstracts.html
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html
This document is not on the IETF standards-track and does not
specify any level of standard. This document merely provides
information for the Internet community.
This document is part of the ILNP document set, which has had
extensive review within the IRTF Routing Research Group. ILNP is
one of the recommendations made by the RG Chairs. Separately,
various refereed research papers on ILNP have also been published
during this decade. So the ideas contained herein have had much
broader review than the IRTF Routing RG. The views in this
document were considered controversial by the Routing RG, but the
RG reached a consensus that the document still should be
published. The Routing RG has had remarkably little consensus on
anything, so virtually all Routing RG outputs are considered
controversial.
ABSTRACT
This note describes additional optional Resource Records for use
with the Domain Name System (DNS). These optional resource
records are for use with the Identifier-Locator Network Protocol
(ILNP). This document is a product of the IRTF Routing RG.
TABLE OF CONTENTS
1. Introduction.............................2
2. New Resource Records.....................3
2.1 NID Resource Record.....................3
2.2 L32 Resource Record......................5
2.3 L64 Resource Record......................6
2.4 LP Resource Record.......................7
3. Usage Example............................8
4. Security Considerations..................9
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5. IANA Considerations......................9
6. References...............................9
1. INTRODUCTION
At present, the Internet research and development community are
exploring various approaches to evolving the Internet
Architecture to solve a variety of issues including, but not
limited to, scalability of inter-domain routing [RFC4984]. A wide
range of other issues (e.g. site multi-homing, node multi-homing,
site/subnet mobility, node mobility) are also active concerns at
present. Several different classes of evolution are being
considered by the Internet research & development community. One
class is often called "Map and Encapsulate", where traffic would
be mapped and then tunnelled through the inter-domain core of the
Internet. Another class being considered is sometimes known as
"Identifier/Locator Split". This document relates to a proposal
that is in the latter class of evolutionary approaches.
The Identifier-Locator Network Protocol (ILNP) was developed to
explore a possible evolutionary direction for the Internet
Architecture. An description of the ILNP architecture is
available in a separate document [ILNP-ARCH]. Implementation and
engineering details are largely isolated into a second document
[ILNP-ENG].
The Domain Name System (DNS) is the standard way that Internet
nodes locate information about addresses, mail exchangers, and
other data relating to remote Internet nodes [RFC1034] [RFC1035].
More recently, the IETF have defined standards-track security
extensions to the DNS [RFC4033]. These security extensions can
be used to authenticate signed DNS data records and can also be
used to store signed public keys in the DNS. Further, the IETF
have defined a standards-track approach to enable secure dynamic
update of DNS records over the network [RFC3007].
This document defines several new optional data Resource
Records. This note specifies the syntax and other items
required for independent implementations of these DNS resource
records. The reader is assumed to be familiar with the basics
of DNS, including familiarity with [RFC1034] [RFC1035].
The concept of using DNS for rendezvous with mobile nodes or
mobile networks has been proposed earlier, more than once,
independently, by several other researchers; for example,
please see [SB00] [SBK01] and [PHG02].
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1.1 Document roadmap
This document describes defines additional DNS resource records
that support ILNP.
The ILNP architecture can have more than one engineering
instantiation. For example, one can imagine a "clean-slate"
engineering design based on the ILNP architecture. In separate
documents, we describe two specific engineering instances of
ILNP. The term ILNPv6 refers precisely to an instance of ILNP that
is based upon, and backwards compatible with, IPv6. The term ILNPv4
refers precisely to an instance of ILNP that is based upon, and
backwards compatible with, IPv4.
Many engineering aspects common to both ILNPv4 and ILNPv6 are
described in [ILNP-ENG]. A full engineering specification for
either ILNPv6 or ILNPv4 is beyond the scope of this document.
Readers are referred to other related ILNP documents for details
not described here:
a) [ILNP-ARCH] is the main architectural description of ILNP,
including the concept of operations.
b) [ILNP-ENG] describes engineering and implementation
considerations that are common to both ILNPv4 and ILNPv6.
c) [ILNP-ICMPv6] defines a new ICMPv6 Locator Update message
used by an ILNP node to inform its correspondent nodes
of any changes to its set of valid Locators.
d) [ILNP-NONCEv6] defines a new IPv6 Nonce Destination Option
used by ILNPv6 nodes (1) to indicate to ILNP correspondent
nodes (by inclusion within the initial packets of an ILNP
session) that the node is operating in the ILNP mode and
(2) to prevent off-path attacks against ILNP ICMP messages.
This Nonce is used, for example, with all ILNP ICMPv6
Locator Update messages that are exchanged among ILNP
correspondent nodes.
e) [ILNP-ICMPv4] defines a new ICMPv4 Locator Update message
used by an ILNP node to inform its correspondent nodes
of any changes to its set of valid Locators.
f) [ILNP-v4OPTS] defines a new IPv4 Nonce Option used by ILNPv4
nodes to carry a security nonce to prevent off-path attacks
against ILNP ICMP messages and also defines a new IPv4
Identifier Option used by ILNPv4 nodes.
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g) [ILNP-ARP] describes extensions to ARP for use with ILNPv4.
h) [ILNP-ADV] describes optional engineering and deployment
functions for ILNP. These are not required for the operation
or use of ILNP and are provided as additional options.
1.2 Terminology
In this document, the term "ILNP-aware" applied to a DNS
component (either authoritative server or cache) is used to
indicate that the component attempts to include other ILNP
RRTypes to the Additional section of a DNS response to
increase performance and reduce the number of follow-up
queries for other ILNP RRTypes. These other RRsets MAY be added
to the Additional section if space permits and only when the
QTYPE equals NID, L64, L32, or LP. There is no method for a
server to signal that it is ILNP-aware.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL
NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described
in RFC 2119 [RFC2119].
2. NEW RESOURCE RECORDS
This document specifies several new and closely related DNS data
Resource Records (RRs). These new RR types have the mnemonics
"NID", "L32", "L64", and "LP". These resource record types are
associated with a Fully-Qualified Domain Name (FQDN), that is
hereafter called the "owner name". These are part of work on the
Identifier-Locator Network Protocol (ILNP) [ILNP-ARCH].
For clarity, throughout this section of this document, the
"RDATA" subsections specify the on-the-wire format for these
records, while the "Presentation Format" subsections specify the
human-readable format used in a DNS configuration file
(i.e. "master file" as defined by RFC-1035, Section 5.1).
2.1 The NID Resource Record
The NID DNS Resource Record (RR) is used hold values for Node
Identifiers that will be used for ILNP-capable nodes.
NID records are present only for ILNP-capable nodes. This
restriction is important; ILNP-capable nodes use the presence of
NID records in the DNS to learn that a correspondent node is also
ILNP-capable. While erroneous NID records in the DNS for an node
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that is not ILNP-capable would not prevent communication, such
erroneous DNS records could increase the delay at the start of an
IP session.
A given owner name may have zero or more NID records at a given
time. In normal operation, nodes that support the Identifier-
Locator Network Protocol (ILNP) will have at least one valid NID
record.
The type value for the NID RR type is X-NID-X <to be assigned>.
The NID RR is class independent.
The NID RR has no special TTL requirements.
2.1.1 NID RDATA wire format
The RDATA for an NID RR consists of:
- a 16 bit Preference field
- a 64 bit NodeID field
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Preference | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +
| NodeID |
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2.1.1.1 The Preference field
The <Preference> field contains a 16-bit unsigned integer in
network byte-order that indicates the owner name's relative
preference for this NID record among other NID records associated
with this owner name. Lower Preference values are preferred over
higher Preference values.
2.1.1.2 The NodeID field
The NodeID field is an unsigned 64-bit value in network
byte-order. It complies with the syntactic rules of IPv6
Interface Identifiers [RFC-4291, Section 2.5.1], but has slightly
different semantics. Unlike IPv6 Interface Identifiers, which are
bound to a specific *interface* of a specific node, NodeID values
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are bound to a specific *node*, and MAY be used with *any
interface* of that node.
2.1.2 NID RR Presentation Format
The presentation of the format of the RDATA portion is as follows:
- The Preference field MUST be represented as a 16-bit unsigned
decimal integer.
- The NodeID field MUST be represented using the same syntax
(i.e. groups of 4 hexadecimal digits, with each group
separated by a colon) that is already used for DNS AAAA
records (and also used for IPv6 Interface IDs).
- The NodeID value MUST NOT be in the 'compressed' format
(e.g. using "::") that is defined in RFC-4291, Section 2.2
(2). This restriction exists to avoid confusion with 128-bit
IPv6 addresses, because the NID is a 64-bit field.
2.1.3 NID RR Examples
An NID record has the following logical components:
<owner-name> IN NID <Preference> <NodeID>
In the above, <owner-name> is the owner name string, <Preference>
is an unsigned 16-bit value, and <NodeID> is an unsigned 64-bit
value.
host1.example.com. IN NID 10 0014:4fff:ff20:ee64
host1.example.com. IN NID 20 0015:5fff:ff21:ee65
host2.example.com. IN NID 10 0016:6fff:ff22:ee66
As NodeID values use the same syntax as IPv6 interface
identifiers, when displayed for human readership, the NodeID
values are presented in the same hexadecimal format as IPv6
interface identifiers. This is shown in the example above.
2.1.4 Additional Section Processing
To improve performance, ILNP-aware DNS servers and DNS resolvers
MAY attempt to return all L32, L64, and LP records for the same
owner name of the NID RRset in the Additional section of the
response, if space permits.
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2.2 The L32 Resource Record
An L32 DNS Resource Record (RR) is used to hold 32-bit
Locator values for ILNPv4-capable nodes.
L32 records are present only for ILNPv4-capable nodes. This
restriction is important; ILNP-capable nodes use the presence of
L32 records in the DNS to learn that a correspondent node is also
ILNPv4-capable. While erroneous L32 records in the DNS for a
node that is not ILNP-capable would not prevent communication,
such erroneous DNS records could increase the delay at the start
of an IP session.
A given owner name might have zero or more L32 values at a given
time. An ILNPv4-capable host SHOULD have at least 1 Locator
(i.e., L32 or LP) DNS resource record while it is connected to
the Internet. An ILNPv4-capable multi-homed host normally
will have multiple Locator values while multi-homed. An IP
host that is NOT ILNPv4-capable MUST NOT have an L32 or LP record
in its DNS entries. A node that is not currently connected to
the Internet might not have any L32 values in the DNS associated
with its owner name.
A DNS owner name that is naming a subnetwork, rather than naming
a host, MAY have an L32 record as a wild-card entry, thereby
applying to entries under that DNS owner name. This deployment
scenario probably is most common if the named subnetwork is, was,
or might become, mobile.
The type value for the L32 RR type is X-L32-X <to be assigned>.
The L32 RR is class independent.
The L32 RR has no special TTL requirements.
2.2.1 L32 RDATA Wire Format
The RDATA for an L32 RR consists of:
- a 16 bit Preference field
- a 32 bit Locator32 field
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Preference | Locator32 (16 MSBs) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Locator32 (16 LSBs) |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2.2.1.1 The Preference field
The <Preference> field is an unsigned 16-bit field in network
byte-order that indicates the owner name's relative preference
for this L32 record among other L32 records associated with this
owner name. Lower Preference values are preferred over higher
Preference values.
2.2.1.2 The Locator32 field
The <Locator32> field is an unsigned 32-bit integer in network
byte-order that is identical on-the-wire to the ADDRESS field
of the existing DNS A record.
2.2.2 L32 RR Presentation Format
The presentation of the format of the RDATA portion is as follows:
- The Preference field MUST be represented as a 16-bit unsigned
decimal integer.
- The Locator32 field MUST be represented using the same syntax
used for existing DNS A records (i.e. 4 decimal numbers
separated by periods without any embedded spaces).
2.2.3 L32 RR Examples
An L32 record has the following logical components:
<owner-name> IN L32 <Preference> <Locator32>
In the above <owner-name> is the owner name string, <Preference>
is an unsigned 16-bit value, and <Locator32> is an unsigned 32-bit
value.
host1.example.com. IN L32 10 10.1.02.0
host1.example.com. IN L32 20 10.1.04.0
host2.example.com. IN L32 10 10.1.08.0
As L32 values have the same syntax and semantics as IPv4 routing
prefixes, when displayed for human readership, the values are
presented in the same dotted-decimal format as IPv4 addresses.
An example of this syntax is shown above.
In the example above, the owner name is from a FQDN for an
individual host. host1.example.com has two L32 values, so
host1.example.com is multi-homed.
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Another example is when the owner name is that learned from an LP
record (see below for details of LP records).
l32-subnet1.example.com. IN L32 10 10.1.02.0
l32-subnet2.example.com. IN L32 20 10.1.04.0
l32-subnet3.example.com. IN L32 30 10.1.08.0
In this example above, the owner name is for a subnetwork rather
than an individual node.
2.2.4 Additional Section Processing
To improve performance, ILNP-aware DNS servers and DNS resolvers
MAY attempt to return all NID, L64, and LP records for the same
owner name of the L32 RRset in the Additional section of the
response, if space permits.
2.3 The L64 Resource Record
The L64 resource record (RR) is used to hold unsigned 64-bit
Locator Values for ILNPv6-capable nodes.
L64 records are present only for ILNPv6-capable nodes. This
restriction is important; ILNP-capable nodes use the presence of
L64 records in the DNS to learn that a correspondent node is also
ILNPv6-capable. While erroneous L64 records in the DNS for a
node that is not ILNP-capable would not prevent communication,
such erroneous DNS records could increase the delay at the start
of an IP session.
A given owner name might have zero or more L64 values at a given
time. An ILNPv6-capable host SHOULD have at least 1 Locator
(i.e., L64 or LP) DNS resource record while it is connected to
the Internet. An ILNPv6-capable multi-homed host normally
will have multiple Locator values while multi-homed. An IP
host that is NOT ILNPv6-capable MUST NOT have an L64 or LP record
in its DNS entries. A node that is not currently connected to
the Internet might not have any L64 values in the DNS associated
with its owner name.
A DNS owner name that is naming a subnetwork, rather than naming
a host, MAY have an L64 record as a wild-card entry, thereby
applying to entries under that DNS owner name. This deployment
scenario probably is most common if the named subnetwork is, was,
or might become, mobile.
The type value for the L64 RR type is X-L64-X <to be assigned>.
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The L64 RR is class independent.
The L64 RR has no special TTL requirements.
2.3.1 The L64 RDATA Wire Format
The RDATA for an L64 RR consists of:
- a 16 bit Preference field
- a 64 bit Locator64 field
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Preference | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +
| Locator64 |
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2.3.1.1 The Preference field
The <Preference> field is an unsigned 16-bit integer in network
byte-order that indicates the owner name's relative preference
for this L64 record among other L64 records associated with this
owner name. Lower Preference values are preferred over higher
Preference values.
2.3.1.2 The Locator64 field
The <Locator64> field is an unsigned 64-bit integer in network
byte-order that has the same syntax and semantics as a 64-bit
IPv6 routing prefix.
2.3.2 L64 RR Presentation Format
The presentation of the format of the RDATA portion is as follows:
- The Preference field MUST be represented as a 16-bit unsigned
decimal integer.
- The Locator64 field MUST be represented using the same syntax
used for AAAA records (i.e. groups of 4 hexadecimal digits
separated by colons). However, the 'compressed' display
format (e.g. using "::") that is specified in RFC-4291,
Section 2.2 (2), MUST NOT be used. This is done to avoid
confusion with a 128-bit IPv6 address, since the Locator64 is
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a 64-bit value, while the IPv6 address is a 128-bit value.
2.3.3 L64 RR Examples
An L64 record has the following logical components:
<owner-name> IN L64 <Preference> <Locator64>
In the above, <owner-name> is the owner name string, <Preference>
is an unsigned 16-bit value, while <Locator64> is an unsigned
64-bit value.
host1.example.com. IN L64 10 2001:0DB8:1140:1000
host1.example.com. IN L64 20 2001:0DB8:2140:2000
host2.example.com. IN L64 10 2001:0DB8:4140:4000
As L64 values have the same syntax and semantics as IPv6 routing
prefixes, when displayed for human readership, the values might
conveniently be presented in hexadecimal format, as above.
In the example above, the owner name is from a FQDN for an
individual host. host1.example.com has two L64 values, so it will
be multi-homed.
Another example is when the owner name is that learned from an LP
record (see below for details of LP records).
l64-subnet1.example.com. IN L64 10 2001:0DB8:1140:1000
l64-subnet2.example.com. IN L64 20 2001:0DB8:2140:2000
l64-subnet3.example.com. IN L64 30 2001:0DB8:4140:4000
Here, the owner name is for a subnetwork rather than an individual
node.
2.3.4 Additional Section Processing
To improve performance, ILNP-aware DNS servers and DNS resolvers
MAY attempt to return all NID, L32, and LP records for the same
owner name of the L64 RRset in the Additional section of the
response, if space permits.
2.4 The LP Resource Record
The LP DNS resource record (RR) is used to hold the name of a
subnetwork for ILNP. The name is an FQDN which can then be used
to look up L32 or L64 records. LP is, effectively, a Locator
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Pointer to L32 and/or L64 records.
As described in [ILNP-ARCH], the LP RR provides one level of
indirection within the DNS in naming a Locator value. This is
useful in several deployment scenarios, such as for a multi-homed
site where the multi-homing is handled entirely by the site's
border routers (e.g. via Locator rewriting) or in some mobile
network deployment scenarios [ILNP-ADV].
LP records MUST NOT be present for owner name values that are not
ILNP-capable nodes. This restriction is important; ILNP-capable
nodes use the presence of LP records in the DNS to infer that
a correspondent node is also ILNP-capable. While erroneous LP
records in the DNS for an owner name would not prevent
communication, presence of such erroneous DNS records could
increase the delay at the start of a IP session.
The type value for the LP RR type is X-LP-X <to be assigned>.
The LP RR is class independent.
The LP RR has no special TTL requirements.
2.4.1 LP RDATA Wire Format
The RDATA for an LPP RR consists of:
- an unsigned 16 bit Preference field
- a variable-length FQDN field
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Preference | /
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ /
/ /
/ FQDN /
/ /
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2.4.1.1 The Preference field
The <Preference> field contains an unsigned 16-bit integer in
network-byte order that indicates the owner name's relative
preference for this LP record among other LP records associated
with this owner name. Lower Preference values are preferred over
higher Preference values.
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2.4.1.2 The FQDN field
The variable-length FQDN field contains the DNS target name that
is used to reference L32 and/or L64 records. This field MUST NOT
have the same value as the owner name of the LP RR instance.
2.4.2 LP RR Presentation Format
The presentation of the format of the RDATA portion is as follows:
- The Preference field MUST be represented as a 16-bit unsigned
decimal integer.
- The FQDN field MUST be represented as a domain name.
The domain name MUST NOT be compressed.
2.4.3 LP RR Examples
An LP record has the following logical components:
<owner-name> IN LP <Preference> <FQDN>
In the above, <owner-name> is the owner name string, <Preference>
is an unsigned 16-bit value, while <FQDN> is the domain name
which should be resolved further.
host1.example.com. IN LP 10 l64-subnet1.example.com.
host1.example.com. IN LP 10 l64-subnet2.example.com.
host1.example.com. IN LP 20 l32-subnet1.example.com.
In the example above, host1.example.com is multi-homed on three
subnets. Resolving the FQDNs return in the LP records would
allow the actual subnet prefixes to be resolved, e.g. as in the
examples for the L32 and L64 RR descriptions, above. This level
of indirection allows the same L32 and/or L64 records to be used
by many hosts in the same subnetwork, easing management of the
ILNP network and potentially reducing the number of DNS Update
transactions, especially when that network is mobile [RAB09] or
multi-homed [ABH09a].
2.4.4 Additional Section Processing
To improve performance, ILNP-aware DNS servers and DNS resolvers
MAY attempt to return all L32 and L64 records for the same owner
name of the LP RRset in the Additional section of the response,
if space permits.
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3. DEPLOYMENT EXAMPLE
Given a domain name, one can use the Domain Name System (DNS) to
discover the set of NID records, the set of L32 records, the set
of L64 records, and the set of LP records that are associated
with that DNS owner name.
For example:
host1.example.com. IN NID 10 0014:4fff:ff20:ee64
host1.example.com. IN L64 10 2001:0DB8:1140:1000
would be the minimum requirement for an ILNPv6 node that has
owner name host1.example.com and is connected to the Internet at
the subnetwork having routing prefix 2001:0DB8:1140:1000.
If that host were multi-homed on two different IPv6 subnets:
host1.example.com. IN NID 10 0014:4fff:ff20:ee64
host1.example.com. IN L64 10 2001:0DB8:1140:1000
host1.example.com. IN L64 20 2001:0DB8:2140:2000
would indicate the Identifier and two subnets that
host1.example.com is attached to, along with the relative
preference that a client would use in selecting the
Locator value for use in initiating communication.
If host1.example.com were part of a mobile network,
a DNS query might return:
host1.example.com. IN NID 10 0014:4fff:ff20:ee64
host1.example.com. IN LP 10 mobile-net1.example.com.
and then a DNS query to find the current Locator value(s)
for the node named by the LP record:
mobile-net1.example.com. IN L64 2001:0DB8:8140:8000
3.1 Use of ILNP records
As these DNS records are only used with the Identifier-Locator
Network Protocol (ILNP), these records MUST NOT be present for a
node that does not support ILNP. This lookup process is
considered to be in the "forward" direction.
The Preference fields associated with the NID, L32, L64, and LP
records are used to indicate the owner name's preference for
others to use one particular NID, L32, L64, or LP record, rather
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than use another NID, L32, L64, or LP record also associated with
that owner name. Lower Preference field values are preferred
over higher Preference field values.
It is possible that a DNS stub resolver querying for one of these
record types will not receive all NID, L32, L64, and LP RR's in a
single response. Credible anecdotal reports indicate at least
one DNS recursive cache implementation actively drops all
Additional Data records that were not expected by that DNS
recursive cache. So even if the authoritative DNS server includes
all the relevant records in the Additional Data section of the
DNS response, the querying DNS stub resolver might not receive
all of those Additional Data records. DNS resolvers also might
purge some ILNP RRsets before others, for example if NID RRsets
have a longer DNS TTL value than Locator-related (e.g. LP, L32,
L64) RRsets. So a DNS stub resolver sending queries to a DNS
resolver cannot be certain if they have obtained all available
RRtypes for a given owner name. Therefore, the DNS stub resolver
SHOULD send follow-up DNS queries for RRTYPE values that were
missing and are desired, to ensure that the DNS stub resolver
receives all the necessary information.
Note nodes likely either to be mobile or to be multi-homed
normally will have very low DNS TTL values for L32 and L64
records, as those values might change frequently. However, the
DNS TTL values for NID and LP records normally will be higher,
as those values are not normally impacted by node location
changes. Previous trace-driven DNS simulations from MIT [JSBM02]
and more recent experimental validation of operational DNS from
U. of St Andrews [BA11] both indicate deployment and use of very
short DNS TTL values within 'stub' or 'leaf' DNS domains is not
problematic.
An ILNP node MAY use any NID value associated with its DNS owner
name with any or all Locator (L32 or L64) values also associated
with its DNS owner name.
3.2 Additional Section Processing
For all the records above, Additional Section Processing MAY be
used. This is intended to improve performance for both the DNS
client and the DNS server. For example, a node sending DNS query
for an NID owner name, such as host1.example.com, would benefit
from receiving all ILNP DNS records related to that owner name
being returned, as it is quite likely that the client will need
that information to initiate an ILNP session.
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However, this is not always the case: a DNS query for L64 for a
particular owner name might be made because the DNS TTL for a
previously resolved L64 RR has expired, while the NID RR for that
same owner name has a DNS TTL that has not expired.
4. SECURITY CONSIDERATIONS
These new DNS resource record types do not create any new
vulnerabilities in the Domain Name System.
Existing mechanisms for DNS Security can be used unchanged with
these record types [RFC4033] [RFC3007]. As of this writing, the
DNS Security mechanisms are believed to be widely implemented
in currently available DNS servers and DNS clients. Deployment
of DNS Security appears to be growing rapidly.
In situations where authentication of DNS data is a concern,
the DNS Security extensions SHOULD be used [RFC4033].
If these DNS records are updated dynamically over the network,
then the Secure Dynamic DNS Update [RFC3007] mechanism SHOULD be
used to secure such transactions.
5. IANA CONSIDERATIONS
IANA is requested to allocate each of these DNS Resource Records
NID
L32
L64
LP
(described above in Section 2) a Data RRTYPE value according to
the procedures of Section 3.1 and 3.1.1 on pages 7 through 9 of
RFC 6195 [RFC6195].
6. REFERENCES
6.1 Normative References
[RFC1034] P. Mockapetris, "Domain names - Concepts and
Facilities", RFC-1034, 1 November 1987
[RFC1035] P. Mockapetris, "Domain names - Implementation and
Specification", RFC-1035, 1 November 1987.
[RFC2119] Bradner, S., "Key words for use in RFCs to
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Indicate Requirement Levels", BCP 14, RFC 2119,
March 1997.
[RFC3007] B. Wellington, "Secure Domain Name System Dynamic
Update", RFC 3007, RFC Editor, November 2000.
[RFC3597] A. Gustafsson, "Handling of Unknown DNS Resource
Record (RR) Types", RFC 3597, September 2003.
[RFC4033] R. Arends, R. Austein, M. Larson, D. Massey, &
S. Rose, "DNS Security Introduction & Requirements",
RFC 4033, RFC Editor, March 2005.
[RFC6195] D. Eastlake 3rd, "Domain Name System IANA
Considerations", RFC 6195, March 2011.
[ILNP-ARCH] R.J. Atkinson & S.N. Bhatti,
"ILNP Architectural Description",
draft-irtf-rrg-ilnp-arch, 10 July 2012.
[ILNP-ENG] R.J. Atkinson & S.N. Bhatti,
"ILNP Engineering and Implementation Considerations",
draft-irtf-rrg-ilnp-eng, 10 July 2012.
6.2 INFORMATIVE REFERENCES
[ABH09a] R. Atkinson, S. Bhatti, & S. Hailes,
"Site-Controlled Secure Multi-Homing and Traffic
Engineering For IP", Procedings of IEEE Military
Communications Conference, IEEE, Boston, MA, USA.
Oct 2009.
[BA11] S. Bhatti & R. Atkinson, "Reducing DNS Caching",
Procedings of IEEE Global Internet Symposium (GI2011),
Shanghai, P.R. China. 15 Apr 2011.
<http://dx.doi.org/10.1109/INFCOMW.2011.5928919>
[JSBM02] J. Jung, E. Sit, H. Balakrishnan, and R. Morris,
DNS performance and the effectiveness of caching.
IEEE/ACM Trans. Netw. 10(5) (October 2002), 589-603.
<http://dx.doi.org/10.1109/TNET.2002.803905>
[PHG02] Andreas Pappas, Stephen Hailes, Raffaele Giaffreda,
"Mobile Host Location Tracking through DNS",
IEEE London Communications Symposium, London,
England, UK, September 2002.
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<http://www.ee.ucl.ac.uk/lcs/papers2002/LCS072.pdf>
[RAB09] D. Rehunthan, R. Atkinson, S. Bhatti,
"Enabling Mobile Networks Through Secure Naming",
Proceedings of IEEE Military Communications
Conference (MILCOM), IEEE, Boston, MA, USA,
Oct 2009.
[SB00] Alex C. Snoeren and Hari Balakrishnan. 2000.
"An End-To-End Approach To Host Mobility",
Proceedings of 6th Conference on Mobile Computing And
Networking (MobiCom), ACM, Boston, MA, USA,
August 2000.
[SBK01] Alex C. Snoeren, Hari Balakrishnan, & M. Frans
Kaashoek, "Reconsidering Internet Mobility",
Proceedings of 8th Workshop on Hot Topics in
Operating Systems (HotOS), IEEE Computer Society,
Elmau, Germany, May 2001.
[ILNP-ADV] R.J. Atkinson & S.N. Bhatti,
"Optional Advanced Deployment Scenarios for ILNP",
draft-irtf-rrg-ilnp-adv, 10 July 2012.
[ILNP-ARP] R.J. Atkinson & S.N. Bhatti, "ARP Extension for
ILNPv4", draft-irtf-rrg-ilnp-arp, 10 July 2012.
[ILNP-ICMPv4] R.J. Atkinson & S.N. Bhatti, "ICMPv4 Locator
Update message", draft-irtf-rrg-ilnp-icmpv4,
10 July 2012.
[ILNP-ICMPv6] R.J. Atkinson & S.N. Bhatti, "ICMPv6 Locator
Update message", draft-irtf-rrg-ilnp-icmpv6,
10 July 2012.
[ILNP-NONCEv6] R.J. Atkinson & S.N. Bhatti, "IPv6 Nonce
Destination Option for ILNPv6",
draft-irtf-rrg-ilnp-noncev6, 10 July 2012.
[ILNP-v4OPTS] R.J. Atkinson & S.N. Bhatti, "IPv4 Options for
ILNP", draft-irtf-rrg-ilnp-v4opts, 10 July 2012.
ACKNOWLEDGEMENTS
Steve Blake, Stephane Bortzmeyer, Mohamed Boucadair, Noel
Chiappa, Wes George, Steve Hailes, Joel Halpern, Mark Handley,
Volker Hilt, Paul Jakma, Dae-Young Kim, Tony Li, Yakov Rehkter,
Bruce Simpson, Robin Whittle and John Wroclawski (in alphabetical
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order) provided review and feedback on earlier versions of this
document. Steve Blake provided an especially thorough review of
an early version of the entire ILNP document set, which was
extremely helpful. We also wish to thank the anonymous reviewers
of the various ILNP papers for their feedback.
Roy Arends provided expert guidance on technical and procedural
aspects of DNS issues, for which the authors are greatly obliged.
RFC EDITOR NOTE
This section is to be removed prior to publication.
Please note that this document is written in British English, so
British English spelling is used throughout. This is consistent
with existing practice in several other RFCs, for example
RFC-5887.
This document tries to be very careful with history, in the
interest of correctly crediting ideas to their earliest
identifiable author(s). So in several places the first published
RFC about a topic is cited rather than the most recent published
RFC about that topic.
Authors' Addresses:
RJ Atkinson
Consultant
San Jose, CA
95125 USA
Email: rja.lists@gmail.com
SN Bhatti
School of Computer Science
University of St Andrews
North Haugh, St Andrews
Fife, Scotland, UK
KY16 9SX
Email: saleem@cs.st-andrews.ac.uk
Scott Rose
US National Institute for Standards & Technology
100 Bureau Drive
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Gaithersburg, MD
20899 USA
Email: scottr.nist@gmail.com
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[NOTE: Appendix A is to be removed by the
RFC Editor prior to publication.]
Appendix A:
DNS RRTYPE PARAMETER ALLOCATION TEMPLATE
When ready for formal consideration, this template is
to be submitted to IANA for processing by emailing the
template to dns-rrtype-applications@ietf.org.
A. Submission Date: To be determined.
B. Submission Type:
[X] New RRTYPE
C. Contact Information for submitter:
Name: R. Atkinson
Email Address: rja.lists@gmail.com
International telephone number: unlisted
Other contact handles:
D. Motivation for the new RRTYPE application?
Support for an experimental set of IP extensions
that replace the concept of an "IP Address" with
distinct "Locator" and "Identifier" values.
E. Description of the proposed RR type.
Please see:
http://tools.ietf.org/id/draft-irtf-rrg-ilnp-dns-03.txt
for a full description.
F. What existing RRTYPE or RRTYPEs come closest to filling
that need and why are they unsatisfactory?
There is no RRTYPE that fulfils the need due to the
new semantics of Locator and Identifier values.
The AAAA record combines both Locator and Identifier,
so has significantly different semantics than having
separate L64 and NID record values. The AAAA record also
lacks scalability and flexibility in the context of the
experimental protocol extensions that will use the NID
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and L64 records, as any valid NID record value for a node
can be used on the wire with any valid L64 record value
for the same node.
The CNAME record is closest conceptually to an LP
record, but a CNAME is a node name referral scheme,
while the LP record is indicating that the given node
has the same routing prefix as some other domain name,
but does not necessarily have any other values that are
the same.
Lastly, the AAAA and CNAME RR Types lack a Preference
field to rank responses. Such Preference information
is required for ILNP in order to support the use of multiple
instances of NID, L32, L64 and LP records.
G. What mnemonic is requested for the new RRTYPE (optional)?
As described in this draft, "NID", "L32", "L64", and "LP".
H. Does the requested RRTYPE make use of any existing IANA
Registry or require the creation of a new IANA
sub-registry in DNS Parameters?
Existing registry of DNS Resource Record (RR) data TYPE
values should be used.
I. Does the proposal require/expect any changes in DNS
servers/resolvers that prevent the new type from being
processed as an unknown RRTYPE (see [RFC3597]) ?
No.
J. Comments:
This document defines "ILNP-aware" DNS servers
or DNS resolver as a DNS server (authoritative or recursive)
that MAY include other ILNP RRTypes in the Additional
section of a DNS response that match a QNAME (if
size permits). This is to reduce the number of
DNS stub resolver follow-up DNS queries. and only applies
when the QTYPE is either NID, L32, L64, or LP. There is no
signalling mechanism for this Additional section
processing, and this is believed to be compatible
with existing non-ILNP-aware DNS servers and DNS stub
resolvers.
No changes are required for existing deployed
DNS servers or DNS resolvers.
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