INTERNET-DRAFT D. Meyer (Editor)
Category Informational
Expires: April 2004 October 2003
Routing Protocol Overloading --
Issues, Concerns, and Considerations
<draft-meyer-rpo-00.txt>
Status of this Document
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all provisions of Section 10 of RFC2026.
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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 [RFC 2119].
This document is a product of the RPO Design Team. Comments should
be addressed to the authors, or the mailing list at
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Copyright Notice
Copyright (C) The Internet Society (2003). All Rights Reserved.
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Abstract
The Routing Protocol Overloading (RPO) design team was formed to
document the concerns and considerations surrounding the use of
Internet routing protocols for functions not directly related to
routing of IP packets within the Internet and IP networks. This
document is the output of that activity.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 5
2. Scope of this Work . . . . . . . . . . . . . . . . . . . . . . 5
3. Problem Statement. . . . . . . . . . . . . . . . . . . . . . . 6
3.1. Risk, Interference, and Application Fit . . . . . . . . . . 6
3.1.1. Risk: Software Engineering . . . . . . . . . . . . . . . 7
3.1.2. Interference: Protocol Specification/Dynamic Behavior . 7
3.1.3. Application Fit. . . . . . . . . . . . . . . . . . . . . 7
4. Definitions. . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.1. Layer 3 Routing Information . . . . . . . . . . . . . . . . 8
4.2. Reachability Information. . . . . . . . . . . . . . . . . . 8
4.3. Auxiliary (non-routing) Information . . . . . . . . . . . . 8
4.4. Address Family Identifier (AFI) . . . . . . . . . . . . . . 9
4.5. Subsequent Address Family Identifier (SAFI) . . . . . . . . 9
4.6. Network Layer Reachability. . . . . . . . . . . . . . . . . 9
4.7. Application . . . . . . . . . . . . . . . . . . . . . . . . 10
4.8. Routing Protocol. . . . . . . . . . . . . . . . . . . . . . 10
4.9. Fate Sharing. . . . . . . . . . . . . . . . . . . . . . . . 10
5. Architectural Models . . . . . . . . . . . . . . . . . . . . . 10
5.1. General Purpose Transport Infrastructure (GPT) Model. . . . 11
5.2. Special Purpose Transport Infrastructure (SPT) Model. . . . 11
6. Analyzing Risk and Interference. . . . . . . . . . . . . . . . 12
6.1. Risk: Code Impact, and Resource Sharing . . . . . . . . . . 12
6.1.1. Code Impact. . . . . . . . . . . . . . . . . . . . . . . 13
6.1.2. Resource Sharing . . . . . . . . . . . . . . . . . . . . 13
6.1.2.1. Resource Sharing and Operating System Level Issues . 14
6.2. Interference. . . . . . . . . . . . . . . . . . . . . . . . 14
7. BGP and TCP Models: Risk and Interference. . . . . . . . . . . 15
7.1. Risk. . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
7.1.1. Code Impact. . . . . . . . . . . . . . . . . . . . . . . 15
7.1.2. Resource Sharing . . . . . . . . . . . . . . . . . . . . 16
7.2. Interference. . . . . . . . . . . . . . . . . . . . . . . . 17
7.3. The TCP Model and Interference. . . . . . . . . . . . . . . 17
7.4. The BGP Model and Interference. . . . . . . . . . . . . . . 18
8. Operational Implications . . . . . . . . . . . . . . . . . . . 18
9. Conclusions and Recommendations. . . . . . . . . . . . . . . . 18
10. Intellectual Property . . . . . . . . . . . . . . . . . . . . 18
11. Design Team . . . . . . . . . . . . . . . . . . . . . . . . . 18
12. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 19
13. Security Considerations . . . . . . . . . . . . . . . . . . . 20
14. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 20
15. References. . . . . . . . . . . . . . . . . . . . . . . . . . 21
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15.1. Normative References . . . . . . . . . . . . . . . . . . . 21
15.2. Informative References . . . . . . . . . . . . . . . . . . 23
16. Editor's Address. . . . . . . . . . . . . . . . . . . . . . . 24
17. Full Copyright Statement. . . . . . . . . . . . . . . . . . . 24
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1. Introduction
The stability of the global Internet routing system has been the
subject of much research (see e.g., [RVBIB]) and discussion on
various IETF mailing lists [IETFOL]. Much of the research into the
routing system has centered around the analysis of the dynamics and
stability of the Border Gateway Protocol Version 4 [BGP] (hereafter
referred to as BGP).
However, while the theoretical properties of BGP remains a topic of
great interest, a more recent discussion has focused on effects of
the addition of new types of Network Layer Reachability Information,
or NLRI to BGP. In particular, the advent of two BGP attributes,
Multiprotocol Reachable NLRI (MP_REACH_NLRI), and Multiprotocol
Unreachable NLRI (MP_UNREACH_NLRI) [RFC2858], have made it possible
to encode and transport a wide variety of features and their
associated signaling using the BGP transport infrastructure. Examples
include IPv6 [RFC2460], flow specification rules [FLOW], virtual
private LAN services [VPLS], and virtual private Wire Service [VPWS].
Finally, while this document outlines the concerns and issues
surrounding using the BGP infrastructure as a generic feature and
signaling transport, note that the similar concerns apply to the
Interior Gateway Protocols (IGPs) in common use (e.g., ISIS [RFC1142]
or OSPF [RFC2328]), although at this time there is no specific
material on IGPs.
The rest of this document is organized as follows: Section 2 outlines
the scope of this work. Section 3 introduces the problem statement
which is the focus of this document, section 4 provides definitions,
and section 5 outlines the main architectural models that are
discussed. The remaining sections discuss the the implications of
those models.
2. Scope of this Work
It is the intention of the RPO design team that this document serve
as a guide for both protocol designers and network operators, and
that an attempt is being made to shine a neutral light on the
implications (in the form of both benefits and offshoots) associated
with proceeding to employ routing protocols to enable additional
feature sets and functionality, or to design new mechanisms for
carriage of that information.
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The issues, concerns and considerations discussed in this document
focus on the implications for BGP [BGP,RFC1771]. It is important to
note that similar issues will arise when considering generalizations
to the information that the IGPs carry.
3. Problem Statement
The advent of the MP_REACH_NLRI and MP_UNREACH_NLRI attributes,
combined with the resulting generalization to the BGP infrastructure,
have created the opportunity to use BGP to transport a wide variety
of data types and their associated signaling. The combination of a
BGP data type and its associated signaling is frequently called an
"application"; example applications include the IPv4 routing system,
flow specification rules [FLOW], auto-discovery mechanisms for Layer
3 VPNs [BGPVPN], and virtual private LAN services [VPLS].
More recently, the discussion in the IETF community has focused on
the use of the BGP as a generalized feature transport infrastructure
[IETFOL]. The debate has recently intensified due to the emergence of
a new class of application that use the BGP infrastructure to
distribute information that is not directly related to inter-domain
routing. Examples of such applications include the use of the BGP
transport infrastructure to provide auto-discovery for Layer 3 VPNs
[BGPVPN] and the virtual private LAN services mentioned above.
3.1. Risk, Interference, and Application Fit
As mentioned above, much of the debate surrounding these new uses of
BGP transport infrastructure has focused on the potential tradeoffs
between the stability of the Internet routing system as effected by
the deployment of new applications, and the desire on the part of
service providers to rapidly deploy these new applications. These
tradeoffs have at times been described in terms of risk,
interference, and application fit. Risk models the software
engineering impact of new applications on a generic implementation,
while interference models the impact of new applications on protocol
definition and behavior. Finally, application fit models the
similarity between application's data and signaling requirements and
a specific distribution algorithm. Each is described below.
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3.1.1. Risk: Software Engineering
Risk attempts to assess the robustness tradeoffs inherent in the
addition of new applications to a given implementation. In this case,
risk models the impact of generic software engineering issues on a
given implementation. These issues including the impact of new
applications on existing implementations and on the fate sharing
properties of those implementations.
A second aspect of risk lies in the trade-off of extending an
existing protocol (with the risks in 3.1.1), versus designing,
implementing, and deploying a new protocol. (more from Kireeti here).
3.1.2. Interference: Protocol Specification/Dynamic Behavior
Interference, on the other hand, models the potential for a new
application to adversely effect the operation of an existing
implementation, at the protocol level, by inadvertently introducing a
detrimental dependency of some kind. That is, is it possible that we
might, by some extension, break something fundamental to a protocol's
specification? For example, could we create a new state which
introduces an unanticipated deadlock situation to occur? Or could we
destabilize the distributed behavior of the protocol? Or might we
simply run out of the attributes or bits available (as happened, for
example, with RADIUS [RFC2138])?
3.1.3. Application Fit
Application fit refers to the matching of the requirements of the
data to be distributed with the underlying capabilities of a
distribution mechanism. Broadcast, multicast and unicast
distribution mechanisms in use today. When considering a
distribution mechanism (such as BGP), an important issue to address
is whether the behavior of the distribution mechanism matches the
distribution needs. For example, it is clearly inefficient to
broadcast data to all peers that is only required between two peers,
just as it is inefficient to create many unicasts of data that is
required by all peers when a single broadcast would do.
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4. Definitions
4.1. Layer 3 Routing Information
Layer 3 routing information represents either link state information
or network reachability information. Link state information
represents Layer 3 adjacencies and topology. Link state routing
protocols, such as OSPF [RFC2328] and ISIS [RFC1142], flood link
state information throughout an IGP domain, so that each
participating router maintains an identical copy of a database that
is computed to reflect the complete Layer 3 topology.
Layer 3 reachability information represents Layer 3 networks that are
reachable through gateway routers. Distance/path vector routing
protocols, such as BGP, distribute Layer 3 reachability information
among routing domains.
Routers use both types of Layer 3 routing information (link state and
reachability) to produce IP forwarding tables.
For purposes of this discussion, "routing information" relates to the
Layer 3 inter-domain routing data traditionally carried by BGP.
4.2. Reachability Information
Reachability information refers to information describing some locale
of a network, along with how one can reach it, and perhaps also
containing attributes that indicate the suitability of the implied |
path to the network locale. An example is VPLS information [VPLS].
4.3. Auxiliary (non-routing) Information
Auxiliary Information is any information that is exchanged by routers
which is neither Layer 3 routing information, nor reachability
information. For example, flow specification [FLOW] is auxiliary
information.
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4.4. Address Family Identifier (AFI)
An Address Family contains addresses that share common structure and
semantics. An Address Family Identifier (AFI) uniquely identifies
each address family. Several routing protocol messages contain a
field that represents the AFI. The AFI identifies the address type
used by another data item contained in that message. The Routing
Information Protocol (RIP) [RFC2453], Distance Vector Multicast
Routing Protocol (DVMRP) [RFC1075], and BGP all employ the AFI field.
For example, the BGP MP_REACH_NLRI and MP_UNREACH_NLRI attributes
contain an AFI field. These BGP attributes also contain a NLRI field
that enumerates reachable or unreachable subnetworks corresponding to
the associated address family. The AFI field indicates the address
type by which reachable subnetworks are identified. When BGP is used
to distribute Layer 3 routing information, AFIs can indicate the
following address types: IPv4, IPv6, VPNv4 [RFC2547BIS]. When BGP is
used to distribute auxiliary information, AFIs can indicate other
address families.
4.5. Subsequent Address Family Identifier (SAFI)
A Subsequent Address Family Identifier (SAFI) is part of the BGP
MP_REACH_NLRI and MP_UNREACH_NLRI attributes. These BGP attributes
also contain a NLRI field that enumerates reachable or unreachable
subnetworks. The SAFI augments the AFI, carrying additional
information regarding networks enumerated in the NLRI field.
4.6. Network Layer Reachability
Network Layer Reachability Information, or NLRI is the data described
by the AFI/SAFI fields [AFI,SAFI]. While these concepts were
originally described for protocols such as DVMRP [RFC1075], the bulk
of the generalization of the NLRI described in this document derive
from the introduction to BGP of the MP_REACH_NLRI and MP_UNREACH_NLRI
attributes [RFC2858].
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4.7. Application
The term application is used in this document to refer to the
combination of a BGP data type and any signaling data that is carried
by BGP in support of the service the data type carries. The data type
is typically described an AFI/SAFI, while the actual data is
frequently contained in both NLRI and BGP community attributes
[RFC1997].
4.8. Routing Protocol
A routing protocol is composed of two basic components: a data
distribution algorithm and a decision algorithm. A router typically
obtains Layer 3 routing information via its data distribution
algorithm, and it uses this information to produce an IP forwarding
table (by applying the protocol's decision algorithm to the received
routing data). Note that it is the use of BGP's data distribution
algorithm that is the focus of this document. However, when judging
application fit, one may also consider whether the decision
algorithms suit the application.
4.9. Fate Sharing
The fate sharing principle for end to end network protocols was first
enunciated by Dave Clark [CLARK]. As applied to software systems,
fate sharing refers to the sharing of common resources among a group
of applications. In our case, the particular "fate" of most interest
is the ability of one application, call it application A, to cause an
application with which it is fate sharing, call it application B, to
experience one or more faults due to faults in application A. In the
case of BGP, one way to reduce fate sharing is to run applications A
and B in seprate BGP sessions.
5. Architectural Models
In this section, we consider the two architectural models which are
motivated by salient questions considered in this document, namely:
Does the BGP distribution protocol suit a particular
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application, and if it does, what are the effects on the global
routing system (if any) of carrying that application using the
BGP distribution protocol?
That is:
(i). Does the BGP distribution protocol suit a particular application?
(ii). What are the effects on the global routing system (if
any) of carrying that application using the BGP
distribution protocol?
These questions must be analyzed in terms of the the cost of protocol
and code development, as well as operational expense that may be
incurred by utilizing (or not utilizing) the mechanisms already
present in BGP.
Two models, describing alternate viewpoints, are examined in the
following sections.
5.1. General Purpose Transport Infrastructure (GPT) Model
The GPT model models BGP data distribution infrastructure as a
generic application transport mechanism. As such, it focuses on
"application fit", and assumes that the tradeoffs, both in terms of
risk and interference can be managed in an efficient manner. As a
result, the GTP models these issues not in terms of whether the
application and signaling data that need to be distributed are part
of some particular class (routing, in this case), but rather whether
the requirements for the distribution these attributes are similar
enough to the distribution mechanisms of BGP. In those cases when
they are sufficiently similar, BGP becomes a logical candidate for
such a transport infrastructure. Note that this is not because of the
nature of information distributed, but rather due to the similarity
in the transport requirements. There are other operational
considerations that make BGP a logical candidate, including its close
to ubiquitous deployment in the Internet (as well as in intra-nets),
its policy capabilities, and operator comfort levels with the
technology.
5.2. Special Purpose Transport Infrastructure (SPT) Model
The SPT model, on the other hand, models the BGP infrastructure as a
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special purpose transport designed specifically to transport inter-
domain routing information. As such, it is more sensitive to risk and
interference than to application fit.
There are two basic arguments supporting the SPT model: The first is
based on the perceived risk profile of the fate sharing involved in
adding new applications to the BGP transport infrastructure. The
concern here is that the new applications being added to BGP will
cause software quality degrade, and hence destabilize the global
routing system. This position is based upon well understood software
engineering principles, and is strengthened long-standing experience
that there is a direct correlation between software features and bugs
[MULLER1999]. This concern is augmented by the fact that in many
cases, the existence of the code for these features, even if unused,
can also cause destabilization in the routing system, since in many
cases software faults cannot be isolated.
A second concern is based on interference arguments, notably that the
increase in complexity of BGP due to the number of data types that it
carries can also potentially destabilize the global routing system.
This concern is based on a wide range of concerns, including that the
interaction of BGP dynamics and current deployment practices are
poorly understood, and that the addition of non-routing data types
may adversely effect convergence and other scaling properties of the
global routing system.
6. Analyzing Risk and Interference
One way to frame the tradeoffs involved in analyzing risk is in terms
of the software engineering issues surrounding where an
implementation might demultiplex among applications. An
implementation's application demultiplexing point directly effects a
given implementation's risk profile due to its effects on existing
code, and on the system resources it requires to be shared among
those applications.
6.1. Risk: Code Impact, and Resource Sharing
For purposes of this discussion, we consider two models of
application demultiplexing: The first model, which we will call the
"BGP model", based on the current BGP model, provides a single point
for demultiplexing all applications (i.e., the AFI/SAFI). The BGP
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model is and instantiation of the GPT model.
The second model, which we will call the "TCP model", provides an
application demultiplexing point above BGP (typically at the TCP port
level). In particular, in the BGP model, applications currently share
a common transport session, while the TCP model envisions one or more
applications per transport session. The TCP model an instantiation of
the SPT model.
Finally, note that these models can have very risk profiles with
respect to code impact and resource sharing. Some of the questions
relating to risk assessment are considered below.
6.1.1. Code Impact
In this section, we outline the high-level questions one might ask in
assessing the difference in risk between TCP model and the BGP model
based on their effect on an existing code base.
o Does the code below the demultiplexing point need to be
changed when a new application is added?
o Does the code in existing applications have to be changed when
a new application is added (that is, to what extent are the
applications decoupled)?
o Can the code in separate applications be developed, tested,
released, debugged and packaged independently from other
applications?
o Is there significant code below the demultiplexing point that
can be shared among all applications?
6.1.2. Resource Sharing
In this section, we outline the high-level questions one might ask in
assessing the difference in risk between TCP model and the BGP model
with respect to the requirements and properties of the system
resource sharing it they require.
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o Do applications have to compete for socket buffers, and hence
have to potential to block or starve each other (at the TCP
port level)?
o Do applications have to compete for possible protocol-level
transport-related buffers and queues, and hence have the
potential to starve or block each other at the protocol
send/receive level?
o Do applications have to compete for a possible per-connection
processing time budget, hence have the potential to starve
each other at the intra-process scheduling level?
o Do applications have to compete for resources within the
network (e.g., bandwidth), when the protocol session spans
multiple hops ?
6.1.2.1. Resource Sharing and Operating System Level Issues
In this section, we outline the high-level questions one might ask in
assessing the difference in risk between TCP model and the BGP model
based on the effect on resource sharing at the operating system
level.
o Do applications share a common scheduling context? That is,
do applications have to compete for per-process scheduling
budgets?
o What is the degree of fate sharing between applications?
6.2. Interference
Interference models the potential for a new application to effect the
behavior of an existing application or applications. For example, in
the case of the Internet routing system, one might ask if a certain
application "interferes" with IPv4 Unicast routing by effecting some
aspect of its protocol operation (e.g., convergence time).
Interference in the Internet routing system has it is roots in the
observation that the routing system itself can be described as highly
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self-dissimilar, with extremely different scales and levels of
abstraction. Complex systems with this property are susceptible
"coupling", which RFC 3439 [RFC3439] defines as follows:
The Coupling Principle states that as things get larger, they
often exhibit increased interdependence between components.
COROLLARY: The more events that simultaneously occur, the
larger the likelihood that two or more will interact. This
phenomenon has also been termed "unforeseen feature
interaction" [WILLINGER2002].
That is, interference, if and where it occurs, has its roots protocol
complexity and is frequently the result of application coupling.
7. BGP and TCP Models: Risk and Interference
In this section, we analyze the BGP and TCP models risk and
interference.
7.1. Risk
As mentioned above, risk models the robustness tradeoffs around
generic software architecture and engineering associated with
protocol implementations, including the impact on impact on existing
protocol implementations, and on the fate sharing properties of those
implementations. In the following sections we consider these
components of risk for both the TCP and BGP models.
7.1.1. Code Impact
In this section, we outline the answers to the questions posed above.
o Does the code below the demultiplexing point need to be
changed when a new application is added?
Such code changes are unlikely to be required in the TCP model,
as the TCP model envisions that a new application will have a
new demultiplexing point (port).
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In theory, the BGP model does not require new code below the
demultiplexing point either. Specifically, it is possible
to isolate code below the demultiplexing point with suitable
abstraction and constructs such as AFI/SAFI API registries.
o Does the code in existing applications have to be changed when
a new application is added (that is, to what extent are the
applications decoupled)?
The TCP model envisions application independence with respect
to demultiplexing point. As such, it is unlikely to require
such changes. However, it is important to note that good
software engineering practices encourage code reuse and
construction of general purpose libraries. As a result, if
applications share libraries and/or other code, the practical
independence decreases, and consequently risk increases. The
same analysis can be made for the BGP model, since in this case
we are already demultiplexing on the AFI/SAFI fields.
o Can the code in separate applications be developed, tested,
released, debugged and packaged independently from other
applications?
While this is theoretically possible in the TCP model (and
possibly harder in the BGP model) practice and experience has
shown that achieving this type of independence is difficult in
either model.
7.1.2. Resource Sharing
In this section, we address the questions raised above to assess the
difference in risk between TCP model and the BGP model based on the
effect on resource sharing considerations.
o Do applications have to compete for socket buffers, and hence
have to potential to block or starve each other (at the TCP
level)?
The TCP model does not require applications to compete for
socket level resources. It should also be possible to achieve
this type of application independence in the BGP model with
multi-session extensions to BGP (i.e., grouping of one or more
AFI/SAFI per TCP session).
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o Do applications have to compete for possible protocol-level
transport-related buffers and queues, and hence have the
potential to starve or block each other at the protocol
send/receive level?
Again, while the TCP model does not require competition for
transport-level resources, it should be possible to achieve
similar behavior with the BGP model and multi-session
extensions.
o Do applications have to compete for a possible per-connection
processing time budget, hence have the potential to starve
each other at the intra-process scheduling level?
Applications written to the the TCP model should require this
type of resource competition. Note, however, that it should be
possible in the BGP model with multi-session extensions to
BGP.
o Do applications have to compete for resources within the
network (e.g., bandwidth), when the protocol session spans
multiple hops ?
Neither the TCP model nor the BGP model (again, with
multi-session extensions) should be require competition for
network resources in this case.
7.2. Interference
Interference concerns stem from the possibility that application
coupling can lead to the destabilization of the Internet routing
system in unanticipated and unexpected ways. In this section we
consider interference properties of the TCP and BGP models.
7.3. The TCP Model and Interference
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7.4. The BGP Model and Interference
8. Operational Implications
9. Conclusions and Recommendations
10. Intellectual Property
The IETF takes no position regarding the validity or scope of any
intellectual property or other rights that might be claimed to
pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights
might or might not be available; neither does it represent that it
has made any effort to identify any such rights. Information on the
IETF's procedures with respect to rights in standards-track and
standards-related documentation can be found in BCP-11 [RFC2028].
Copies of claims of rights made available for publication and any
assurances of licenses to be made available, or the result of an
attempt made to obtain a general license or permission for the use of
such proprietary rights by implementors or users of this
specification can be obtained from the IETF Secretariat.
The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary
rights which may cover technology that may be required to practice
this standard. Please address the information to the IETF Executive
Director.
11. Design Team
The design team that produced this document consisted of Daniel
Awduche (awduche@awduche.com), Ron Bonica (Ronald.P.Bonica@mci.com),
Hank Kilmer (hank@rem.com), Kireeti Kompella (kireeti@juniper.net),
Chris Lewis (chrlewis@cisco.com), Danny McPherson (danny@tcb.net),
David Meyer (dmm@1-4-5.net) and Pete Whiting (pete@sprint.net).
Meyer, et. al. Section 11. [Page 18]
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12. Acknowledgments
David Ball, Eric Rosen, and Mark Townsley made many insightful
comments on earlier versions of this draft.
Meyer, et. al. Section 12. [Page 19]
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13. Security Considerations
This document specifies neither a protocol nor an operational
practice, and as such, it creates no new security considerations.
14. IANA Considerations
This document creates a no new requirements on IANA namespaces
[RFC2434].
Meyer, et. al. Section 14. [Page 20]
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15. References
15.1. Normative References
[AFI] http://www.iana.org/assignments/address-family-
numbers
[BGP] Rekhter, Y, T.Li, and S. Hares, "A Border Gateway
Protocol 4 (BGP-4)", draft-ietf-idr-bgp4-20.txt,
Work in Progress.
[BGPVPN] Ould-Brahim, H., E. Rosen, and Y. Rekhter, "Using
BGP as an Auto-Discovery Mechanism for
Provider-provisioned VPNs",
draft-ietf-l3vpn-bgpvpn-auto-00.txt, July,
2003. Work in Progress.
[CLARK] Clark, D., "Design Philosophy of the DARPA Internet
Protocols", Computer Communication Review, volume
25, number 1, January 1995. ISSN # 0146-4833.
[EXTCOMM] Sangali, S., D. Tappan, and Y. Rekhter, "BGP
Extended Communities Attribute",
draft-ietf-idr-bgp-ext-communities-06.txt. Work
in Progress.
[FLOW] Marques, P, et. al., "Dissemination of flow
specification rules",
draft-marques-idr-flow-spec-00.txt, June,
2003. Work in Progress.
[MULLER1999] Muller, R. et. al., "Control System Reliability
Requires Careful Software Installation
Procedures", International Conference on
Accelerator and Largeand Large Experimental
Physics Systems, 1999, Trieste, Italy.
[RFC1075] Waitzman, D., C. Partridge, and S. Deering,
"Distance Vector Multicast Routing Protocol", RFC
1075, November, 1988.
[RFC1142] Oran, D. Editor, "OSI IS-IS Intra-domain Routing
Protocol", RFC 1142, February, 1990.
[RFC1771] Rekhter, Y., and T. Li, "A Border Gateway
Protocol 4 (BGP-4)", RFC 1771, March 1995.
Meyer, et. al. Section 15.1. [Page 21]
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[RFC1958] Carpenter, B., "Architectural principles of the
Internet", Editor. RFC 1958, June 1996.
[RFC1997] Chandra, R., P. Traina, and T. Li, "BGP
Communities Attribute", RFC 1997, August, 1996.
[RFC2138] Rigney, C., et. al., "Remote Authentication Dial
In User Service (RADIUS)", RFC 2138, April, 1997.
[RFC2328] Moy, J., "OSPF Version 2", RFC 2328, April, 1998.
[RFC2453] Malkin, G., "RIP Version 2", RFC 2453, November,
1998.
[RFC2460] Deering, S. and R. Hinden, "Internet Protocol,
Version 6 (IPv6) Specification", RFC 2460,
December, 1998.
[RFC2547BIS] Rosen, E., et. al., "BGP/MPLS IP VPNs",
draft-ietf-l3vpn-rfc2547bis-00.txt, May, 2003,
Work in Progress.
[RFC2858] Bates, T., et. al., "Multiprotocol Extensions
for BGP-4", RFC 2858, June 2000.
[RFC3439] Bush, R. and D. Meyer, "Some Internet
Architectural Guidelines and Philosophy", RFC
3439, December, 2002.
[SAFI] http://www.iana.org/assignments/safi-namespace
[VLPS] Kompella, K., et. al. "Virtual Private LAN
Service", draft-ietf-l2vpn-vpls-bgp-00.txt,
Work in Progress.
[VPWS] Kompella, K. et.al. "Layer 2 VPNs Over Tunnels",
draft-kompella-ppvpn-l2vpn-03.txt, April
2003. Work in Progress.
Meyer, et. al. Section 15.1. [Page 22]
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15.2. Informative References
[IETFOL] https://www1.ietf.org/mailman/listinfo/routing-discussion
[RFC2119] Bradner, S., "Key words for use in RFCs to
Indicate Requirement Levels", RFC 2119, March,
1997.
[RFC2026] Bradner, S., "The Internet Standards Process --
Revision 3", RFC 2026/BCP 9, October, 1996.
[RFC2028] Hovey, R. and S. Bradner, "The Organizations
Involved in the IETF Standards Process", RFC
2028/BCP 11, October, 1996.
[RFC2434] Narten, T., and H. Alvestrand, "Guidelines for
Writing an IANA Considerations Section in RFCs",
RFC 2434/BCP 26, October 1998.
[RVBIB] http://www.routeviews.org/papers
[WILLINGER2002] Willinger, W., and J. Doyle, "Robustness and the
Internet: Design and evolution", 2002.
Meyer, et. al. Section 15.2. [Page 23]
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16. Editor's Address
David Meyer
Email: dmm@1-4-5.net
17. Full Copyright Statement
Copyright (C) The Internet Society (2003). All Rights Reserved.
This document and translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain it
or assist in its implementation may be prepared, copied, published
and distributed, in whole or in part, without restriction of any
kind, provided that the above copyright notice and this paragraph are
included on all such copies and derivative works. However, this
document itself may not be modified in any way, such as by removing
the copyright notice or references to the Internet Society or other
Internet organizations, except as needed for the purpose of
developing Internet standards in which case the procedures for
copyrights defined in the Internet Standards process must be
followed, or as required to translate it into languages other than
English.
The limited permissions granted above are perpetual and will not be
revoked by the Internet Society or its successors or assigns.
This document and the information contained herein is provided on an
"AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Meyer, et. al. Section 17. [Page 24]