Dynamic Softwire Configuration of MAP-T and MAP-E Prefix Parameters via BGP
draft-bgp-softwire-map-prefix-communities-00
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| Document | Type | Active Internet-Draft (individual) | |
|---|---|---|---|
| Authors | Moshiko Nayman , Avinash Reddy Lingala | ||
| Last updated | 2024-08-16 | ||
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| Intended RFC status | (None) | ||
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draft-bgp-softwire-map-prefix-communities-00
Network Working Group M. Nayman, Ed.
Internet-Draft Juniper Networks
Intended status: Standards Track R. Lingala
Expires: 17 February 2025 AT&T
August 2024
Dynamic Softwire Configuration of MAP-T and MAP-E Prefix Parameters via
BGP
draft-bgp-softwire-map-prefix-communities-00
Abstract
This document proposes an OPTIONAL extension to the current MAP-T
(Mapping of Address and Port using Translation) [RFC7599] and MAP-E
(Mapping of Address and Port with Encapsulation) [RFC7597]
configuration mechanisms. It allows for dynamically learned and
programmed MAP-T or MAP-E prefix value parameters via BGP-learned
prefixes marked with extended community attributes, enabling a more
flexible and scalable approach compared to static configuration.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on 2 February 2025.
Copyright Notice
Copyright (c) 2024 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/
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Please review these documents carefully, as they describe your rights
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extracted from this document must include Revised BSD License text as
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provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 2
1.2. Overview . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Security Considerations . . . . . . . . . . . . . . . . . . . 4
3. References . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.1. Normative References . . . . . . . . . . . . . . . . . . 5
3.2. Informative References . . . . . . . . . . . . . . . . . 5
Appendix A. Acronyms and Abbreviations . . . . . . . . . . . . . 6
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 6
Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7
1. Introduction
MAP-T and MAP-E are mechanisms that enable the transition from IPv4
to IPv6 by mapping IPv4 addresses and ports to IPv6 addresses (RFC
7599 and RFC 7597 respectively).
The current standard requires static configuration of MAP-T and MAP-E
prefix parameters, which can be cumbersome and inflexible in large-
scale networks. This document proposes a method to dynamically
configure MAP-T and MAP-E parameters using BGP-learned prefixes with
extended community attributes, enhancing the efficiency and
adaptability of network configurations.
1.1. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] when, and only when, they appear in all capitals, as
shown here.
1.2. Overview
The proposed solution introduces dynamic MAP-T and MAP-E softwire
prefixes parameter configuration using BGP-learned prefixes. This
approach allows for the dynamic assignment of MAP-T and MAP-E domain-
specific parameters, such as the DMR prefix, IPv4 prefix, and MAP-T/
MAP-E prefix, based on BGP updates.
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This initiative leverages the framework established in [RFC7153] for
defining new BGP communities. The new BGP communities are required
to indicate where the prefix will be imported and dynamically
configured. By associating these communities with specific MAP-T and
MAP-E parameters, the BGP updates can precisely control the
importation and configuration of these prefixes within the network.
This ensures that the dynamic parameters are applied accurately and
efficiently, allowing for real-time adaptability to network changes.
To facilitate this dynamic configuration, new BGP softwire
extended communities will be defined. These communities will be
associated with specific softwire concentrators and prefixes:
- dmr:{number}:{prefix}
- ipv4:{number}:{prefix}
- map:{number}:{prefix}
The community attribute *dmr* refers to the DMR prefix (Softwire DMR
IPv6 Address). The community attribute ipv4 refers to the MAP-T/
MAP-E domain's rule IPv4 prefix/length.
The community attribute *map* refers to the MAP-T/MAP-E domain's rule
IPv6 prefix/length.
The {number} refers to the name or number or term of the MAP-T/MAP-E
softwire concentrator. Since a MAP-T BR can have multiple MAP-T
domains with different prefixes, this helps identify where the prefix
will be associated. The {prefix} refers to the actual MAP-T or MAP-E
prefix.
These extended community attributes are associated with the
following Address Family Identifier (AFI) and Subsequent Address
Family Identifier (SAFI) combinations as specified in IANA and
described in [RFC2858] and [RFC4760].
- IPv4 Unicast (AFI: 1, SAFI: 1)
- IPv6 Unicast (AFI: 2, SAFI: 1)
- VPNv4 Unicast (AFI: 1, SAFI: 128)
- VPNv6 Unicast (AFI: 2, SAFI: 128)
Behavior and Route Resolution:
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- Route with only one or more softwire communities (e.g.,
dmr:{number}:{prefix}, ipv4:{number}:{prefix}, or
map:{number}:{prefix}): The route will be accepted with a maximum
metric and will not be installed in the forwarding table.
- Route with Other Communities: The route will be processed
according to the standard BGP policy or the specific policy
defined by the user.
- Softwire communities: This community MUST also act as a
NO_ADVERTISE (0xFFFFFF02) attribute well-known as defined in
[RFC8642] unless a user-defined policy specifies otherwise.
This initiative is OPTIONAL for MAP-T and MAP-E; it is not necessary
for them to function. It provides an optional mechanism to enhance
the configuration process.
Users can take advantage of BGP-advertised MAP-T and MAP-E parameters
by leveraging the newly defined BGP extended communities to
dynamically update their configurations. When a BGP route containing
one of the specified extended communities (e.g.,
dmr:{number}:{prefix}, ipv4:{number}:{prefix}, or
map:{number}:{prefix}) is received, the router can automatically
parse these communities and update the MAP-T/MAP-E configuration
accordingly. This approach ensures that the configuration is always
up-to-date with the latest network changes, reduces administrative
overhead, and enhances scalability by allowing centralized management
of MAP-T and MAP-E parameters through BGP.
The new softwire extended community attributes defined in this
document are **Transitive Extended Communities**. This designation is
essential because MAP-T and MAP-E parameters need to be propagated
across different BGP sessions, ensuring that routers throughout the
network can dynamically configure themselves based on these
attributes, thus maintaining consistency and efficiency in the
network configuration.
2. Security Considerations
The Prefix-List Community attribute is a Non-Transitive Extended
Community and should be treated with the same security considerations
as other BGP extended communities. Care should be taken to ensure
that only authorized routers and networks utilize this attribute to
prevent unauthorized or malicious routing changes.
To prevent unauthorized use of the Prefix-List Community attribute,
it is recommended to implement a filter or access control lists
(ACLs) and BGP authentication mechanisms by implementing session
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protection through TTL security [RFC5082], TCP Authentication Option
(TCP-AO) or Message Digest Algorithm 5 (MD5) and control-plane
filtering. [RFC7574].
3. References
3.1. Normative References
[RFC7153] Rosen, E. and Y. Rekhter, "IANA Registries for BGP
Extended Communities", RFC 7153, DOI 10.17487/RFC7153,
March 2014, <https://www.rfc-editor.org/info/rfc7153>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC7597] Troan, O., Ed., Dec, W., Li, X., Bao, C., Matsushima, S.,
Murakami, T., and T. Taylor, Ed., "Mapping of Address and
Port with Encapsulation (MAP-E)", RFC 7597,
DOI 10.17487/RFC7597, July 2015,
<https://www.rfc-editor.org/info/rfc7597>.
[RFC7599] Li, X., Bao, C., Dec, W., Ed., Troan, O., Matsushima, S.,
and T. Murakami, "Mapping of Address and Port using
Translation (MAP-T)", RFC 7599, DOI 10.17487/RFC7599, July
2015, <https://www.rfc-editor.org/info/rfc7599>.
3.2. Informative References
[RFC2858] Bates, T., Rekhter, Y., Chandra, R., and D. Katz,
"Multiprotocol Extensions for BGP-4", RFC 2858,
DOI 10.17487/RFC2858, June 2000,
<https://www.rfc-editor.org/info/rfc2858>.
[RFC4271] Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A
Border Gateway Protocol 4 (BGP-4)", RFC 4271,
DOI 10.17487/RFC4271, January 2006,
<https://www.rfc-editor.org/info/rfc4271>.
[RFC4760] Bates, T., Chandra, R., Katz, D., and Y. Rekhter,
"Multiprotocol Extensions for BGP-4", RFC 4760,
DOI 10.17487/RFC4760, January 2007,
<https://www.rfc-editor.org/info/rfc4760>.
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[RFC8642] Borkenhagen, J., Bush, R., Bonica, R., and S. Bayraktar,
"Policy Behavior for Well-Known BGP Communities",
RFC 8642, DOI 10.17487/RFC8642, August 2019,
<https://www.rfc-editor.org/info/rfc8642>.
[RFC7574] Bakker, A., Petrocco, R., and V. Grishchenko, "Peer-to-
Peer Streaming Peer Protocol (PPSPP)", RFC 7574,
DOI 10.17487/RFC7574, July 2015,
<https://www.rfc-editor.org/info/rfc7574>.
[RFC5082] Gill, V., Heasley, J., Meyer, D., Savola, P., Ed., and C.
Pignataro, "The Generalized TTL Security Mechanism
(GTSM)", RFC 5082, DOI 10.17487/RFC5082, October 2007,
<https://www.rfc-editor.org/info/rfc5082>.
Appendix A. Acronyms and Abbreviations
AFI: Address Family Identifier
BGP: Border Gateway Protocol
DMR: Default Mapping Rule
IP: Internet Protocol
IPv4: Internet Protocol version 4
IPv6: Internet Protocol version 6
MAP-T: Mapping of Address and Port using Translation
MAP-E: Mapping of Address and Port with Encapsulation
NLRI: Network Layer Reachability Information
VPN: Virtual Private Network
SAFI: Subsequent Address Family Identifier
Acknowledgements
To be added later
Contributors
To be added later
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Authors' Addresses
Moshiko Nayman (editor)
Juniper Networks
18 Buckingham Dr
Manalapan, NJ 07726
United States of America
Email: mnayman@juniper.net
Avinash Lingala
AT&T
3400 W Plano Pkwy
Plano, TX 75075
United States of America
Email: ar977m@att.com
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