Internet DRAFT - draft-zzhang-idr-bitmask-route-target
draft-zzhang-idr-bitmask-route-target
idr Z. Zhang
Internet-Draft S. Sangli
Intended status: Standards Track J. Haas
Expires: 23 October 2021 Juniper Networks
21 April 2021
Bitmask Route Target
draft-zzhang-idr-bitmask-route-target-01
Abstract
This document specifies a new type of Route Target called Bitmask
Route Target as a BGP Community Container. The key element of a
Bitmask Route Target is a Bitmask. Two Bitmask Route Targets are
considered equivalent for the purpose of controlling route
propagation (via Route Target Constraints) and importation if the
result of logical "AND" operation of the Bitmask of the two is non-
zero.
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] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
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
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
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."
This Internet-Draft will expire on 23 October 2021.
Zhang, et al. Expires 23 October 2021 [Page 1]
Internet-Draft bitmask-route-target April 2021
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 publication of this document.
Please review these documents carefully, as they describe your rights
and restrictions with respect to this document. Code Components
extracted from this document must include Simplified BSD License text
as described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Specification . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1. Matching Semantics . . . . . . . . . . . . . . . . . . . 3
3. Error Handling . . . . . . . . . . . . . . . . . . . . . . . 4
4. Security Considerations . . . . . . . . . . . . . . . . . . . 4
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 6
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 6
7.1. Normative References . . . . . . . . . . . . . . . . . . 6
7.2. Informative References . . . . . . . . . . . . . . . . . 7
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7
1. Introduction
The importation and propagation of BGP routes can be controlled using
Route Targets [RFC4364] and Constrained Route Target Distribution
(RT-C) [RFC4684]. RT-C relies on matching a Route Target prefix.
The typical matching use case is the full 8-octet encoding of the
Route Target Extended Community.
For some applications, it's desirable to have a Route Target with the
semantic of a bit-string. For such situations and it may be
desirable to match such bit-string Route Targets that have specific
bits set. This document defines a new type of Route Target for that
purpose.
An example use case of this Bitmask Route Target is documented in
[I-D.zzhang-teas-network-slicing-with-flex-te].
The use of Bitmask Route Target with Constrained Route Target
Distribution is specified separately in
[I-D.zzhang-idr-bgp-rt-constrains-extension].
Zhang, et al. Expires 23 October 2021 [Page 2]
Internet-Draft bitmask-route-target April 2021
2. Specification
The Bitmask Route Target is a Transitive BGP Community Container of
type TBD1 [I-D.ietf-idr-wide-bgp-communities].
The semantics of Global Administrator and Local Administor are
identical to those in [RFC4360].
The container's contents is a series of Bitmask Route Targets. Each
Bitmask Route Target includes a 1-octet Global Administrator (GA)
Type, a 1-octet GA Sub-Type, 1-octet GA Length, a variable length GA,
a 4-octet Local Administrator (LA), a 1-octet Bitmask Length in
number of octets, and a variable length Bitmask.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| GA Type | GA Sub-Type | GA Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Global Administrator (variable length) ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Local Administrator |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Bitmask Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Bitmask (variable length) ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The following GA Types and corresponding lengths are defined in this
document:
1: AS Number, 4-octets
2: IPv4 Address, 4-octets
3: IPv6 Address, 16-octets
The follow GA Sub-Types are defined in this document:
2: Route-Target
2.1. Matching Semantics
A Bitmask Route Target, A, is considered to match Bitmask Route
Target, B, for the purpose of controlling propagation and importation
of a route with an attached Bitmask Route Target B if the following
conditions are met:
Zhang, et al. Expires 23 October 2021 [Page 3]
Internet-Draft bitmask-route-target April 2021
* The GA Type, GA Sub-Type, GA Length, GA, and LA fields in A and B
match.
* Either:
- The Bitmask Length of A is 0. In other words, "match all".
- The result of the logical "AND" operation of the Bitmask field
in A and B is not 0. When A and B have different Bitmask
Lengths, the shorter Route Target's Bitmask is considered to be
padded with zeroes for match purposes vs. the longer one.
3. Error Handling
A Bitmask Route Target MUST NOT be originated with a RESERVED GA
Type. Implementations receiving BGP Routes with a RESERVED Bitmask
Route Target MUST check its syntactic correctness and MAY silently
discard it.
A Bitmask Route Target SHOULD NOT be originated with a Bitmask Length
of 0.
A Bitmask Route Target is considered malformed if:
* The length of the Bitmask Route Target is less than the minimum
length of 8: 1-octet GA Type, 1-octet GA Sub-Type, 1-octet GA
Length, 0-length GA, 4-octet LA, 0-octet Bitmask.
* The Bitmask Route Target GA Type is known by the implementation
and the GA Length is incorrect vs. the registered GA Type.
* The total computed length of the Bitmask Route Targets in a BGP
Community Container is not identical to the BGP Community
Container Length. Each Bitmask Route Target's computed length is:
1-octet GA Type, 1-octet GA Length field, N-octet GA Length value,
4-octet LA field, 1-octet Bitmask Length, N-octet Bitmask Length
value.
BGP Updates containing malformed Bitmask Route Targets should use the
Treat-as-withdraw behavior for the routes in the Update according to
[RFC7606].
4. Security Considerations
This document does not change security aspects as discussed in
[RFC4364] and [I-D.ietf-idr-wide-bgp-communities].
Zhang, et al. Expires 23 October 2021 [Page 4]
Internet-Draft bitmask-route-target April 2021
5. IANA Considerations
This document requests IANA to assign a BGP Community Container Type
for the Bitmask Route Target from the "BGP Community Container Types"
registry for TBD1.
This document requests IANA to setup a "Bitmask Route Target Global
Administrator Type Registry". The initial allocation and policy for
this registry is:
+==========+========================+================+===========+
| GA Type | GA Type Name | GA Type Length | Reference |
| | | (octets) | |
+==========+========================+================+===========+
| 0 | RESERVED | UNSPECIFIED | This |
| | | | document |
+----------+------------------------+----------------+-----------+
| 1 | AS Number | 4 | This |
| | | | document |
+----------+------------------------+----------------+-----------+
| 2 | IPv4 Address | 4 | This |
| | | | document |
+----------+------------------------+----------------+-----------+
| 3 | IPv6 Address | 16 | This |
| | | | document |
+----------+------------------------+----------------+-----------+
| 4..127 | Available, | TBD | - |
| | Specification Required | | |
+----------+------------------------+----------------+-----------+
| 128..254 | Available, First Come, | TBD | - |
| | First Served | | |
+----------+------------------------+----------------+-----------+
| 255 | RESERVED | UNSPECIFIED | This |
| | | | document |
+----------+------------------------+----------------+-----------+
Table 1: Bitmask Route Target GA-Type Registry
This document requests IANA to setup a "Bitmask Route Target Global
Administrator Sub-Type Registry". The initial allocation and policy
for this registry is:
Zhang, et al. Expires 23 October 2021 [Page 5]
Internet-Draft bitmask-route-target April 2021
+=============+=====================================+===============+
| GA Sub-Type | GA Sub-Type Name | Reference |
+=============+=====================================+===============+
| 0 | RESERVED | This document |
+-------------+-------------------------------------+---------------+
| 1 | Available, Specification Required | - |
+-------------+-------------------------------------+---------------+
| 2 | Route-Target | This document |
+-------------+-------------------------------------+---------------+
| 3..127 | Available, Specification Required | - |
+-------------+-------------------------------------+---------------+
| 128..254 | Available, First Come, First | - |
| | Served | |
+-------------+-------------------------------------+---------------+
| 255 | RESERVED | This document |
+-------------+-------------------------------------+---------------+
Table 2: Bitmask Route Target GA-Sub-Type Registry
6. Acknowledgements
The authors thank John Scudder for his comments and suggestions.
7. References
7.1. Normative References
[I-D.ietf-idr-wide-bgp-communities]
Raszuk, R., Haas, J., Lange, A., Decraene, B., Amante, S.,
and P. Jakma, "BGP Community Container Attribute", Work in
Progress, Internet-Draft, draft-ietf-idr-wide-bgp-
communities-05, 2 July 2018, <http://www.ietf.org/
internet-drafts/draft-ietf-idr-wide-bgp-communities-
05.txt>.
[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>.
[RFC7606] Chen, E., Ed., Scudder, J., Ed., Mohapatra, P., and K.
Patel, "Revised Error Handling for BGP UPDATE Messages",
RFC 7606, DOI 10.17487/RFC7606, August 2015,
<https://www.rfc-editor.org/info/rfc7606>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
Zhang, et al. Expires 23 October 2021 [Page 6]
Internet-Draft bitmask-route-target April 2021
7.2. Informative References
[I-D.zzhang-idr-bgp-rt-constrains-extension]
Zhang, Z. and J. Haas, "Generic Route Constraint
Distribution Mechanism for BGP", Work in Progress,
Internet-Draft, draft-zzhang-idr-bgp-rt-constrains-
extension-01, 11 January 2021, <http://www.ietf.org/
internet-drafts/draft-zzhang-idr-bgp-rt-constrains-
extension-01.txt>.
[I-D.zzhang-teas-network-slicing-with-flex-te]
Zhang, Z., Hegde, S., and A. Gulko, "Network Slicing with
Flexible Traffic Engineering", Work in Progress, Internet-
Draft, draft-zzhang-teas-network-slicing-with-flex-te-00,
13 July 2020, <http://www.ietf.org/internet-drafts/draft-
zzhang-teas-network-slicing-with-flex-te-00.txt>.
[RFC4360] Sangli, S., Tappan, D., and Y. Rekhter, "BGP Extended
Communities Attribute", RFC 4360, DOI 10.17487/RFC4360,
February 2006, <https://www.rfc-editor.org/info/rfc4360>.
[RFC4364] Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private
Networks (VPNs)", RFC 4364, DOI 10.17487/RFC4364, February
2006, <https://www.rfc-editor.org/info/rfc4364>.
[RFC4684] Marques, P., Bonica, R., Fang, L., Martini, L., Raszuk,
R., Patel, K., and J. Guichard, "Constrained Route
Distribution for Border Gateway Protocol/MultiProtocol
Label Switching (BGP/MPLS) Internet Protocol (IP) Virtual
Private Networks (VPNs)", RFC 4684, DOI 10.17487/RFC4684,
November 2006, <https://www.rfc-editor.org/info/rfc4684>.
Authors' Addresses
Zhaohui Zhang
Juniper Networks
Email: zzhang@juniper.net
Srihari Sangli
Juniper Networks
Email: ssangli@juniper.net
Zhang, et al. Expires 23 October 2021 [Page 7]
Internet-Draft bitmask-route-target April 2021
Jeffrey Haas
Juniper Networks
Email: jhaas@juniper.net
Zhang, et al. Expires 23 October 2021 [Page 8]
