Network Working Group Y. Rekhter
Request for Comments: 5668 Juniper Networks
Category: Standards Track S. Sangli
4-Octet AS Specific BGP Extended Community
This document defines a new type of a BGP extended community, which
carries a 4-octet Autonomous System (AS) number.
Status of This Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
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Rekhter, et al. Standards Track [Page 1]RFC 5668 4-Octet AS Specific Extended Community October 2009
not be created outside the IETF Standards Process, except to format
it for publication as an RFC or to translate it into languages other
This document defines a new type of BGP extended community [RFC4360]:
a 4-octet AS specific extended community. This type of extended
community is similar to the 2-octet AS specific extended community,
except that it can carry a 4-octet Autonomous System number.
1.1. Specification of Requirements
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. 4-Octet AS Specific Extended Community
This is an extended type with a Type field comprising 2 octets and a
Value field comprising 6 octets.
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
| 0x02 or 0x42 | Sub-Type | Global Administrator :
: Global Administrator (cont.) | Local Administrator |
The value of the high-order octet of this extended type is either
0x02 (for transitive communities) or 0x42 (for non-transitive
communities). The low-order octet of this extended type is used to
The Value field consists of 2 sub-fields:
Global Administrator sub-field: 4 octets
This sub-field contains a 4-octet Autonomous System number
assigned by IANA.
Rekhter, et al. Standards Track [Page 2]RFC 5668 4-Octet AS Specific Extended Community October 2009
Local Administrator sub-field: 2 octets
The organization identified by the Autonomous System number in
the Global Administrator sub-field can encode any information
in this sub-field. The format and meaning of the value encoded