While researching an RFC1997 issue this morning, I made the following
observations:
According to RFC1997:
"
Well-known Communities
The following communities have global significance and their
operations shall be implemented in any community-attribute-aware BGP
speaker.
NO_EXPORT (0xFFFFFF01)
All routes received carrying a communities attribute
containing this value MUST NOT be advertised outside a BGP
confederation boundary (a stand-alone autonomous system that
is not part of a confederation should be considered a
confederation itself).
NO_ADVERTISE (0xFFFFFF02)
All routes received carrying a communities attribute
containing this value MUST NOT be advertised to other BGP
peers.
NO_EXPORT_SUBCONFED (0xFFFFFF03)
All routes received carrying a communities attribute
containing this value MUST NOT be advertised to external BGP
peers (this includes peers in other members autonomous
systems inside a BGP confederation).
"
On Cisco's site at
http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/12cgcr/np1_c/1cprt1/1cbgp.htm#5082
I find the following:
"
internet - Advertise this route to the Internet community. All routers
belong to it.
no-export - Do not advertise this route to EBGP peers.
no-advertise - Do not advertise this route to any peer (internal or
external).
local-as - Send this route to peers in other sub-autonomous systems within
the local confederation. Do not advertise this route to an
external system.
"
Unless I'm mistaken, there are some potential interop issues with this.
CISCO no-export = RFC1997 NO_EXPORT_SUBCONFED
CISCO no-advertise = RFC1997 NO_ADVERTISE
CISCO local-as = RFC1997 NO_EXPORT
Can someone more familiar with the RFC1997 implementation in IOS comment
on this?
Thanks,