Question on Unrecognized BGP Path Attribute

Tue Jul 24 18:27:35 UTC 2007

On Jul 23, 2007, at 12:48 PM, Xin Liu wrote:

> I have a question about unrecognized BGP path attribute. According to
> RFC4271, when a BGP router sees an UPDATE with an unrecognized
> optional and transitive path attribute, it should retain the
> attribute, and if the path is selected, it should propagate the
> attribute to its neighbors. My question is, if later the router sees
> an update to the path in which only the unrecognized attribute has
> changed, should it immediately propagate the change to its neighbors?
> My guess is a yes, but I'm not sure because it's not explicitly
> written down in the RFC.

Yes, that was the intent.

A better place for this might be the IETF's IDR mailing list.

Tony