consistent policy != consistent announcements

Randy Bush randy at
Thu Mar 13 14:31:00 UTC 1997

> My first concern is the loss of information when the route to M isn't
> announced.  This causes unfairness when traffic ends up taking the 'long'
> route.

My peer fears that and would like me to fix it.  I don't understand how I
can do that in a simple maintainable fashion.

> More than likely your peer is doing the same thing unto you.

Quite possibly, but they won't 'fess up to it.  And I don't want to whine at
them unless I know how to constructively address the opportunity (the peer
is a Californian:-).

> The second effect of M's route not being announced happens when traffic is
> blocked because no 'longer' path shows up anywhere else due to different
> route weightings and policy filters across various combinations of ASs.  I
> consider this possibility the more serious problem.  As the peering mesh
> becomes sparser, expect more missing in action paths, even if the physical
> connections exist the 'best' path may not be announced.

If my peer does not agree that my policy is reasonable and a consequence of
current tools, their reaction may be to reject inconsistent announcements
thereby increasing the likelihood that no path is propagated.


More information about the NANOG mailing list