Claudio Jeker wrote:
On Wed, Dec 10, 2008 at 04:47:31PM -0500, Ted Unangst wrote:
On Wed, Dec 10, 2008 at 4:38 PM, Claudio Jeker <cje...@diehard.n-r-g.com> wrote:
I looked at the porblem and I'm currently unsure what the best way is to
handle such bad AS4_* attributes. The RFC in all its glory does not
mention how to handle errors. So at the moment I'm in favor of just
dropping/ignoring the bad optional attribute but I need to recheck with
the BGP RFC to see if this is valid. Another solution is to ignore the
full update but I have a bad feeling about that.
Can you ignore just the route with the bad attribute? We don't want
to propagate it more.
The best thing we can do is to mark the update as ineligible so it will
not propaget further and will not be used but this is a quite radical
measure. On the other hand this is porbably the safest way to handle this
error.
Comments?
My thinking is in line with yours. RFC4271 doesn't appear to specify how
to handle this scenario gracefully,
as already mentioned here:
http://www.merit.edu/mail.archives/nanog/msg13422.html
Apparently there are already enough BGP speakers on the net that don't
check for a valid AS4_PATH before announcing it onwards to cause
problems for OpenBGPd users, if not others.
I'd rather be missing a route than missing an entire feed and/or
propagating attributes that will kill others' BGP sessions.
-tico
