Job,
On Tue, Mar 20, 2018 at 01:52:23PM +0000, Job Snijders wrote: > Hi all, > > Reudiger Volk mentioned something interesting at the microphone > yesterday about getting more visiblity into BGP UPDATES that are > rejected/dropped somewhere in the policy chain transitioning from > Adj-RIB-In to Loc-RIB. > > To make a crude route-map example: > > ip prefix-list allow-ebgp-in permit 192.0.2.0/24 > ! > route-map ebgp-in permit 10 > match ip address prefix-list allow-ebgp-in > ! > route-map ebgp-in deny 20 > bmp-log-code 21438 > > It would be great to see what UPDATEs get dropped in "route-map ebgp-in deny > 20". > It would perhaps be quite useful if we can get to the point where you > can even attach custom policy-exit codes to the "Dropped Updates" send > in this new BMP feed. I can see how this makes operational life easier. The "exit code" is fairly reasonable. The "dropped updates" can be problematic depending on what you meant. If you meant that the routes were discarded and not kept as inactive, implementations may need mirror mode support since the route would not be stored in the RIB. Routes that are simply rejected but stored in the rib (e.g. "keep all" in JunOS) can be reported as part of post-policy monitor mode. > > RFC 4271 Section 9.1: "The Decision Process selects routes for > subsequent advertisement by applying the policies in the local > Policy Information Base (PIB) to the routes stored in its > Adj-RIBs-In. The output of the Decision Process is the set of > routes that will be advertised to peers; the selected routes will be > stored in the local speaker's Adj-RIBs-Out, according to policy." > > Perhaps a series of BMP "PIB" drafts are in order? PIB docs were mostly left out of scope except as a general abstraction to talk about in the BGP standardization effort because no one can agree on The One True Policy Engine. See similar conversation occurring right now in the rtgwg policy yang model. > Is this worthy of a new BMP draft? Are there volunteers? I'd suggest keeping the scope to the bmp-log-code. -- Jeff _______________________________________________ GROW mailing list [email protected] https://www.ietf.org/mailman/listinfo/grow
