Inline with [Shunwan] Thanks, Shunwan
-----Original Message----- From: GROW [mailto:[email protected]] On Behalf Of Jeffrey Haas Sent: Friday, October 12, 2018 4:50 AM To: Tim Evens (tievens) <[email protected]> Cc: [email protected] Subject: Re: [GROW] bmp rib-out pre-policy questions (was Re: I-D Action: draft-ietf-grow-bmp-adj-rib-out-02.txt) Tim, On Thu, Oct 04, 2018 at 11:42:34PM +0000, Tim Evens (tievens) wrote: > On 10/4/18, 12:41 PM, "GROW on behalf of Jeffrey Haas" <[email protected] > on behalf of [email protected]> wrote: > > > > : Depending on BGP peering session type (IBGP, IBGP route reflector > > : client, EBGP) the candidate routes that make up the Pre-Policy Adj- > > : RIB-Out do not contain all local-rib routes. Pre-Policy Adj-RIB-Out > > : conveys only routes that are available based on the peering type. > > : Post-Policy represents the filtered/changed routes from the > > available > > > > The first one deals with the wording above. I suspect what is intended > > to > > be said is effectively that the route considered might not be a BGP > > route? > > In other words, the Adj-RIB-Out Pre-Policy is exactly what would > be advertised had there been no egress policy applied. This is > peer specific. This sentence really should go into the draft since it makes it much clearer what you're intending. > <Tim> Adj-RIB-Out Pre-Policy should be the routes that would be advertised had > there been no egress policy applied. The question of best, add-paths, > ... > shouldn’t change this as that would be based on the peering > configuration. So, offering some concrete examples: Example 1: - Destination D is the active route. - Destination D would not be eligible for advertisement to an internal peer because it'd loop. - best-external is configured. - Backup path B the best external path is advertised. So, in this situation, you expect B to be advertised sans export policy being applied as the pre-policy route? [Shunwan] IMO, best-external should be considered as one of the egress policies, so path B cannot exist in the pre-policy route set. Example 2: - Add-paths is enabled. - Destination D1 is the active route. D2..Dn are add-paths eligible backup paths. - Post-policy, D1..Dn are advertised. In this situation, what is advertised in pre-policy? [Shunwan] Add-paths knob is also considered as one of the egress policies, so only destination D1 is advertised in pre-policy in this case. My 2 cents. > There are some folks that are having a hard time with understanding how > we take peering configuration into account, but IMO, we (a) can get some > of this via the OPEN messages in PEER UP and (b) consider > configuration. FWIW, I find this point clear. -- Jeff _______________________________________________ GROW mailing list [email protected] https://www.ietf.org/mailman/listinfo/grow _______________________________________________ GROW mailing list [email protected] https://www.ietf.org/mailman/listinfo/grow
