>> Yet my upstream still prefers core2a as correct route to our network. I >> noticed, that only core2a networks have "announced" flag, is that right? >> Any other ideas what could be wrong? >> >If you look at the Loc-Rib aka 'bgpctl show rib 194.143.152.1 all' it will >show you that there are two networks for 194.143.152.0/23 on core2b. This >comes from the fact that core2a is announcing his network to core2b and >the route from core2a is considered better and therefor selected and >announced. The A flag is only set on local networks. > Actually if I run this command, it doesn't show any network: # bgpctl show rib 194.143.152.1 all flags: * = Valid, > = Selected, I = via IBGP, A = Announced origin: i = IGP, e = EGP, ? = Incomplete
flags destination gateway lpref med aspath origin (output is identical on both primary and secondary router). >Now if the upstreams always selects one route over another then it is a >missconfiguration on their side (e.g. there is still a static route >somewhere configured or something else). > I asked them for all the configuration they have for our network, they claim they don't have any static routes or any other routing protocol involved. They also sent me how my network looks from their routers (I still have prepend-self and prepend-neighbor values "1" on primary, not secondary router): sh ip bgp 194.143.152.1 BGP routing table entry for 194.143.152.0/23, version 73502 Paths: (4 available, best #1, table Default-IP-Routing-Table) Advertised to update-groups: 1 3 4 5 6 12 21178 159.148.214.98 from 159.148.214.99 (159.148.214.99) Origin IGP, localpref 100, valid, external, best Community: 2588:400 2588:500 2588:700 21178, (received-only) 159.148.214.98 from 159.148.214.99 (159.148.214.99) Origin IGP, localpref 100, valid, external 21178 21178 159.148.214.98 from 159.148.214.98 (159.148.214.98) Origin IGP, localpref 100, valid, external Community: 2588:400 2588:500 2588:700 21178 21178, (received-only) 159.148.214.98 from 159.148.214.98 (159.148.214.98) Origin IGP, localpref 100, valid, external It looks like secondary router announces best path to primary router is dirrect connection, except that path it is announcing is shorter than expected. Is that correct behavior? Should it be fixed by filters or my secondary router wasn't supposed to announce such short path in the first place? I can also send configuration options of upstream router if necessary. Thank you, Peter
