Today a little review :
edge12.bor03>show ip bg 37.8.8.8 BGP routing table entry for 37.8.0.0/20, version 47221703 Paths: (3 available, best #2, table Default-IP-Routing-Table) Advertised to update-groups: 1 15975, (received-only) 17.69.240.117 from 17.69.240.117 (17.69.255.1) Origin IGP, metric 16, localpref 500, valid, internal 12671 15975 15975 15975 15975, (received & used) 46.218.1.1 from 46.218.1.1 (172.17.1.6) Origin IGP, localpref 100, valid, external, best 12671 15975 15975 15975 15975, (received & used) 46.218.1.1 from 46.218.1.1 (172.17.1.2) Origin IGP, localpref 100, valid, external edge12.bor03>
Why the path through 17.69.240.117 is not used, although it is the a better path to 37.8.0.0/20 ?
Why is it marked as “received-only”
“Received-only” means as it says that this prefix is received, stored in Adj-IN, but cannot be selected for a valid prefix. Why ?
Lot of reasons. Commons are : route-maps, NEXTHOP not reachable…
http://www.cisco.com/c/en/us/support/docs/ip/border-gateway-protocol-bgp/13753-25.html
In my example, the problem is here : a route-map without an explicit permit.
BGP review – ‘received-only’ prefix state