Task 2.9 BGP Filtering
When I first looked at task - I thought that addition neighbor send-community statements were required on R1 for R1 to R5 peering and also on R4 for R4 to R5 peering to allow for the failure of R5's s0/0/0 frame relay circuit. In this situation traffic reroutes via VLAN 45.
How wrong was this assumption. As all of the iBGP peerings are using loopback, the peering between R1 and R5 remains established during the above failure - the BGP session simply routes through R4, so R5 always gets the prefix 172.21.1.0/24 with the community local-as.
Yet another case of over config for me [:$]