A. Verify that the UDP port 179 traffic is not being blocked by an ACL or firewall between the two IBGP peers

B. Verify that the network command under router BGP is configured correct on each router for announcing the router's loopback interface in BGP

C. Verify that the ttl-security command under the BGP neighbor is configured correctly on each router to enable the router to send the BGP packets using a proper TTL value

D. Verify that the ibgp-multihop command under the BGP neighbor is configured correctly on each router

E. Verify that the update-source loopback command under the BGP neighbor is configured correctly on each router

F. Verify that the loopback interfaces are reachable over the IGP