BGP Message types

BGP message types

New relation between two BGP peers:

• Open
  • type 1
  • Version4 (ipv4), AS#, Hold time, Router-iD, parameters.

• Update
  • type 2
  • Informs neighbors about withdrawn routes, changed routes, new routes.
  • Used to exchange PAs and the Network Layer Reachability Information (NLRI).

(When adding the 30.30.30.0/24 on Router2 loopback2, and adding the network in the BGP config:)

• Notification
  • type 3
  • Used to signal a BGP error. Typically resets the neighbor
• Keepalive
  • type 4
  • Just the BGP header

BGP table / Commands

show ip bgp
show ip bgp neighbor 10.10.10.10 advertised-routes
show ip bgp neighbor 10.10.10.10 received-routes
show ip bgp neighbor 10.10.10.10 routes
show ip bgp sum