I have a question about BGP convergence time.
Consider an MPLS core and a customer on his own VPN (VRF) across the ISP's core network.
CE to PE is eBGP.
When I remove a route on the CE router, the other CE router (across the Core) detects it at once and removes it from the BGP table and the RIB.
But, when I add/publish a new route on the CE's BGP process, it takes a few seconds (say 30 to 50) for the other CE router to add to the BGP table and hence the RIB.
Is this common ? Does BGP take a while to publish routes to the other neighbor or is it because of delay across the core ? If it is, then why does the Withdrawals take place real quick ?
I did some debug bgp update events .. and I could see that the BGP UPDATES for new advertisements and withdraws happen instantaneously..
101043: Mar 6 13:25:35.480: BGP(0): 18.104.22.168 rcvd UPDATE w/ attr: nexthop 22.214.171.124/30, origin ?, path 5577 5577
101044: Mar 6 13:25:35.480: BGP(0): 126.96.36.199 rcvd 10.250.250.0/24
101045: Mar 6 13:25:35.484: BGP(0): 188.8.131.52 rcvd 184.108.40.206/30
101046: Mar 6 13:25:35.484: BGP(0): Revise route installing 1 of 1 routes for 10.250.250.0/24 -> 220.127.116.11 (main) to main IP table
101047: Mar 6 13:25:35.484: BGP(0): Revise route installing 1 of 1 routes for 18.104.22.168/30 -> 22.214.171.124 (main) to main