Hi, I can think of two reasons for such behavior: - one of the attributes of these routes changed suddenly, so they have been reannounced by your peer, - you sent a 'route refresh' request to this peer, asking him to reannounce all his table. Other than that, I don't see why a peer would resend lots of already-announced prefixes.. cheers, Mateusz On 08/04/2014 04:29 AM, Song Li wrote:

Hi everyone,

I have a question about bgp updates:

BGP uses an incremental update strategy to conserve bandwidth and processing power. That is, after initial exchange of complete routing information, a pair of BGP routers exchanges only the changes to that information. ( from RFC4274)

According to this principle, if an AS suddenly announced a lot of updates (as below), can it be regarded as an anomaly such as BGP session reset? I wish to know if there are other reasons can result in this anomaly.

Thanks!

BGP4MP|04/23/14 13:05:12|A|216.218.252.164|6939|218.189.24.0/24|6939 15412 9304|IGP BGP4MP|04/23/14 13:05:12|A|216.218.252.164|6939|218.189.28.0/24|6939 15412 9304|IGP BGP4MP|04/23/14 13:05:12|A|216.218.252.164|6939|218.189.16.0/24|6939 15412 9304|IGP BGP4MP|04/23/14 13:05:12|A|216.218.252.164|6939|218.189.20.0/24|6939 15412 9304|IGP BGP4MP|04/23/14 13:05:12|A|216.218.252.164|6939|218.189.16.0/20|6939 15412 9304|IGP BGP4MP|04/23/14 13:05:12|A|216.218.252.164|6939|218.189.12.0/24|6939 15412 9304|IGP BGP4MP|04/23/14 13:05:12|A|216.218.252.164|6939|218.189.12.0/22|6939 15412 9304|IGP BGP4MP|04/23/14 13:05:12|A|216.218.252.164|6939|218.189.204.0/23|6939 4436 25973 9304|IGP BGP4MP|04/23/14 13:05:12|A|216.218.252.164|6939|218.189.208.0/21|6939 4436 25973 9304|IGP BGP4MP|04/23/14 13:05:12|A|216.218.252.164|6939|218.189.8.0/24|6939 4436 25973 9304|IGP BGP4MP|04/23/14 13:05:12|A|216.218.252.164|6939|202.1.32.0/20|6939 15412 9304|IGP BGP4MP|04/23/14 13:05:12|A|216.218.252.164|6939|218.189.204.0/23|6939 9304|IGP BGP4MP|04/23/14 13:05:12|A|216.218.252.164|6939|218.189.208.0/21|6939 9304|IGP BGP4MP|04/23/14 13:05:12|A|216.218.252.164|6939|218.189.24.0/24|6939 9304|IGP BGP4MP|04/23/14 13:05:12|A|216.218.252.164|6939|218.189.28.0/24|6939 9304|IGP BGP4MP|04/23/14 13:05:12|A|216.218.252.164|6939|218.189.16.0/24|6939 9304|IGP BGP4MP|04/23/14 13:05:12|A|216.218.252.164|6939|218.189.20.0/24|6939 9304|IGP BGP4MP|04/23/14 13:05:12|A|216.218.252.164|6939|218.189.16.0/20|6939 9304|IGP BGP4MP|04/23/14 13:05:12|A|216.218.252.164|6939|218.189.12.0/24|6939 9304|IGP BGP4MP|04/23/14 13:05:12|A|216.218.252.164|6939|218.189.12.0/22|6939 9304|IGP BGP4MP|04/23/14 13:05:12|A|216.218.252.164|6939|218.189.8.0/24|6939 9304|IGP BGP4MP|04/23/14 13:05:12|A|216.218.252.164|6939|202.1.32.0/20|6939 9304|IGP BGP4MP|04/23/14 13:05:12|A|216.218.252.164|6939|114.134.83.0/24|6939 3549 9304|IGP BGP4MP|04/23/14 13:05:12|A|216.218.252.164|6939|203.90.243.0/24|6939 15412 9304|IGP BGP4MP|04/23/14 13:05:12|A|216.218.252.164|6939|203.90.251.0/24|6939 15412 9304|IGP BGP4MP|04/23/14 13:05:12|A|216.218.252.164|6939|118.143.224.0/20|6939 15412 9304|IGP BGP4MP|04/23/14 13:05:12|A|216.218.252.164|6939|118.143.232.0/24|6939 15412 9304|IGP BGP4MP|04/23/14 13:05:12|A|216.218.252.164|6939|202.46.57.0/24|6939 15412 9304|IGP BGP4MP|04/23/14 13:05:12|A|216.218.252.164|6939|202.46.53.0/24|6939 15412 9304|IGP BGP4MP|04/23/14 13:05:12|A|216.218.252.164|6939|202.46.61.0/24|6939 15412 9304|IGP BGP4MP|04/23/14 13:05:12|A|216.218.252.164|6939|202.46.49.0/24|6939 15412 9304|IGP BGP4MP|04/23/14 13:05:12|A|216.218.252.164|6939|103.17.240.0/22|6939 15412 9304|IGP BGP4MP|04/23/14 13:05:12|A|216.218.252.164|6939|103.17.240.0/24|6939 15412 9304|IGP BGP4MP|04/23/14 13:05:12|A|216.218.252.164|6939|112.73.6.0/23|6939 15412 9304|IGP BGP4MP|04/23/14 13:05:13|A|216.218.252.164|6939|118.194.231.0/24|6939 3549 9304|IGP BGP4MP|04/23/14 13:05:13|A|216.218.252.164|6939|175.100.198.0/24|6939 3549 9304|IGP BGP4MP|04/23/14 13:05:13|A|216.218.252.164|6939|175.100.206.0/24|6939 15412 9304|IGP BGP4MP|04/23/14 13:05:13|A|216.218.252.164|6939|210.0.209.0/24|6939 4436 25973 9304|IGP BGP4MP|04/23/14 13:05:13|A|216.218.252.164|6939|210.3.0.0/22|6939 4436 25973 9304|IGP BGP4MP|04/23/14 13:05:13|A|216.218.252.164|6939|210.3.4.0/23|6939 4436 25973 9304|IGP BGP4MP|04/23/14 13:05:13|A|216.218.252.164|6939|103.227.207.0/24|6939 1299 3257 9304|IGP BGP4MP|04/23/14 13:05:13|A|216.218.252.164|6939|114.134.83.0/24|6939 9304|IGP BGP4MP|04/23/14 13:05:13|A|216.218.252.164|6939|203.90.243.0/24|6939 9304|IGP BGP4MP|04/23/14 13:05:13|A|216.218.252.164|6939|203.90.251.0/24|6939 9304|IGP BGP4MP|04/23/14 13:05:13|A|216.218.252.164|6939|118.143.224.0/20|6939 9304|IGP BGP4MP|04/23/14 13:05:13|A|216.218.252.164|6939|118.143.232.0/24|6939 9304|IGP BGP4MP|04/23/14 13:05:13|A|216.218.252.164|6939|202.46.57.0/24|6939 9304|IGP BGP4MP|04/23/14 13:05:13|A|216.218.252.164|6939|202.46.53.0/24|6939 9304|IGP BGP4MP|04/23/14 13:05:13|A|216.218.252.164|6939|202.46.61.0/24|6939 9304|IGP BGP4MP|04/23/14 13:05:13|A|216.218.252.164|6939|202.46.49.0/24|6939 9304|IGP BGP4MP|04/23/14 13:05:13|A|216.218.252.164|6939|103.17.240.0/22|6939 9304|IGP BGP4MP|04/23/14 13:05:13|A|216.218.252.164|6939|103.17.240.0/24|6939 9304|IGP BGP4MP|04/23/14 13:05:13|A|216.218.252.164|6939|112.73.6.0/23|6939 9304|IGP BGP4MP|04/23/14 13:05:13|A|216.218.252.164|6939|118.194.231.0/24|6939 9304|IGP BGP4MP|04/23/14 13:05:13|A|216.218.252.164|6939|175.100.206.0/24|6939 9304|IGP BGP4MP|04/23/14 13:05:13|A|216.218.252.164|6939|210.0.209.0/24|6939 9304|IGP