My Public IP Appear in disappear for the global BGP table,why?

[Ibrahim Jamil]

Hi Experts

our enterprise is multihoming to two ISPs we have a Public independent class C Address IP along with public AS , according to looking glass my Public IP Appear in disappear for the global BGP table,why is that happened?is it my problem or ISP problem pls how to troubleshoot

thanks

jamil

[John Blakley]

Jamil,

You can do a "sho ip bgp neigh x.x.x.x advertised-routes" on your router. If you see the route that you're sending to them, it's probably a problem with them.

HTH,

John

[Ibrahim Jamil]

Hi j.blakley

thanks for ur reply

why this problem happened?what is the root cause of this issue?how to deal with this issue?

what i should say to providers

thanks

jamil

[John Blakley]

First, do you show that you're advertising the network? If you are, you should call them and tell them that you don't see your advertised block on a looking glass server. Try other looking glass servers too to make sure that it's not just the one that you don't see it on. I've noticed that sometimes, even though you send to a provider, the provider will send to their peers who may then in turn summarize networks. You may not see your specific network any longer because a provider decided to summarize somewhere.

HTH,

John

[Ibrahim Jamil]

Hi John

i see the route advertised to them , and i have Internet via them ,but some time o have disconnection for 5 second and my prifex disappear then appear, i m confused

thanks

jamil

[John Blakley]

Are you losing your peering with them? Do a show ip bgp summary to see how long the peering has been up. Is this a route that's on the router, meaning assigned to an interface? If so, make sure the interface isn't flapping. If not, try to track down what router is advertising this route to you and see if it's having problems. It's possible that they've dampended this route if it's flapping which means it will have to be stable before they allow the route to be readvertised from them.

John