Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

New Member

Not able to five full BGP route

Dear All,

Would appreicate if anyone can help me with some BGP problem

I have a 7206 VXR router running 12.3(2)T IOS. I am doing BGP with my customer who is using a 3640 with c3640-ix-mz.123-3a.bin as its IOS with about 128mb of ram.

What happen is that when I try to give him full routes, my router CPU will shoot up beyond 90% and stay up. Only when I put in a filter-list did the problem got resolved. Meaning, we can do BGP with each other and our advertisement is going through. Just that he can only received partial routes from me.

I am wondering where is the limitation on why my customer is not able to receive full routes from me and how can I go about resolving those problems.

Any assistance will be appreciated. Thanks.

Vincent

1 ACCEPTED SOLUTION

Accepted Solutions
Gold

Re: Not able to five full BGP route

I would say that 128MB is on the edge or two little. First, the Internet routing table is always growing, and I don't think 128MB will handle the number of routes we're talking about plus CEF tables and other things. Second the size of images has grown, so there is less and less of that 128MB available for the routing table each time you upgrade.

:-)

Russ.W

6 REPLIES
Gold

Re: Not able to five full BGP route

Do you have log adjacency tables on? I'd think that what's happening is the other router is either crashing or terminating the BGP sessions, which then causes your router to have to start over on the session constantly, which drives your cpu up. It's also possible that the other router is being pathological because it's running out of memory trying to receive all the routes, and causing your router to retransmit a lot, etc.

I woudl suggest either having the customer upgrade their memory, or accept partial routes.

Russ.W

Gold

Re: Not able to five full BGP route

Sorry, log adjacency changes! :-)

Russ.W

New Member

Re: Not able to five full BGP route

Dear Russ,

Thanks for the reply.

I do have log-adjacency-changes but only on my OSPF not on my BGP. The following is my router setting:

...

no synchronization

no bgp fast-external-fallover

bgp log-neighbor-changes

...

no auto-summary

...

I am just puzzled would not 128Mb of RAM be more than sufficient to meet the demand of full internet route? I have successful experience with getting the full routes at 70Mb.

Just wondering is there any possibility that it is in fact an IOS issue.

Regards,

Vincent

Gold

Re: Not able to five full BGP route

I would say that 128MB is on the edge or two little. First, the Internet routing table is always growing, and I don't think 128MB will handle the number of routes we're talking about plus CEF tables and other things. Second the size of images has grown, so there is less and less of that 128MB available for the routing table each time you upgrade.

:-)

Russ.W

New Member

Re: Not able to five full BGP route

Gee, thanks for the info Russ. Really appreciate your help in getting the answers for me.

Vincent

New Member

Re: Not able to five full BGP route

We have had success running a 3640 receiving full Internet routes before, but that was maybe 3 or 4 years ago. I'm not sure though that the routing table has grown significantly.

If you are still having a problem, try to see if the customer has configured any filter list or as-path list at their end, which could not limit you sending the routes to them, but which would limit which routes they accept.

But it is more likely that the customer router cannot handle the full Internet routes. If you do not find a solution, or the customer cannot upgrade, then consider advertising partial routes only.

115
Views
0
Helpful
6
Replies