BGP receives incomplete table route

[g.careaga]

Hi team, I am having troubles with a Cisco 2801 running Version 12.4(7a) and in another running 12.4(9) IOS version. The problem is that sometimes they receive about 500 routes when their neigbour advertises about 1600; but some times BGP works good and they receive 1600 like as it is supposed to be, but if after a moment you run a "clear bgp*" the routes desappear after and then after the router syncronize bgp again the route table is incomplete with about only 500 routes again.

Here I attach show-tech file that belongs to one router 2800 with this issue.

The problem is with AS bgp 65200, with for example neighbor 172.26.255.93.

Is there any known workaround?

Thanks a lot Team

Best regards to all

[Giuseppe Larosa]

hello Gabriel,

your router is in AS65200

the neighbor is in as10834

you accept up to 10 times your own AS 65200 in updates

neighbor 172.26.255.93 allowas-in 10

you also have iBGP neighbors from which you not accept anything

neighbor 77.0.120.9 distribute-list local in

neighbor 77.0.120.25 distribute-list local in

ip access-list extended local

deny ip any any

and you try to do AS path prepending to your iBGP neighbor (as path attribute is not changed this should be not effective)

neighbor 77.0.120.9 route-map prepend out

this last command is wrong in my opinion

you should think to send few summarized routes to this device.

1500 routes inside a VPN if in all cases you need to send traffic to the same neighbor you don't need to receive all this detail

Hope to help

Giuseppe