Re: iBGP and EBGP

shahzad.rasheed · ‎09-13-2005

I am facing a problem regarding routing between iBGP and eBGP.

Within my AS i am using iBGP and with my provider EBGP, routes learned via iBGP are not being advertised to my provider by EBGP. My gateway router has all routes in its routing table learnt by iBGP but EBGP is not advertising these routes. I have given the Network command but no use.

Please help...Thanks.

Shahzad Rasheed, Dancom Online Pakistan.

attrgautam · ‎09-13-2005

Can you show the configuration at ur end and at your upstream end ?

shahzad.rasheed · ‎09-13-2005

Here is the configuration of my GW ,

router bgp xxxx

no synchronization

bgp router-id xxxxx

no bgp default ipv4-unicast

bgp log-neighbor-changes

neighbor xxx.125.xxx.137 remote-as xxxx

neighbor xxx.125.xxx.137 description PTCL

neighbor xxx.125.xxx.137 update-source Loopback0

neighbor xxx.xxx.176.251 remote-as xxxxx

neighbor xxx.xxx.176.251 description XXXISB

neighbor xxx.xxx.176.251 update-source Loopback3

no auto-summary

!

address-family ipv4

neighbor xxx.125.xxx.137 activate

neighbor xxx.125.xxx.137 soft-reconfiguration inbound

neighbor xxx.125.xxx.137 distribute-list PERMIT_TO_PTCL out

neighbor xxx.xxx.176.251 activate

neighbor xxx.xxx.176.251 soft-reconfiguration inbound

neighbor xxx.xxx.176.251 prefix-list PERMIT_FROM_XXXISB in

neighbor xxx.xxx.176.251 prefix-list PERMIT_TO_XXXISB out

no auto-summary

no synchronization

network xxx.xxx.12.0

network xxx.xxx.13.0

network xxx.xxx.15.0

network xxx.xxx.17.0

network xxx.xxx.18.0

network xxx.xxx.19.0

network xxx.xxx.10.0

network xxx.xxx.11.0

network xxx.xxx.17.0

network xxx.xxx.174.0

network xxx.xxx.177.0

network xxxx.9.61.0

network xxx.9.62.0

network xxx.2.89.0

exit-address-family

I dont have access of my ustream provider router.

Thanx.

Harold Ritter · ‎09-13-2005

Is it possible that the distribute-list applied outbound toward the SP could be blocking the advertisement of these prefixes.

Hope this helps,

Regards,
Harold Ritter, CCIE #4168 (EI, SP)

attrgautam · ‎09-13-2005

Can you check the status of your BGP ? Whether you are able to advertise any routes and able to receive any ? Also can u print your prefix/distribute lists?

gaurav_saxena · ‎09-13-2005

Hi Shahzad,

As per thumb rule of BGP, for a prefix to advertise via EBGP, there should be a exact match route for that prefix in IGP routing table.Which IGP you are using?

gaurav_saxena · ‎09-13-2005

I afraid i read this query completely..Please igone my answer for this query.

shahzad.rasheed · ‎09-13-2005

thanks a lot to every one who contirbuted ... problem is resolved and it was distrbute list :$.