BGP STUCK BUT NEIGBOUR IS UP

[daniel81092]

Hi guys,

Two router are connected CE TO PE

i can see neighbour IN PE OF CE but BGP session between them are still active

NOTE:- between CE and PE we  have carrier link and all the test from carrier are good and clean

any possibility of correctness

[Georg Pauwen]

Hello,

post the running configs of both routers, as well as the output of:

sh ip bgp neighbor

[daniel81092]

BGP are active state 

configration are basic BGP

[daniel81092]

for vitrual interface

encapu do1q

vrf forwar

ip address

same both for PE and CE

[Reza Sharifi]

Hi,

i can see neighbour IN PE OF CE but BGP session between them are still active

Do you have basic layer-3 connectivity? Can the CE ping PE and vice versa?

HTH

[daniel81092]

No i am not able to reach CE to PE and VV via ping but i can see in CDP neighbour in PE that CE is available''

only BGP  is active

[Reza Sharifi]

So, before you get to BGP, you need to establish layer-3 connectivity between the 2 devices first. Do both sides have IPs?

Can you post the config? Is the interface in up and up mode?

HTH

[daniel81092]

interface are up and even in cdp neigbour i can see both CE to PE and PE to CE

[Reza Sharifi]

cdp neigbour is just layer-2 and does not mean BGP will work because you see the neighbor. The first thing you need to figure out is why you are not able to ping the peer IP address. Layer-3 connectivity must be established first.

HTH

[daniel81092]

layer 3 are up as i checked the route with show ip route i get the route for directy connected via TE inteface

a

[paul driver]

Hello

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@daniel81092 wrote:

i can see neighbour IN PE OF CE but BGP session between them are still active

NOTE:- between CE and PE we  have carrier link and all the test from carrier are good and clean

any possibility of correctness

---

If you are using default route for the ebgp peering then it wont come up, As rtr will perform a route lookup and if it only has a default route for peering it will ignore it, even though it can peer that potential peer..