BGP

[pnkjmalik11]

Hi There,

Question 1 : We have two router on both router BGP is running. Client called and said BGP is flapping on Primary router Why ?
And he said kindly shift my traffic to secondary router, how we can do that in real environment?

Question 2 : We have advertised the customer prefixes in BGP and when we logged in Customer Premises device we were not getting the routes.

kindly share the possible reasons and resolutions.

[balaji.bandi]

we are not sure how these connected and is this links both go to same ISP ? same BGP

we need more information how your network connected between network and rest of the network. to identify the issue, Logs ?

Look below document :

https://www.cisco.com/c/en/us/support/docs/ip/border-gateway-protocol-bgp/23675-27.html

[Georg Pauwen]

Hello,

local preference is typically used to determine the exit point...

Post the full running configs of both routers...

[Giuseppe Larosa]

Hello @pnkjmalik11,

>> Question 1 : We have two router on both router BGP is running. Client called and said BGP is flapping on Primary router Why ?

one possible reason for BGP flapping is traffic saturation (too much user traffic) if no QoS is applied to protect the BGP sessions packets.

>> And he said kindly shift my traffic to secondary router, how we can do that in real environment?

You can increase local preference from standard value of 100 to an higher value of 300 on your secondary router referring to the eBGP neighbor.

>> Question 2 : We have advertised the customer prefixes in BGP and when we logged in Customer Premises device we were not getting the routes.

not enough info here.

use show ip bgp siummary on the CPE to see the status of the eBGP session it has to be estalished a state of Active is no good.

post the output here.

if the customer has two sites and it is using the same AS number it needs

neighbor  <your-router> allowas-in

to accept an eBGP with AS path that already contains its own AS number

Hope to help

Giuseppe