Port channel Setup

[vinayak-nayak]

Hi All,

Is there a method to add an additional ten gig link to an in-production 10 gig link to form a port channel. 

The catch here is that the 10 gig in-production link is a routed port having a L3 ip and the other end too is routed port and both these have BGP peering sharing routes. I need to use the existing routed port ip address on either ends of the port-channel to be built, thus it will be L3 port channel consisting of the in-production and new 10 gig links. note : (I cannot change the entire config but only need to add a new dark fiber and make it a L3 port channel using the existing ip on the in production routed port). Diagram given below for reference. Is there a way to do it without having any downtime or impact ? Pls guide.

[Philip D'Ath · Accepted solution]

No, because you'll need to remove the IP address from the physical interface and then re-apply it to the Port-Channel interface.  That will cause the path to go down.

I would schedule in a time, shut down the BGP peer, form the port-channel with its layer 3 configuration (obviously on both ends) and then bring the BGP peer back up again.

[vinayak-nayak]

Thank you !

[vinayak-nayak]

Hi, 

I missed mentioning a point here. There is only one single link between these two sites, therefore when i shut BGP then i would lose access to one site right ? The other site has a default route pointing to site A. 

Also i think i would need to shut the physical interfaces and then apply config and assign them under port-channel and bring them up. But this would need to be done on both sites simultaneously right ?

Would these steps be fine ?

> backup the config

> graceful shut of the bgp peer

> no ip address on both ports

> create port-channel

> assign both ports under it

> apply previous ip address on port-channel

> no shut the port-channel and observe it to come up

> unshut BGP peering and check bgp neighborship build

> check for internet and intranet access