Layer 3 Port-channel between Cisco 6500 and Nexus 7k

[Nirmal Singh]

Hi,

Currently, I have Layer 3 routed links between a pair of Cisco 6513 switches and a pair of Nexus 7k switches (see diagram below). The Nexus and 6513 are running BGP between them, and iBGP among themselves (Nexus and Nexus, 6513 and 6513).

Recently, the routing links are getting quite saturated and it's been suggested to increase the bandwidth, by forming Layer 3 ports channels and applying an appropriate load balancing algorithm (such as src-dest-ip). 

I know that the Nexus use vPC as Layer 2 port-channels only, but not Layer 3. If I am going to run normal Layer 3 port-channels between this devices, is there any gotcha's that I need to be aware of? 

Also, what's the best way to migrate them to Layer 3 port channels with minimal downtime?

Thanks

[InayathUlla Sharieff]

Please do not do this kind of changes without the downtime.

The below layer 3 ether channels set-up which you have showed looks good to me.

Kindly prepare the config for the ports.

Shut down the ports, Create the port-channel first at both the ends.

Map  the port-channel config on the individual ports and then bring the ports bck online. this is just my preference but you can do the config when the ports are in up state as well.

HTH

[Nirmal Singh]

Yes, a downtime is scheduled for this. 

Is there going to be any interruption to the load balancing algorithm if I change it from it's default src-dest-mac to src-dest-ip? There are currently many port channels formed on the 6513 switches to other switches and servers.

[InayathUlla Sharieff]

No there wont be any interuption.

The next packet hitting the switch will use the changed lb algorithm.

REgards

Inayath