Layer 3 forwarding in Nexus 7000

[msmoon]

Hi there!

I heard from Cisco PH about Layer 3 packet forwarding on N7K.

Functions of N7K's supervisor are very similar with those of MSFC on C6500 sup 720.

and L3 packet forwarding is performed by M1 series module.

An F1 series module(even though we have only one model now) perform L3 packet forwarding by forwarding packets to M1 modules.

If I have 3 M1 modules and 2 F1 modules on my N7K, which F1 module forward its packet to which M1 module?

What happen when F1 module wants to do L3 forwarding?

[Chad Peterson]

You are correct in this.

The F1 module is incapable of performing L3 rewrites itself, so it has to offload this function to another linecard...so in this case an M1 module.  If you have multiple M1 modules it will load-balace between them for this function.

If you have no M1 modules in your system, then your Nexus 7000 will only be able to perform as a L2 switch.

I hope that helps clear itup.

Chad

[msmoon]

Thanks for your answer.

Actually, M1 modules capacity are 80Gbps but F1 is 230Gbps.

If forwarded packets are load balanced to M1 moduls,

then isn't there any performance issue?

for example, one M1 series module and 2 or 3 or more F1 series...

and weighted load balancing? or per host based load balancing? what would be?

sorry for having too many question...;-)