vPC ESXi

[Dragomir]

WE got our ESXi servers recently moved from a 6513 to nexus 2000 FEXs uplinked to a nexus 5000s

basicall we have enhanced vPC and nics goin to 2 different FEXs and they uplink to 2 nexus 5000.

the Vswitch for VMs is setup in a VPC.

Question is do the traffic from each vm going in/out of these nics in a vpc actually use both physical links? How can i tell from the switch?

[Reza Sharifi]

Yes, the traffic should be load balance based on the source-destination IP.  So if the traffic is coming from 2 different IPs, one should use one link and the other one the other link.

You can also check with this command to see which path the packet is taking.

show port-channel load-balance forwarding-path interface po1001 Vlan xx Src-ip

HTH

[Dragomir]

so if I have a vm on a vswitch that I move a file out of the vm to another location, should the traffic be ssplit across 2 fexs to 2 different nexus 5000?

Or will it go through only on 1 link? If it goes through only  link, what is the purpose of the vpc for?

also vice versa, if I copy files from a emote location into this vm on this vswitch, will the incoming traffic be split across to fexs?

[Reza Sharifi]

so if I have a vm on a vswitch that I move a file out of the vm to  another location, should the traffic be ssplit across 2 fexs to 2  different nexus 5000?

Correct, if you have 2 vms and each vm has its own ip, the traffic will load balance across multiple FEX links.

[Dragomir]

what about 1 vm, would it utilized only 1 physical  nic outbound/inbound?

[sajid_m123]

I guess it depends upong the LoadBalancing mechanism.

For an ESX switch: If IP hash is used then it would depend upon the final hash result.

If Port based is used then it would take its mechanism to choose the physical NIC.

You may calculate manually if like and verify.

[shijogeorge]

A single session can utilize only one member port in the port-channel.

So if you do a file copy from say VM A to location B, that will utilize only one physical NIC.

But a file copy from VM A to location C at the same time might utilize other physical NIC.

HTH

Shijo George

[Dragomir]

sh port-channel summary shows y port channels do not have lacp enabled.

do I need this?

[sajid_m123]

in order to verify loadbalancing, you don't need this.