Etherchannel

vmware - hp procurve lacp / trunk

Cisco’s Etherchannel and HP’s LACP are very similar – probably why I assumed both are supported by vmware. But as per below – it is not the case.

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1004048

From a procurve perspective the differences between a “trunk” and “static lacp” trunk is the total bandwidth per connection. A typical end point on a “trunk” trunk can transmit various connections down both pipes, but only receive down one – sometimes refered to as TLB (transmit load balancing). In vmwares case when you are using a “trunk” trunk you will have ip hash set as a load balancer, effectively meaning a different nic will be used on the vmware side for each connection a virtual machine makes.

ESX - network utilization

One of the best articles i have found on this subject is here : http://blog.scottlowe.org/2008/07/16/understanding-nic-utilization-in-vmware-esx/

There is some additional information here on setting up an etherchannel on the cisco side : http://blog.scottlowe.org/2006/12/04/esx-server-nic-teaming-and-vlan-trunking/

This can be handy if you need a single VM to use both physical nics in a load-balanced manner - both outbound and inbound. Of course its not really that simple though. This will really only add a benefit if the VM is communicating to multiple destinations (using ip hash - a single destination from a single VM with one IP will always be limited to the same physical nic).