Networks

When you say VM, do you mean VMware ESX?

Normally you would have multiple NICs that plug from the switch into the VMware server, and from a 'failover' perspective, there is nothing to configure, as the second NIC just sorta works.

True load balancing is a more complex thing...it's either done in the server OS, in a load-balancer appliance, or even in a router.

Realistically you don't need to load-balance between multiple NICs going into the same switch, as it's not typical that you would have enough traffic to overload one NIC. If you do need to do actual VMware load balancing, that is done by vSphere and/or a load-balancing virtual appliance.

And, of course, the connection between the Ethernet switch and the server is probably not the slowest link in the chain, typically there may be a router or WAN between the server and the users, thus 'where' you load balance is a bigger question.

Then the final question is what application you are load balancing, as the requirements and techniques are very different for a web application versus a database, for example.