While some people prefer more "sophisticated" methods of virtualization, I have been quite happy with OpenVZ.
This is what the commercial platform Virtuozzo uses as its core to manage VM instances.
When working with OpenVZ instances or "containers" I often use the link below as my reference.
This is a very good guide on how to do everything OpenVZ from the command-line interface
While I am quite partial to Cisco, sometimes I must work on foundry equipment.
The command interface is very similar to Cisco's although some of the commands differentiate enough to make it a pain..
Below are two links I find quite useful when trying to manage Foundry equipment.
http://garretthoneycutt.com/index.php/Foundry
http://www.codealias.info/technotes/vlans_with_foundry_switches
If you are running cPanel or Plesk on your server, adding a range of IPs is simple.
But, what if you are not using a control panel and need to add numerous IPs?
Instead of creating a new interface for each address, RHEL-based systems allow you to specify a range of IPs to use.
Further details can be found at: