v-lans vs. subnetting

techgeek07

Alright, to be honest, they seem to have alot of similarities in the fact that they both are used to break up a network. Would someone mind breaking them down in english (as in when to use which, what the differences actually are, and so on)?

Webmaster

Check out my Network+ TechNotes for a very basic overview of VLANs (Switches section)
www.techexams.net/technotes/networkplus/networkcomponents.shtml

But comparing vlans to subnet is a bit like comparing apples to oranges. From the perspective of subnetting (layer 3), a VLAN and physical LAN are the same. Using VLANs is basically a means of creating separate LANs (on layer 2) without the need for additional physical devices (ie. multiple virtual LANs on a single physical switch).

Cisco does recommend a one-on-one relationship for subnets and VLANs. Meaning each VLAN gets it's own subnet (where subnet can be major/classful network or subnetted network).