Question : setup a VLAN

is there any software to download to configure a VLAN.

I have seen in hp network configuration utility properties a button that says VLAN(802.1q).

is this to ocnfigure VLAN.
I didn't use, because I am not sure if it would mess the configuration or not.

Answer : setup a VLAN

I'll try.  

Imagine a LAN as a office with a long hallway.  This is a MAC level broadcast.  If I want to talk to somebody I yell "Hey Bill" and then Bill says "What" and we talk.  If I want to broadcast I say "Hey Everybody!" and everybody listens.

A bridge/switch will allow two hallways that are on different floors to appear as one long hallway.  It will transparently relay messages from one hallway to another.

Now imagine one real long hallway with lots of people.  A VLAN would be if I put in should proof walls at certain points in the long hallway that created smaller hallways.  So even though it is one hallway, it appears to be multiple short ones and people in one part of the hallway can't hear people in another part.  They don't know that there is even another part of the hallway.

Now to go just a step further to get IP in there.  Imagine that the layer 2 protocols was "English" and that the layer 3 protocols ("IP") used different languages for each subnet.  Subnet #1 used French and Subnet #2 used Spanish.

Now pretend that we have one IP subnet right now, and we will use French.  With a single hallway I would still yell "Hey Bill!", but once I got Bill's attention I would deliver the message in French.

Now we have two hallways with a bridge/switch.  I still use English to get peoples attention and French to deliver the message.

Now we have two hallways with a router and so I have two IP subnet's.  I still use English on each hallway to get peoples attention on each floor, but the people for floor#1 use French to deliver messages and people on floor#2 use Spanish.  The router will translate between the two languages and this is NOT done transparently, everbody know that if they want to talk to one of the "Spanish" groups, they need to send the message through the router.  The people for floor 1 will only ever hear English and French and the people on floor 2 will only ever hear English and Spanish.  However the English from one floor will NEVER be heard on the other floor.

Now say you have one long hallway that you logically divide up into to separate IP subnets (VLAN's).  I still use English to gain everybody attention, but one group of people will only speak French and one group Spanish.  However because they are all in the same hallway they all will still hear each other.  Just the French group will ignore the Spanish messages and the Spanish group will ignore the French messages.  And they can't talk to each other without a router.

Does this make any sense?  It not really how it works, but it is the best I can come up with right now.