That's excellent, thanks. I want to support the rating scheme but all that i see is reply and email this message. How do i rate posts? Also does that mean if i wanted to configure all 24/48 ports on a single switch they would all have to be in different subnets?

Look for Rate This Post to the right :-)

You can configure the switch to support VLANs. Type 'show vlan; and it will show you what VLANs are configured and what ports are in which VLAN.

To create a new vlan:

Switch(config)# vlan 5

Switch(config-vlan)#exit

If you want to add a port to VLAN 5:

Switch(config)#interface fa0/1

Switch(config-if)#switchport access vlan 5

Look at the VLANs again (show vlan) and you should now see vlan 5 with port fa0/1 as a member. Now if you wanted the switch to be the layer 3 gateway you would configure a vlan interface (SVI). You must have a layer 3 image on the switch to do this.

Switch(config)# interface vlan 5

Switch(config-if)#ip address 192.168.5.254 255.255.255.0

HTH

I know that this sounds stupid but "rate this post" doesn't appear on my web-page. I've even enrolled one of my colleagues to come and have a look with me (to make sure i'm not going blind!) - it's just not there! All i see at the bottom is reply and email this message, the right of the screen is just blank. Please help - i think you deserve to be rated :)

You said:

if you wanted the switch to be the layer 3 gateway you would configure a vlan interface (SVI). You must have a layer 3 image on the switch to do this.

Is this just enabling the pc's on vlan 5 to communicate with each other without accessing the router or has it got a higher purpose? I thought that they'd be able to ping each other anyway as they're all in the same vlan.

If you multiple PC's in the same VLAN (lets say vlan 5) they can ping each other without the gateway configured. Let's say you add another vlan (lets say vlan 6) and you want the PC's on VLAN 5 to talk to the PCs on VLAN 6, then you would have to configure the gateway on the switch for the PC's. It just provides a way for the PCs to get off their local LAN (vlan 5) and be able to talk to devices on other LANs (such as vlan 6). Does that make sense?

I wish i could rate you!! Every thing that you say and the way you explain it makes perfect sense. I'm making you a favourite!! Oh wait up, there's no favourite button either.....

I wish i could rate you!! Every thing that you say and the way you explain it makes perfect sense. I'm making you a favourite!! Oh wait up, there's no favourite button either.....

Does this mean though that i would have to then place an access list on the relevant router (if for example there were more than one vlan on the switch) if i wanted to only enable vlan's 5 and 6 to communicate but not vlan 7 or would i just not set the ip address on the switch as the default gateway. This would then mean that vlan 7 is not communicating through layer 3 switching and would have to pass traffic through the router. Correct?

If you did not want vlan 7 to talk to vlan 5 & 6 ,but you did want to allow it to vlan 9, then you would need the access-list. If vlan 7 never need to talk to any other vlan, then you would not need to configure a gateway for that vlan. Layer 3 switching (the SVI) is the router! When we create that layer 3 SVI interface, were enabling a virtual routing interface. If we create 5 vlans with 5 SVI's, we've create 5 virtual routing interfaces. It's just like if we had a router that had 5 ethernet interfaces. As you can see, layer 3 switching is a very cool thing and saves us having to buy lots of routers and router interfaces.

SVI: Switch Virtual Interface