Question : Problem: VLANs, questions from a complete beginner...

I have been trying to learn about VLANs, and have started to try and apply what I know to my network.

I have two Linksys SRW208G switches which I want to put on a separate VLAN to improve performance and separate those computers on the two switches.

The Linksys switches uplink to a 3Com 4400SE switch, which in turn uplinks to the backbone 3Com 4924.

On the 4924 I've created a second VLAN and tagged the uplinked port from the 4400 in both VLAN 1 & VLAN 2.

On the 4400 I've created a second VLAN and tagged the two uplinked ports from the Linksys switches, and the uplink port to the 4924 in both VLAN 1 and VLAN 2.

On the Linksys switches I think (because the interface isn't great) I've told the ports on the switch e1-e8 to be untagged in VLAN 2 and I've set the g1 uplink port as trunk, tagged in VLAN 2.

The problem is that this doesn't work!!  I am on a computer in the default VLAN 1 and cannot communicate with either the Linksys switches or any of the computers attached to them, but I can communicate with the 4400 and all the other devices connected to it in VLAN 1.

Help?  Do I have to tell the 4924 to route traffic between the two VLANS?  I thought that a port being tagged in more than one VLAN would do that already on a Layer 3 switch?  Is the problem between the Linksys/3Com switches?  

Answer : Problem: VLANs, questions from a complete beginner...

I am speaking from a totally cisco background, so I'll try to relate.  You may need to turn on the layer 3 functionality of that switch, I know the ciscos do not have that enabled by default so it may be the same with other vendors.

It also does sound like you may have some inter switch problems too.  Sounds like you need some trunk ports between the switches.  The purpose of these ports is to carry multiple VLAN information across multiple switches.  You might want to check out 802.1q encapsulation as it relates to your switch vendors.  Without this trunking your uplinks only carry single VLAN data.