Greetings all,

We have been tasked to configure a series of DELL 6224 switches to operate in large simulation environment.  In essence, all switches have 3 VLANS,  VLAN1, VLAN2 and VLAN3.  VLAN 1 has been left alone to remain as the management VLAN although the majortity of the ports have been assigned to VLAN2 and 3.

When connected in isolation (Switch 1 VLAN2 to Switch2 VLAN2 to Switch3 VLAN2 etc) all ports connected to the VLAN can be pinged without difficulty. Connections between VLANS are made using an Access port.

The diagram below illustrates what we are hoping to achieve..

Things go pear-shaped when ports between VLAN3 on each switch are connected.  As  soon as a pair of ports on VLAN3 are connected, comms across VLAN2 ceases. 

Looking at other posts, it would appear Spanning Tree issues could be behind this but I do not understand why.  The devices connected to VLAN2 and VLAN3 are on a different subnet so ethernet loops should not be an issue.

Some insight into VLANs and Spanning Tree would be appreciated!

 

Thanks

 

Steve