I am having a challenge adding a third HP 2910al switch to our existing configuration of two switches. This I thought should not be a great challenge based on my experience with Cisco switches, wrong.
Currently we have two switches one that I will call Gateway as this has the connection to our VLAN to MPLS to the outside world, all inbound and outbound traffic goes through this switch. The second switch is just that a switch with trunk ports tied to the Gateway switch.
The switches have two VLANs in common VLAN1 10.1.1.0/24 for data and VLAN10 192.168.96.0/24 for voice with our Avaya IP system. The switched are connected by one trunk port on each for VLAN1 and another trunk port on each for VLAN10. This configuration has been in place and working for years
Now I need to add a third switch with VLAN1 and VLAN10 to this configuration. My thinking which is obviously incorrect was to add a set of trunk ports for VLAN1 and VLAN10 on the new switch as the others have. I then added another set of ports for VLAN1 and VLAN10 to the gateway switch and connected the switches. Bad results
I must be creating a network loop in the switches when I connect the third switch as both VLAN1 and VLAN10 no longer function.
Obviously I am missing something or not understanding the concept of trunking with the HP switches. Any guidance would be appreciated