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New Member

Catalyst 2950 and Foundry Bigiron 8000 (VLAN)

Hello- I've got a Foundry BigIron 8000 switch at the core (inherited), that is configured with two VLANs ((1) Engineering and (2) Lab). I've connected a stack of Catalyst 2950s to it that only serves clients on the Engineering VLAN and that works fine.

I now need to connect another 2950 that connects clients on both the Lab and Engineering VLANs. Currently, I can only get the ports on the new 2950 to allow Lab VLAN clients. How do I configure this to allow clients for both VLANs? I'm going to set the ports to static, they don't need to be dynamic.

I've attached a diagram here.



New Member

Re: Catalyst 2950 and Foundry Bigiron 8000 (VLAN)

Well, there's the obvious stuff, like connecting the crossover port from the 2950 to a trunk port on one of the other Cisco switches and make sure that you have connectivity. And make sure that the ethernet configuration of both VLAN1 and VLAN2 on the Foundry both show the appropriate ethernet port being in the 'tagged' state.

ie. 'tagged ethernet 1/1'

Also, make sure the trunking mode on the Cisco switch is set to 802.1q and hardcoded to be a trunkport. Also, don't make use of 'switchport trunk native vlan' or 'switchport access vlan' at all.

I've found trunking between a BigIron and a Cisco to be a little touch-and-go.

= K


Re: Catalyst 2950 and Foundry Bigiron 8000 (VLAN)

The Foundry port that the Cisco is uplinked to is set to tagged for both VLAN 1 and 2. As far as the trunking port on the Cisco, it is as follows:

Admin Mode: 802.1Q Trunk

Trunk Allowed VLANs: ALL

Pruning VLANs: 2-1001

Native VLAN: 1


Re: Catalyst 2950 and Foundry Bigiron 8000 (VLAN)

OK, I called Cisco tech support and got the answer. It seems that Cisco switches support a concept of Native VLANs and Foundry does not. So, the frames weren't being tagged on the Cisco but were on the Foundry. The tech had me create a new, empty VLAN on the Cisco (VLAN 3) and make that the native VLAN on the trunk port. Once I did that, evrything worked as expected.

New Member

Re: Catalyst 2950 and Foundry Bigiron 8000 (VLAN)

Glad to hear you got it working. I did ask you to make sure though that you weren't using a native VLAN on the Cisco switch though. :)

Hope the TAC call didn't cost you anything. :P

= K

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