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New Member

OSPF & dot1q Trunking



The black lines between the devices are wireless bridges.

I need to create a trunk between switch 1 and switch 2 so I can pass vlans through. I currently have ospf running on both switches as well as the linux router with a network of If I create a trunk between 1 and 2 will the linux ospf router still be able to connect to the other switches via ospf or will the trunk disable it from seeing the other switches?

I really don't want to put a 3550 in the location where the standard switch is because its in an outdoor cabinet at the bottom of a tower in a harsh enviroment.




Re: OSPF & dot1q Trunking


Theoretically there is no problem that i can forsee in this setup.

As per you diagram all the devices ( switch 1, switch2, linux) are on the same subnet.

Hence, they will have reachability between them as long as you dont break up the segment(vlan) on which they reside.

Just remember that when you enable trunking on Switch1 and Switch2, the "standard 10/100 switch" should also be configured for trunking. Especially the ports through which the switch1 and switch2 gets connected to the "standard 10/100 switch".

Hope this helps


New Member

Re: OSPF & dot1q Trunking

The standard switch in the center does not support trunking. I'm assuming that this setup will not work then?

Re: OSPF & dot1q Trunking

Yes. You are correct. If that switch doesn't support trunking then you cannot extended the vlans from switch1 to switch2.


New Member

Re: OSPF & dot1q Trunking

Ok, So if I had a 2950 switch in place of the "standard switch" so I could do trunking between switch 1 and 2. What type of configuration would I have on the 3550's in order to maintain the ospf to the linux router?