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New Member

6506 & 3550 Layer 3 switches

My current network consists of a 6506 with MSFC2 in the core and 35xx series switches in all the closet. I don't have a true distribution layer, just the access layer and the 6506 in the core, along with all the servers. I currently have one VTP domain managing the existing switches. However, we are adding a new building to our network, which will consist of a 3550-12G with EMI in its MDF, and more 35xx series switches in the closets. The 3550 will connect back to our 6506 directly via SM fiber for access to various server based resources.

So, my question is, do I need to create a new VTP domain with the 3550 as its server (since we have a layer 3 boundary here), or is there a way to integrate the 3550 into our current domain?

I tried integrating it into our existing domain, and it didn't work properly. If it will work, I'm sure I screwed up the configuration, and couldn't "see the forest for the trees". Thanks in advance for any advice.

Cisco Employee

Re: 6506 & 3550 Layer 3 switches

3550 can act as a layer 2 switch as well. You can configure the interface connecting to the 6506 as a trunk and have the same VTP domain across your network. You can find more on 3550 configurations on CCO at

New Member

Re: 6506 & 3550 Layer 3 switches

I would like to utilize the layer 3 function of the 3550 if possible. If I keep it configured as a layer 3 switch, am I stuck creating 2 VTP domains? If so, this is what I will do. It is not a problem, I was just wondering if there was a way to do it, to make management as easy as possible. Thanks for the help.

Re: 6506 & 3550 Layer 3 switches

Edward, It shouldnt be a problem at all. Its always better to use a single domain, unless its needed due to some reason.

You can configure the same domain, and still use the 3550 as a layer 3 switch. VTP works at layer 2 and is designed to work transparent to layer 3. So you can have the layer 3 functionality at the 3550.

THis 3550 will route for all vlans associated with your 35xx (at closets) in the new building. The MSFC2 will route for all the vlans associated with the 3550s in the old building. Some routing protocol (such as EIGRP) should be configured in both the MSFC2 and the 3550 (layer 3 switch in the new building) to exchange these routes, so that routing will take place. Still you can add all of them in the same VTP domain.

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