Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

New Member

Can a single VLAN exist across multiple sites ?

Is it technically possible to have a single subnet as a VLAN exist across multiple sites. We currently have our WAN setup to use Frame Relay but are looking to move to a private IP VPN (MPLS) based solution. In either scenario can, say, a single class C address range, set up as VLANXX, exist in more than one interconnected site without being subnetted ? If specific hardware/software is required please advise.

A pretty sketchy question I know - but any response appreciated.

New Member

Re: Can a single VLAN exist across multiple sites ?

with the amount of traffic flowing across a trunk,

I wouldn't do it. The exception being Multiple Elans over an ATM fabric

New Member

Re: Can a single VLAN exist across multiple sites ?

I've had the VLAN exist at 2 different sites

(about 6 miles apart), but it was only a temporary solution, because the company was moving from one location to the other and needed 24/7 uptime and could not change their IP addressing at the new location due to bad code (duh!). I have a full T-3 between the 2 buildings and was bridging those VLANs accross the WAN. It was a hairy configuration, but I pulled it off and it worked...and I got thanked by the CIO!! Not recommended though! :)

Good luck