extending a vlan through a layer 3 connection

[karthikeyan gopinathan]

Hi

in our environment we have a 6509E as a core switch which is connected to five 3750G installed in remote sites and are layer 3 routes. the routing protocol is ospf. i am just wondering if we could possbily create a vlan in the core switch and extended it to the remote site throug layer 3 connection. The reason we are thinking to do this we want to have a server redundancy if one of the server goes in the core site we can just turn on the server which is in the same vlan in the remote site so that we can limit the downtime ..i am trying to brainstorm this idea.. please let me know if this is possible and also send some suggestions to do this.

[blau grana]

Hi

if you run MPLS between core and remote site you can contigure xconnect to extend vlan.

or if you do not run, you can configure pweudowire with l2tp encapsulation to do the same but without underlying mpls

Best Regards

Please rate helpful posts

[karthikeyan gopinathan]

can we do this configuration on a internal network. i think mpls or pseudowire is for external networks

[blau grana]

Hi

I am not aware of any reason why you could not use mpls or pseudowire in your network.

What exactly do you mean by "external" network?

Best Regards

Please rate helpful posts

[Giuseppe Larosa]

Hello Karthikeyan,

your devices are multilayer switches C6500 and C3750G, I don't think MPLS is  supported on C3750G. C6500 can support it with Sup720 3B or better. So I would say an EoMPLS xconnect is not possible.

Besides this, EoMPLS or L2TPv3 pseudowire are point to point in nature. You would multiple pseudowires from HQ to each branch,.

I don't think C3705G support L2TPv3 too. Again C6500 can support it.

Or you change each link between C6500 and remote 3750G devices in layer 2 802.1Q trunks carrying muliple Vlans and using SVis for L3 routing, or you have to give up with this idea of extending Vlans over your current network.

That is probably the best move.

Hope to help

Giuseppe