Showing results for 
Search instead for 
Did you mean: 

Extending VLANs across a L3 connection to Remote Site

Terence Lockette

Hey all,


I have a unique request from our server admin who wants to add some servers at our remote site but would like to have them on our VLAN 1 so that he replicate and have them for redundancy.  Currently, we have a 100Mbps fiber link connecting both sides with 2911 routers at both ends that establish the layer 3 link.  I've heard about EoMPLS and VPLS as well as L2TPv3 but I'm not sure what to do or where to even begin.  Ask any questions and I'll provide you with the best answer or info you need.  Thanks!

5 Replies 5

Hi tlockett

This is a typical request from the server guys as it's simple for them and complex for you to sort safely. VPLS is not an option on the 2911 so that's out of the question. 

Do your 2911 have spare routed interfaces that you could use to connect using l2tpv3? If they do that Will be your simplest solution. However be aware that this is not a scalable. Also the performance when running l2tpv3 will take a hit as the router will have to encapsulate the frames, this is a problem at small packet sizes and not ideal. This may also be a limiting factor on the performance of any backup solution run over the connection. 

Worst case the volume of replication traffic could hammer the router and put it at risk. 

Before you do it check with the server guys how much bandwidth will be required under both normal and failed conditions and make sure the router has the capacity to deal with it. 

Meanwhile it may be an idea to encourage them to explore backup solutions that support L3 clustering, automation of gateway switching, possible some clever DNS  solutions could help. Pretty much any solution other than l2tpv3. 

Sorry not to be more positive but at least you have options. 



Hello Lex,

I agree and performance and bandwidth consumption were my main concerns.  I'll forward this info over to my server guy and see what he thinks.  I'm also looking at some alternative solutions that won't involve L3 routing to achieve extending the VLAN.  My thought is since our fiber link is a L2 connection, I can have our provider trunk the link while I prune off VLANs.  Since our remote site has it's own subnet on VLAN 1, I can put them on a different VLAN while keeping our servers at this location on VLAN 1.  Does that sound doable?

That sounds like a much better plan. Also probably more resilient and leaves the responsibility for transport with the ISP where it belongs. 

Good luck with it. 

Thank you!

No problem. 

I hope it has helped and if you think it has please take a second to rate my response or mark as answered. 

Good luck with it. 


Getting Started

Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community:

Recognize Your Peers