Can I have an extended LAN over WAN?

[cquiroz]

Hello Community! 

I was wondering if I can have layer 2 traffic over a layer 3. 

Let me elaborate. 

I have a site A that has two servers working as a cluster. My client wants to replicate this cluster into another site that they have. The problem is that this cluster is using an IP address located in Site A and, when it switches, it brings the IP configured on the interfaces. Site B does not have this addressing whatsoever.  

These two sites connect via VPN. I know that layer 3 cannot have duplicates subnets because we can face issues of overlapping. I have little knowledge about "Extended LAN" that is basically a trick to have layer 2 traffic over layer 3 traffic, so when a servers wants to do a ping, it can reach it. 

SITE A - 10.10.10.0/24 - FW ===== VPN ====== FW - SITE B 10.10.10.0/24

What is the configuration that I should be looking into?

[balaji.bandi]

I go with Layer 2 Tunnel. ( what FW you have both the side ?)

example :

https://www.cisco.com/c/en/us/support/docs/ip/layer-two-tunnel-protocol-l2tp/116266-configure-l2-00.html

[cquiroz]

Good day!

Thanks for your reply. I was Validating this configuration before but it got me wondering. We have a Sophos Firewall on one end and a Cisco Firepower on the other end. Is this configuration possible using third-party devices?

[balaji.bandi]

yes This is standard requiirement -  any FW should support this feature, check the FW feature guide

[cquiroz · Accepted solution]

Hello! Thanks a lot for you help. 

I was able to understand a little bit more the requirement. I needed a service of Pseudowire or VPLS from the ISP so I can extend my LAN. 

I'm gonna  close the topic now. Thanks a lot!