Server Fault is a question and answer site for system and network administrators. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

We have two sites (essentially two small buildings side by side but we are unable to run CAT5 cable between them) which are currently linked via a wireless bridge. We will be splitting the sites so they are more independent, i.e a DHCP scope per site, and a WAN connection per site (rather than now everything from Site B routing over the bridge to the default gateway in SiteA).

Site A
Site B

How can you setup a wireless bridge between two sites where the subnets are different in each site? This is on the assumption each site will have a firewall like a Sonicwall (with 4 LAN/WAN interfaces) capable of doing the routing that would be required, but it's the routing that would be required I am failing to quite grasp.

I appreciate in this above situation we could simply setup a Site-to-Site VPN connection but we want to keep the wireless bridge in place between the Sonic's in the scenario the WAN link goes down and either end.

share|improve this question
Treat the site-to-site wireless link as if it was a wire and ignore it. You don't bridge any more. You setup routing on the Sonicwalls. – Zoredache Aug 1 '13 at 18:41
Conceptually, what sort of routing would need to be put in place on either end though? Say, what IP addresses would you give the wireless AP doing the bridging on either end? – PnP Aug 1 '13 at 18:42
Well, if you don't care about accessing the APs, then you wouldn't need to give them an IP at all. Just treat them like they are layer 2 and ignore them. But you will need to setup another subnet for that site-to-site link anyway, so you add a subnet, and configure the wireless devices, to be on that network. – Zoredache Aug 1 '13 at 18:51
Right, so for example, I could setup say, place the APs on this network, then on each Sonicwall, let's say that above network is on interface X3, setup routes, on SiteA sonic, anything for SiteB Subnet route to X3, and vice versa at SiteB. – PnP Aug 1 '13 at 18:52

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Browse other questions tagged or ask your own question.