Layer-2 Bridge between locations on same subnet for disaster recovery - Can this be done?

We currently have a network connection between two locations over a two-hop 802.11 2.4 GHz. radio link. The two locations do not have line of sight. Both locations are on the same sub-net. The radio links are encrypted and configured as a layer-2 bridge. The locations behave as if they are on the same LAN. I have been asked to come up with a disaster recovery plan in case the radio tower at the central hub location falls-over or is damaged due to a weather event.

Is it possible to configure an RV55, RV50, or LX40 or similar radio to act as a layer-2 bridge between the locations as a backup. Presumably the radios would have static WAN IPs. The radios need to establish an encrypted point-to-point connection. There is no requirement for these radios to act as WAN gateways or as an Internet gateway fail-over. Re-assigning the location to use different sub-nets while not impossible is not desirable. The goal is for cellular radios to have similar functionality as the 802.11 radios during the period while the radio tower is rebuilt.

My question is whether this arrangement is possible using the Sierra radios? If so what radio can accomplish this? If this cannot be done as described, can anyone suggest an alternative?

My apology if this question has been asked and answers. My searches on the subject were not fruitful.

Hi orlofsky,

It’s hard to figure out what you describe. To simplify it, could you please draw a simple network topology for this case?


Current 801.11 radio link between location A and B acting as a layer-2 bridge.

Proposed cellular radio link between locations A and B. Drop in replacement without renumbering LAN addresses in Location A or B.

Hi orlofsky,

In picture 2, you need to configure a VPN server between 2 RVxx Cellular modules for security. In this case, one public IP for the VPN server is enough.

If you want the system in picture 2 to work as a backup for the one in picture 1, RVxx modem also supports VRRP (Virtual Router Redundancy Protocol). In this case, the device in location A with IP 1) need to support VRRP to work as a primary link, the same with location B.

Note: To make sure your deployment goes well, you should contact Sierra for more detailed advice.