I have a network across two buildings that are quite close to each other. Each building currently has it's own network, and there is a wireless bridge between the two. Each building has it's own internet connection which is plugged into a router. The router has failover set to use the other building's connection if it's internet goes down, as well as to route traffic to servers in the other building when necessary. Each building also has several APs broadcasting the same SSID.

I have drawn up a simplified network diagram for clarity: network diagram

Currently, clients connected to the Wi-Fi at building A need to disconnect and reconnect when they go to building B, as the DHCP lease from building A is no longer valid. Is it possible to have clients roam between sites without doing this?

The routers on each site are Ubiquiti EdgeRouters, and the APs are Unifi AP-Pros. The SSID cannot be changed for various reasons, however there would be no issue on having the clients using NAT to get to the main network at each building (I believe this is how the Cisco Meraki APs deal with this issue)

  • 2
    The best way to do this is to use a controller-based wireless network. If you don't change IP addresses, then you have to tunnel the data back to the home AP. Controllers make this much simpler.
    – Ron Trunk
    May 24, 2016 at 11:51

2 Answers 2


What Ron said. A wireless controller with lightweight access points. The access points would provide the wireless connection where ever they are located, but the connection actually comes out at the wireless controller. So you could roam from access point to access point and keep the same address, since the controller is connected to a network. This is a from a guy that managed Cisco wireless networks with over 600 APs.

i just dont see how the APs could pass a connection from one to another without knowing about each other and/or being connected to the same wireless controller.

maybe this link will help you: https://help.ubnt.com/hc/en-us/articles/205144590-UniFi-What-is-Zero-Handoff-

  • I've been going through this with my colleagues, we came up with the idea of having a central Wi-Fi DHCP server set not to broadcast, and a DHCP relay on the Wi-Fi interface of each router. The router would then NAT the traffic, allowing each client to have it's own IP and roam without it needing to change.
    – Foxocube
    May 25, 2016 at 15:49

Depending on how far apart the two buildings are, you could also potentially shorten the DHCP lease time to where it is impossible to get from one building to another without having your lease expire. This would force the clients to ask for a new IP when they get to the other building.

  • The buildings are about 30m apart. Far enough to merit separate equipment, but there's enough overlap to roam directly from one network to the other
    – Foxocube
    May 25, 2016 at 13:23

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