UNIFI - APs suddenly jump to controller on different subnet

[CHR1S]

As per title, we have two controllers on two different subnets (Inf/Jr) that until today happily coexisted with no issues.

Today I have had 3 APs disconnect and appear in the JR console as "managed by other", they still have the IPs of the correct subnet however.

 

How can I wrestle them back?

 

Thanks

[m25man]

You have two controllers? Why?

 

By default APs will make a DHCP request and seek adoption on the local subnet.

The default url search is for http://Unifi:8080

 

If you have two controllers and your subnets are routable it would appear they have discovered each other.

 

The easiest way out of this is ssh to the affected APs and specify the inform URL manually. (You will find plenty of information on the UBNT site).

 

Best solution if your subnets are routed is setup a single server with V3.x software and run the multi site option.

 

We run a single controller on Azure with hundreds of APs across dozens of sites using L3 it makes it easy.

[CHR1S]

Thanks @m25man. Its a bit of a weird solution.

 

Two schools who originally had separate networks that are slowly being amalgamated (still two domains, DCs, etc etc). I think its a simple case of messed up VLAN tagging, however this is controlled at LEA level.

I must hold my hands up and say I'm a bit green when it comes to setting up a single controller solution that could encompass both and how it would still service the separate domains. Wouldn't one domains DHCP take priority over the other?

[m25man]

No it's not that hard actually,

All Unifi's automatically search L2 for a controller, so if one isn't found on the local subnet/VLAN it searches for an INFORM URL at http://UNIFI:8080/inform on L3

 

So all you actually need is a clear route for your Unifi APs to the cloud controller (taking into account proxies/firewalls/authentication etc) and the correct DNS Records on your local DNS

Eg UNIFI = cloudcontroller.myunifiserver.mydomain.com

CNAME/A Records etc

That way when a new AP picks up a local IP address it automatically seeks and hopefully finds your UNIFI controller and awaits its configuration download from there.

 

You can use ssh to manually set the inform URL on each UAP if you do not have the required DNS management.

 

In a school with restricted network access/filtering this may require some work at L2 to ensure you have your VLANs sorted so that the UNIFI management VLAN can see/route to its controller unhindered.

 

Provided all of your sites on the unifi controller have unique IP ranges the Unifi Controller will work out which subnet the request is coming from and assign it to the correct site group and and configuration.

If not they will be assigned to the default group pending a move by admin to the correct site.

 

Configured correctly, all you have to do is take Unifi to site, plug it in wait for it to resolve your Unifi controller URL and bingo it's working.

Login to the cloud controller management URL from your phone and view the traffic! Easy.

Edited February 5, 2015 by m25man