[GRLUG] Ubiquiti issues

[Benjamin Flanders]

Short Story:
My AP's are having issues handing out IP's with DHCP. I am in no way a
networking wizard and could use help diagnosing.

Long Story:
I installed two ubiquity AP's in the office last month.  I started off
really liking it, it was cheap, the range was better than the old routers I
had, and the controller was nice to work with.

We have a small office with few wireless clients (around 10) and for a few
weeks everything was hunky dory.  Then people started coming back from
vacation and I started having issues.

It seemed that when I get above 9 clients the last clients won't get ip
addresses.  Sometimes I can get 13 with valid ip addresses.  Even clients
with valid leases don't get ip addresses if I reset the AP and that client
is one of the last to try getting an ip.  It isn't consistent, in that
sometimes a client connects but then loses it and sometimes a client don't
connect but then half hour later it will connect.

I've been working with Ubiquiti (they don't seem all that knowledgeable)
and last week they remoted in and we tried a bunch of different settings
and even pulling the AP from one side of the office to right next to the
other and we couldn't get above 13 clients.

One weird thing that happened during testing is that we had a device that
had an ip address then lost it (according to the controller), but the
device still had a valid ip address when I looked at the ip settings, so it
didn't know it had lost the ip address.  With this device I was able to
ping our erp server and other ip addresses but I wasn't able to ping the
DHCP server, then about 5 minutes later it couldn't ping anything.

They said it looks like an issue with the DHCP server and suggested
increasing the address space.  My IP lease range isn't full, but I could
still increase the pool by about 70 addresses, which I did.  Right now when
I look at the controller I have 17 clients and only 1 doesn't have a valid
ip address, but about half hour ago I had 18 clients and 3 not getting an
ip address. So it got better, but still not right.

According to the Ubiquiti forums it seems that others have this issue and
there isn't a fix in the forums.

Some more info:
My lease pool is 192.168.0.12-200 I have 97 open ip address I could hand
out.
My DHCP server is windows 2008 rc2
The Windows 2008 rc2 is a client on VMware
The Ubiquiti controller is installed on the same windows server.
The network consists of cisco switches.
Wired devices have no issue getting ip addresses

So my questions:
Does DHCP need a certain % of open addresses in the pool?
Could it perhaps be an issue of having the Ubiquiti Controller on the same
server as the DHCP server?  - I could start up a linux server on VMWare and
put the controller on that.  I'm doing this right now(I just thought of
this)
I understand that this is the Linux Group and this could possibly be a
windows DHCP issue so is there a local windows group I could go to if you
all think windows is the issue.
Could the Cisco switches be filtering or interfering somehow?

Share and Enjoy
Ben
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