Mix and match - cable company WiFi and UniFi APs

[timeshifter]

About two years ago I installed 4 UniFi APs in a very large, old, 3 story house. It's been trouble free.

Two days ago I installed a new wireless printer and I installed a UPS. The printer is probably not even related. The UPS I installed to power their cable company modem / router combo and all the power injectors for the 4 APs. This required unplugging everything and plugging it all back. Shouldn't be a big deal. I did't go around and check or inspect each AP. But it was working after unplugging and plugging things in behind the UPS. I used my laptop on their WiFi for about 5 minutes afterward.

I noticed during all this that their modem / router combo (supplied by the cable company) had it's 2.4 and 5 GHz lights on. I was going to go in and disable that default setting as I was expecting to see the standard SSID and password as supplied by the factory. I was surprised to find that it had been programmed to match the UniFi system. I NEVER SET THAT UP. I always disable cable company WiFi when I do such an install. But in that moment I didn't recall doing that and thought the guy I worked with on the wiring did that (he often does), so I didn't want to undo things that had been working.

About an hour after I left I got a call. They couldn't get on their WiFi. All of their iPhones were saying "Incorrect Password". Their MacBook laptop couldn't connect either.

I walked them through a reset. Had them unplug the modem power and all 4 injectors. Then I had them power on the modem and wait until it was all the way up, and they connected to it's WiFi. Then they powered up the rest of the APs. Then they could connect and within a few minutes everything was working, including a few WiFi security cameras.

A day later I get a text that they can't get on their network. That's where I'm at now. I looked at my invoice and I had noted that I had disabled the cable company's WiFi. Also, I'm pretty sure the modem came after my install as the cable company had a big city-wide upgrade and everyone got new modems.

For reasons I can't articulate, I ALWAYS like to disable the WiFi from other manufacturers and use the same SSID on like hardware from one company - like a typical UniFi installation.

QUESTION: Is mixing and matching like that generally a bad idea? Or do you think it's no big deal?

 

[YeOldeStonecat]

I ALWAYS like to disable the WiFi from other manufacturers and use the same SSID on like hardware from one company - like a typical UniFi installation.

I also do. You want to avoid mix matching hardware. You want a multiple AP network to be of the same brand/version firmware/SSID/security type. If you start mix matching, it's an "anything goes" game. Sometimes with some mix matched hardware...it might work kinda/sorta OK, or people don't notice the hiccups. In other cases..they might fight each other. Perhaps the ISPs CPE doesn't do WPA2/AES in the same exact manner of the better biz grade APs. Or perhaps it only does the WPA2 mix matched mode. Who knows, why guess, why waste time scratching your head.
Disable, and use the superior product that you can support/manage. Centrally managed systems like Unifi, or OpenMesh, or Aruba or Ruckus...they're designed to work "together"...meaning all the APs work with each other, nice and even across the board.

 

[timeshifter]

Thanks for helping me understand that better. I know it's a bad idea from way back, but a bit fuzzy on the details.

Do the UniFi APs "talk" to each other in some way in a small install like this one where it's just 4 APs and no controller?

 

[Your PCMD]

I always disable cable company WiFi when I do such an install. But in that moment I didn't recall doing that

A day later...... I looked at my invoice and I had noted that I had disabled the cable company's WiFi

That's contradiction. Anyway, I assume you've already been paid for the job. If that is the case, you owe it to your client to make a return visit to resolve the issue with no charge. Take "no charge" as you like. I have had to do that a couple times. But my terms stipulate no charge in a certain way as such:

At Your PCMD, we value our customers and are about ensuring that we delivery a professional service to our clients at affordable prices. We have a 30 day warranty policy on hardware only. Services have a 2 day warranty. If within 2 days after our technician has completed their visit you experience the same technical issues as those that you first reported to us, or that the work carried out by our technician prevents you from using your computer, contact us for a return visit and we'll provide the 1st hour for FREE. If diagnostic and fixes take longer, normal billing rates apply after 1 hour.

 

[YeOldeStonecat]

Do the UniFi APs "talk" to each other in some way in a small install like this one where it's just 4 APs and no controller?

The controller can help manage multiple APs...yes. They don't necessarily talk to each other. But if the site has been setup optimally in the Unifi controller...yes it kind of does what you're thinking to a degree...such as if you have load balancing turned on. The controller will determine if a preset threshhold on 1x AP has been reached, and it will nudge clients over to neighboring APs.

Roaming is a function of the clients these days, not the APs.

 

[timeshifter]

That's contradiction.

I installed the system in August 2015. I didn't go back until February 2017, but that was for other things like upgrading their computer. WiFi was just working, never came up. Was back the other day to install a new printer and a UPS on the network equipment.

While I was installing the UPS I noticed the modem had the WiFi lights on, and that it was programmed for their SSID that matched the UniFi system. That surprised me as I don't normally do that. But it had been over two years since it was setup. I wasn't 100% sure I didn't do it. Thought maybe my home theater guy may have done it. Didn't matter as at that moment they had been problem free for over two years. Had no idea a reboot of everything would cause issues, especially considering that their power had been out a few days ago which would have caused it all to reboot.

It wasn't until I pulled up the invoice that I saw my detail stating that I disabled the cable company WiFi. Someone after had to have turned it on and programmed it to match.

 

[timeshifter]

Turns out that the APs didn't have uplink. Their LEDs would flash every 30 seconds or so. Their router was not handing out IP addresses. Rebooted router and it all came back up and worked fine.

I did establish that a cable tech installed their new modem and set up matching SSIDs on their modem. When I arrived today the only WiFi network sources were coming from that modem. I tried to connect and got the incorrect password error. So I disabled the modem based WiFi and just ran it pure UniFi.

A couple of additional thoughts / questions - 1) does UniFi turn off radios after a while and 2) what caused the modem to lock up.

1) Do the APs shut off their radios when there is no uplink? That appeared to be the case today. They were powered on, LED would occasionally flash, but I didn't get a signal from them.

2) What may have caused the modem to lock up / stop handing out DHCP? The have four FLiR WiFi security cameras. They hadn't had this issue before as far as I know. My theory is that the cameras connected to the modem WiFi instead of the APs and it stressed the little guy out with pushing so much data through it's pathetic little radios. Whereas in normal operation that data flows through the UniFi equipment. Is that a good theory?

 

[Markverhyden]

I'm never heard of an AP "going to sleep" so to speak. So my guess is it was just a coincidence. Personally, in a situation like your's I'd have power cycled everything once more before leaving, then test again just to make sure all is well.

 

[YeOldeStonecat]

A couple of additional thoughts / questions - 1) does UniFi turn off radios after a while and 2) what caused the modem to lock up.

1) Do the APs shut off their radios when there is no uplink? That appeared to be the case today. They were powered on, LED would occasionally flash, but I didn't get a signal from them.

2) What may have caused the modem to lock up / stop handing out DHCP? The have four FLiR WiFi security cameras. They hadn't had this issue before as far as I know. My theory is that the cameras connected to the modem WiFi instead of the APs and it stressed the little guy out with pushing so much data through it's pathetic little radios. Whereas in normal operation that data flows through the UniFi equipment. Is that a good theory?

Nope Unifi does not turn off radios..even if they have no ethernet uplink. They just turn into a dead end. Technically it's called "isolated mode"..they're beacon looking for other Unifi APs that are wired..so they can do a wireless uplink (if you tell them to do that). But otherwise...no ethernet uplink, they will still broadcast, but nobody will be able to connect because no DHCP can flow through them.

What causes an ISP CPE to lock up? heh...usually they're a piece of..junk.