Airport Extremes Were Killing My Network
I just managed to root-cause why my home network was acting up.
I had thought it was multicast flooding from my u-verse service, so I upgraded my switches to more professional units with IGMP snooping, which should prevent multicast from leaking out to multiple wireless access points.
That didn’t seem to make much difference. Then I noticed my ping time when I got my mac to connect to the Airport Extremes was running 500ms, compared to about 1ms on ethernet. Something is terribly wrong here.
I isolated it down to a single Airport Extreme, and then replaced it with a Dlink DAP-1522, which I had taken out in favor of the AXes a few months ago.
Voila, problems gone. It looks like a recent AX update caused this. I think it must have happened about the time I upgraded to Mountain Lion, which made the whole debug thing fun. Too many things changing at once.
One note on the D-link APs. If you don’t turn IGMP snooping off on them, they won’t pass multicast at all, so Airplay won’t work. Instead of asking the AP to do snooping, better to have the smarter switch do it, as it will pass local multicast addresses without IGMP.
I noticed a pattern in some of the ads I was seeing, and found the root cause of this pattern.
I don’t think I appreciate Verizon or their partners for engaging in this business. Hard to avoid some of them, though.
Here’s the whole list of partners copied from their “opt-out” page:
Centro Brand Exchange
DoubleClick by Google
Federated Media Publishing
Genome by Yahoo!
Google Display Network
Stack Exchange Inc
Yahoo! Ad Network
Finished installing my tenth Nest thermostat today. So far everything working as expected.
Had to use extra deep double-gang outlet boxes to have enough space for the Aube relays. Still need to make a pass through the house with a bucket of mud and do some patching of the holes I managed to create.
Setup is a little odd. Seems like the devices could detect that there are others in the house once they’re on the network and skip some of the set up on the thermostat.
I’m finding the iPhone app is feeding my (minor case of) OCD. Hoping that fades soon. Looking forward to seeing how my power bill does from here.
Installation tidied up with a double-gang box in the wall for the relay and the plate that came with the Nest device. Still needs a lick of paint…
Temporary installation showing the relay unit and the Nest device. I need to get a larger box to put the relay into the wall and this will look prettier.
Got my Nest thermostat working.
I bought two Nest thermostats within hours of their launch, partly because I have some very good friends working there, but mostly because I am the type of person who is unable to control his expenditures on new gadgets.
So I unboxed the first one, and after admiring the beautiful packaging, I pulled my old, ugly thermostat off the wall and discovered I have a problem.
Short story: I have electric baseboard heating, and the thermostats control the line voltage going to the heaters directly.
So, I needed a relay. It turns out the Canadians make one that fits almost perfectly. It’s from a company called Aube, the model number is RC840T-240.
The nice thing is this unit has a built-in transformer to supply the 24V needed by the Nest unit. No additional components are required, and the connections from the relay to the thermostat have matching labels.
My old thermostat controls both legs of the 220v supply from the heater, and the RC840T-240 only has a single relay, so I had to connect the red wire from the heater (the load) to the red wire from the supply. This is fine because I’m breaking the circuit on the black leg. It does mean anyone servicing the heater needs to disconnect the breaker and not just turn the thermostat down to avoid getting zapped, but that’s standard practice anyway; no one should rely on a switch on the wall when playing with electricity.
If I could have found a double relay with the same parameters, that would have been a bit better, but I’m comfortable that this is plenty safe, and my living room is smarter now than I am about controlling the temperature.
I have 8 more rooms with independent thermostats, so looking forward to the Nest units going on sale again, and hoping they have a bulk discount…
Added a photo of my temporary installation here.