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ronya
Nov 8, 2010

I'm the normal one.

You hate ridden fucks will regret your words when you eventually grow up.

Peace.
I'm not a networking person, so newbie question.

I've got this topology:



(I've got reinforced concrete walls, APs are cheap, don't look at me like that)

At apparently random (maybe a couple times a week), the desktop (connected to AP#2 via cable) loses its connection to the Internet. Pinging the fibre router times out, pinging anything on the internet times out, but it can ping AP#1 and all other machines in the home network. It can also reach AP#2. From the command console in AP#2, AP#2 can ping the fibre router. Whilst this is ongoing, the devices connected to AP#2 via wifi are fine and can reach the fibre router and the internet. I've checked that they're not silently switching to one of the others - they are really only connected to AP#2.

This lasts for maybe ten minutes, then everything is fine again. If I reboot AP#2 it is fine as soon as it comes back up.

What the hell is going on, what kind of logging should I even try to gather to find out

ronya fucked around with this message at 06:45 on Jun 16, 2020

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ronya
Nov 8, 2010

I'm the normal one.

You hate ridden fucks will regret your words when you eventually grow up.

Peace.
Hmm, my fibre router is handling DHCP. The ISP software is hard locked to have a static range between .64 to .127 within the /24 subnet specified for the pool, I don't think it would re-use addresses... hmm

e: from the DHCP logs there's a device that is MAC randomizing (like so), maybe that's it. I'll cut the lease time down to an hour, maybe that will help

ronya fucked around with this message at 07:46 on Jun 16, 2020

ronya
Nov 8, 2010

I'm the normal one.

You hate ridden fucks will regret your words when you eventually grow up.

Peace.
No, not double connected

Mac randomization should be OK but I suspect whatever device it is requesting new leases really aggressively as well

ronya
Nov 8, 2010

I'm the normal one.

You hate ridden fucks will regret your words when you eventually grow up.

Peace.
There is indeed a smart TV (of the "localhost" variety). I could kick it off.

ronya fucked around with this message at 12:34 on Jun 16, 2020

ronya
Nov 8, 2010

I'm the normal one.

You hate ridden fucks will regret your words when you eventually grow up.

Peace.
Rebooting AP#2 resolves the problem as soon as AP#2 comes back online. That may be due to all the devices attached to AP#2 being connected to the network again so it may not be due to AP#2 itself though

I haven't tried physically disconnecting it, I'll try that the next time.

ronya
Nov 8, 2010

I'm the normal one.

You hate ridden fucks will regret your words when you eventually grow up.

Peace.

Garrand posted:

Kind of a tough one with the limited troubleshooting capabilities of ISP routers. If this device is eating up the DHCP pool it still shouldn't effect the desktop as long as it's connected since the router will just keep giving it the same address forever. Once the pool runs out it just rejects new device requests. This device may also be trying to set it's own IP addressing apart from DHCP for some reason. Do you have any smart tvs on the network at all? Those are notorious for just grabbing and keeping IP addresses forever, often holding onto multiple addresses at a time because they suck.

If it is actually an IP conflict, the best way to tell would be to ARP ping the IP address from another device when the desktop is acting up. I don't know what your other devices are but it doesn't look like there's a good way to do it in windows without downloading third party software. The reason I say ARP ping specifically is that all devices have to respond to ARP whereas a lot of devices will ignore regular pings (windows devices have ICMP responses disabled by default).

Without downloading third party software, you could do this, from another (windows) device:
arp -d //clears the arp table
ping [ip address of desktop] //see if anything responds
arp -a //shows the arp table, see if you see a mac address for the ip in question and if it actually matches the mac from the desktop

if one of those other devices does happen to be linux it may have arping in it (or it can easily be installed) where you just run it like a normal ping so
arping [ip address]
and that's it. See if some other unexpected device responds.

So it happened again... from the other machine, ping responds and the arp table mac addresses indeed matches the desktop

I physically unplugged the desktop afterwards and plugged it back in, and that also resolved the problem

Weird :\

I'm now wondering whether it's a software problem on the desktop itself, although I have no idea what could cause that either

ronya fucked around with this message at 19:53 on Jun 20, 2020

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ronya
Nov 8, 2010

I'm the normal one.

You hate ridden fucks will regret your words when you eventually grow up.

Peace.

ronya posted:

I'm not a networking person, so newbie question.

I've got this topology:



(I've got reinforced concrete walls, APs are cheap, don't look at me like that)

At apparently random (maybe a couple times a week), the desktop (connected to AP#2 via cable) loses its connection to the Internet. Pinging the fibre router times out, pinging anything on the internet times out, but it can ping AP#1 and all other machines in the home network. It can also reach AP#2. From the command console in AP#2, AP#2 can ping the fibre router. Whilst this is ongoing, the devices connected to AP#2 via wifi are fine and can reach the fibre router and the internet. I've checked that they're not silently switching to one of the others - they are really only connected to AP#2.

This lasts for maybe ten minutes, then everything is fine again. If I reboot AP#2 it is fine as soon as it comes back up.

What the hell is going on, what kind of logging should I even try to gather to find out

Update: it started happening to more computers on the network (able to ping AP #1, not able to ping the router). My current guess is the unmanaged switch (a Netgear GS308) crapping out.

I'll swap it out and see.

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