LAN failures

[f00dl3]

I posted a thread on this topic earlier and it went away, but now it's back.

Every few days - about once per week, my router drops the entire LAN portion of the network. I had this problem on multiple routers - Netgear WNR2000v3, Netgear AC2700 series, and now the Asus AC3200. I had this on Road Runner/Spectrum with a SB6121 modem, and with Google Fiber 1000 w/ their fiber box.

With the Asus AC3200 I do have a handy work-around - with SSH enabled I can do a reboot on the router to fix the problem, but SSH connections to anything past the router do not work, the PC can not connect to the router, and all network devices are inaccessible from the PC - such as IP cameras.

The problem really got going when I went from using 4 GB/day to 20-25 GB/day with weather data fetches (GRIB2 files, XML feeds.)

The Asus logs do not show any events. The problem is not purely data related because it can happen even at a period when sustained use is at the background 200-300 Kbps / just IP cameras active. It can happen under load as well though. My peak data use maxes around 45-70 Mbit/sec, twice a day in a 30 min window when I'm pulling "00z" and "12z" GRIB2 model data.

I'm going to try to replace 3 Ethernet cables today to see if that helps.

 

[System Error Message]

when it happens are the networking devices not responding?

 

[abailey]

I think you are on the right track with replacing cables. I would definitely start with things that have remained the same with your switching of routers and ISP's (like cables, maybe switches, etc.).

 

[TonyH]

I'd try another AC adapter on a whim.

I think you are on the right track with replacing cables. I would definitely start with things that have remained the same with your switching of routers and ISP's (like cables, maybe switches, etc.).

For the time being use only one port using known good cable. Start from the step.

 

[degrub]

I'd try another AC adapter on a whim.


For the time being use only one port using known good cable. Start from the step.

Put a UPS with AVR in front on the power.

 

[TonyH]

Put a UPS with AVR in front on the power.

That can give stable AC power to the adapter which is little switching type unit. If adapter's switching circuit acts up UPS, AVR are no help.

 

[KenZ71]

Start with basics... when I movedo all my network gear to a central spot it worked great when I was next to it. Then when I left & went upstairs nothing.

After several trips up & down stairs guess what the issue was? Modem & switch were on a plug turned off by light switch when I left room.

So check that, wall warts / power plug for Modem & router, etc.

 

[f00dl3]

All the "always-on" equipment - PC, router, Fiber box, and Google box - are on UPS battery backup. Old router / cable modem was too. (Fiber box has a slighty higher load draw than the Cable modem did but well within capacity / less than 20% load on the UPS even with PC + Router + Fiber Box + Google Box.) Using a APC UPS XS1500 series. UPS shows no power interruptions for quite some time. UPS is actually monitored via shell scripts and apcupsd from the Ubuntu box.

The problem continues after building out new Ethernet cables. Had to SSH reboot it again from my phone Saturday to get the LAN segment back up. Now starting to wonder if my motherboard has a jabbering NIC? With the amount of traffic I'm passing running a tcpdump is going to be a pain... 25 GB/day for at least 5 days before it fails it will probably be difficult to filter out the offending packets causing the problem in a 125GB+ packet dump...

 

[f00dl3]

SO it turns out it was not a router level issue at all. I did some in depth testing via SSH as it just happened literally 5 minutes ago... I was able to ping other LAN devices. I was not able to ping the desktop. Restarting the Networking service on ubuntu did not fix the problem, but disconnecting/reconnecting under Settings fixed it.

It's a software level issue. Mystery solved.

Hey - I got a cool router I love out of it all!