hard wired port on dpc... router dropping regularly

[FlashGordon7]

Hi,  I have a an xfinity dpc... router with 4 hard wired ethernet ports.   I run a long (~50 ft) ethernet hard wired run to a shed with a netgear splitter where it services a mac, 2 win 10 machines and a print server where i get ~600 meg download.   It has worked reliably for years, although this problem has been seen before by me.   Nothing that I know of has changed but recently if I don't work on any of these machines for 1/2 hour plus, the connection from the netgear splitter just stops working.   I can see it drops because the indicator light on the splitter for the run to the xfinity router just goes blank.  Sometimes I can get it back by power cycling the splitter or plugging and unplugging the xfinity ethernet line.   I thought ethernet activity would keep the line up but today I wrote a powershell script that pinged a server on my work vpn every 30 seconds and I could see that the line just dropped and the ping stopped working, even with a ping every 30 seconds.  wifi connections to my shed are very reliable but much slower.  Any thoughts, it's just wierd because it's so intermittent.   This happened about a year ago and it just went away.   I see something's that say that windows machines have an eco internet mode (it might sleep and that might mess it up) but I would argue the DPC.... is talking to the splitter, not the machine on the splitter. 

[FlashGordon7]

There is one other odd thing about this.   In my remote environment I completely power off everything every night, computers, splitters, print server.   It always works well in the morning (I'm typing this on it now) but by noon, if I stop using everything for 15+ minutes, it can drop off.

[EG]

Have you tried changing the port on the Xfinity device that the splitter plugs into ?

You could also try hard resetting the Xfinity device to factory defaults by pressing and holding in the recessed reset button on the rear for 30 seconds. This can sometimes clear up some weird behavior issues. You will lose any customized settings, and they will need to be re-configured from scratch. Good luck !

[FlashGordon7]

EG, Thanks.   Yes changing the port on the DPC... does fix it sometimes, but when this is happening by the next day the drop problem happens on the new port.    On router reboots I usually soft reboot with Comcast My Account.   Soft reboots do fix the problem, but in this case only temporarily.   That's a good idea to try a hard reset.   I know what you mean, sometimes routers and computers just get a bad entry and need a hard reset to clear them out.   It also would explain why once it starts, it doesn't go away.  I'll try that the next time I have a quiet house.  Thanks for the advice.

[EG]

Sometimes two different devices just don't play nice together for some reason. Especially when they are of different brands. Good luck with it !

[FlashGordon7]

yeah it was funny today. I left the mac and a personal win 10 machine on the splitter and put my work vpn machine on the wifi.  the splitter worked fine all day long with no outages.

[FlashGordon7]

Ok, I think I figured this out.  Not sure how much this will help others but here goes.  My situation is that I have a long ethernet run to a splitter (50+ feet) with 3 machines and a print server.   The long ethernet line run is obviously suspicious and there are testers you can buy that will test all 8 wires on your ethernet cables. I bought a tester and my wire run tested ok.   So this setup was failing.  I don't mind a simple failure where I just power cycle the splitter and off to the races.  This was harder.   The wifi and all the connections in the house would work fine when my splitter failed.   When the connection to the xfinity router failed I would sometimes have to reboot the xfinity router (tough or impossible with other people working in the house), sometimes move the ethernet cable between the 4 hard wired ethernet ports on the xfinity dpc... .  Sometimes it would take me an hour to get my remote splitter working again.  So I was watching my splitter and I could see that the run to xfinity router was out (not lit).   I was suspicious of my IOGear print server so I unplugged it from my splitter.  About 30 seconds after I unplugged the IOGear, the primary run from the splitter to the xfinity router lit green again and my splitter was fully functional with ~600 meg download.  For 3 days now I have not plugged in the IOGear to the splitter and everything (3 high capacity computers) worked perfectly.   I don't blame IOGear, this IOGear is more than 10 years old.  I think I notice that maybe the IOGear has a memory leak or something because it always starts working (I power cycle everything every day) and then fails after a few hours.  So if you are having this problem with a remote splitter hard wired to xfinity, experiment with different combinations of the devices (remove oldest devices first)  on your splitter and see if taking one off makes the problem go away.