Intermittent packet loss? Need help

Networking
1

Hey all, I don't think I've posted here since the forums switched over to L1, but here I am.

For a couple months now, I've been having issues with my internet connection. I'll notice service interruptions, whether it be while playing games or watching videos, and my first action whenever this happens is always to open up a command prompt and run a ping test to the DNS server I use (googles public DNS).

What I've noticed is that I'm having intermittent packet loss issues. I called my ISP (spectrum) and they claim they don't see anything wrong on their end. I ended up replacing my modem with a newer one I had on hand(Arris surfboard sb161 to surfboard sb183) in the hopes that would fix it, but I'm still having the same issues.

The packet loss happens randomly, and it doesn't seem to be dependent on network load, it happens in the middle of the day when a lot of people are on the network as well as in the middle of the night when I'm the only person on.

It also varies wildly in how long it lasts, sometimes I'll have bouts of packet loss issues for half an hour or more, but most times it lasts less than 5 minutes, sometimes it even goes away within a minute of starting.

Everytime I notice it, I run ping 8.8.8.8 -n 100 in my command prompt, and sometimes I get solid "request timed out" messages, but other times I'll get a random mix of successful and timed out pings. Another thing I've noticed occasionally is a "Destination net unreachable" message, which makes me think it could have somthing to do with my TPLink n750 router. I have that router running as a switch, and it connects to my modem. I have a netgear nighthawk ac6900 acting in access point mode for my wifi.

Could it have something to do with my network configuration? I've had this configuration all year and haven't had problems until recently...

Thanks in advance for any help, and let me know if you need more info :slight_smile:

2

Not to sound like a dunce but have you tried testing the cable your signal is coming in on for issues?

3

Nah it's fine, tech support is all about ruling out the most simple things first. I haven't been able to test the coax cable coming to my modem, I don't have any way to test it. The best I could do was ask Spectrum if the signal my modem was receiving was in the right range, which they said it was.

The cable connects way up in our attic so to test the cable at all we'd have to get a tech out from spectrum to do so, and we actually had the attic rewired by them a little over a year ago, so I feel like it shouldn't be the issue.

Basically I'd like to rule out everything I can do myself before we have to pay a spectrum tech to come out and troubleshoot.

4

You should just be able to test it with a multi meter if I'm notr mistaken.

5

I only say that because that sound like a problem I was having back in 2006 with my internet connection same company tho at the time they were called time warner. Turned out to be bad/defective coaxial cable.

6

It could be a bad splitter, any minor power surge tried the shitty splitters that Charter uses.

7

Had an identical issue years ago when the position of the router & modem was changed in the house, and thus needed a coax re-wire. Turned out that the electrician had done a bad job of splicing the new coax extension and the old coax together.

Alternatively, your router is dying on you. You could use your AC6900 as a temporary router replacement to see if the TP-Link unit is at fault; or you could wire up a PfSense box to use as a temporary (or even just replacement) router.

Or (again), you the AC6900 is going bad. I have a nighthawk x4 around here somewhere, that completely ate shit within a year of use. The 5Ghz band straight out failed and can't be restored in software, and clicking on about half of the options in the Web-UI causes it to crash and burn. I have a particular hate for netgear routers to be honest. You can grab a powerlink kit and hardwire yourself via that to see if it fixes your issue.

8

You can use MTR or if in windows pathping to see where the interruptions occur along the route your packets take.


Just note that some routers/switches will drop ping requests by default (or if they are busy). If you see packet loss on the last node, look for similar numbers in earlier nodes to see where the drops are 'likely' occuring.

9

There's usually a diagnostics or status tab somewhere in the cable modem UI (try 192.168.100.1) that would show signal level in dB for each of the bonded channels, and more importantly pre and post error correction errors.

Post error correction error count should be really really low, 1 in a million maybe after a couple of hours or a day of running

If that post error correction count is low, packets aren't dropped by your ISP cable infrastructure or by your own coax, the problem is most likely in software somewhere/busy routers, bad ethernet cable, etc...