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I have Gigablast service that is now suddenly topping out at 300mbps DL and 5mbps UL. Up until last week I had full 1000mbps speed DL and 40mbps UL. My modem is a Motorola MB8600. Its obvious that COX has changed their system in some way within the last week or so and caused this issue.
I had a COX tech come out who determined that my modem is the issue and most likely needs a firmware update but that they wont update it since its customer provided!
I contacted Motorola who told me that they do have a firmware update to my MB8600 which they have forwarded to COX to provide to their customers. They said that ALL updates should be provided by COX. They said they specifically created this firmware after COX system updates have created intermittent connectivity issues and degraded speeds to many Motorola users modems.
Motorola said they will contact COX to tell them they should be pushing this update to me. We will see what happens....
Oh, and as a cherry on top, it looks like COX will be charging me $75 for the service visit since the problem was a "customer equipment issue".
I WISH COX SUPPORT WOULD GIVE ME AN UPDATE ON THE MB8600 MODEM ISSUES!
I've been intermittently taking speed tests and seeing if things have changed, as I'm sure you have as well. I also checked my router settings, and for some reason I had dynamic QoS on which may have been affecting my speed tests, because when I turned it off and then tested again this morning (unfortunately, before I had tested today, so I am unsure if it actually had an effect), I was up to between 400-500Mbps, and when I just tested now I got up to 535Mbps. So, either it's a gradual improvement, or perhaps some other fluctuation.
You can easily determine if there is a router or Cox issue with what I suggested. Eliminate your router from the equation.That's actually the main troubleshooting suggestion that Cox suggests so one can rule out that it's not a router issue. Until you do this test, I don't think you can really blame Cox. Afterwards, when you do the test and find out a direct connection to the modem doesn't help, then blame Cox ;'). Be interesting what you find out.
Well, as much as I hate to admit it, I did test up to ~950 Mbps when bypassing the router. Lovely. -_- Now to find out why the router is suddenly throttling the bandwidth.
seper8tor What router do you use? I have a Netgear Nighthawk.
Edit: As an addendum, turning off the Traffic Monitor function in the router settings has improved speeds by a couple hundred Mbps (!!!), but it's still ~700 instead of ~950 that I got with the one test w/o the router.
Edit2: After disabling IPv6 again, speeds are a smidgeon above 900 Mbps now. I do not understand why the darn router has a bandwidth loss with it enabled - quite annoying. But at any rate, thank you OpenBSD for your nudge to connect directly for the testing. As I had mentioned, I know that is always the best test, but I guess I just didn't realize the traffic monitor setting throttles it so much. (And it's also annoying that the router also has such a noticeable issue with IPv6 as well -_-)
how old is the router? does it have the latest firmware? have you tried resetting the router to default and set it back up again?
I just purchased it in November - it's an R7900P, and it does indeed have the latest firmware. I have not reset it back to default, though I am a bit apprehensive in doing so since I believe I had the same issue (with IPv6 'slowdown) with my older (previous) router, an Archer C9 that was running DD-WRT with a revision from maybe mid-2018?
Steelbender I do a lot of tinkering with router firmware and build my own custom firmware from open source ASUS firmware. I just know from experience that there are many different settings in consumer routers that can affect internet speeds. QOS and bandwidth monitoring are typical router settings that cause problems. Prevents the router from using hardware NAT acceleration (CTF). Your router in particular has a Broadcom CPU so make sure that CTF is enabled. This setting in particular will get you closer to 1GB speed. You won't be able to use QOS and bandwidth monitoring though and possibly other settings. At this point you should be at the Netgear forums.