Widely variable speed tests on wired connection R6700v3
Just replaced my old 6700v3 with a brand new one. After going through the setup via the nighthawk app it forcefed the router a firmware update. Version on the router portal says V1.0.4.120_10.0.91 and no other updates are avilable. The connection is hardwired Cat5e Ethernet. 15yrs ago I wired my home with Cat5e and ports in my living room where the cable connection is and my bedroom. The only wiring not inside the wall are the connections from modem to wall and the wall back to my router. Both are Cat5e cables too; one from this new router and the other from the one I just replaced which is an identical unit. This is longish length, but well under 100m limit of the cabling.
I pay Comcast for 900Mbps down / 20Mpbs up. When I plug the cable from my wall carrying just the cable modem connection I get 980Mbps download speed; 23Mbps up. So for both up and down the speeds are greater than the stated connection speed straight modem to PC. So the wiring is good and the connection is stable.
When I plug into this router though thing go south. On the advanced tab>QoS Setup there is a speedtest option. This shows "uplink internet bandwidth detected is 3.1Mbps" after a test. That cannot be right since it's significantly lower than it should be. I check speed through comcast's portal. The URL speedtest.xfinity.com (xfinity speedtest portal I guess?) and it barely breaks 300Mbps down and 23Mbps (?!). Sometimes that downspeed is lower or higher. So what is the router web portal reading for upload speed? It's obviously not reporting speed right.
Going to speedtest.net and it barely breaks 850Mbps down and 23 up. So I presume this last test is the correct one since it most closely resembles the connection speed I'm expecting.
But my question is why the wide variance in these tests and why the heck is the router reading 3.1Mbps down when it's 23Mbps up on the other two tests? And why am I losing almost 50Mbps of download speed (bandwidth?) through the router? And that loss is variable. I've had speeds low as 600Mbps through speedtest and high as 850Mbps through comcast's portal too.
I see other posts note that turning off QoS and Traffic management are releated to speed caps in this router. No changes to speed plus or minus with QoS on OR off. Same with Traffic management. No effect. Both show same 3.1Mbps uplink speed which by now I consider to be bogus reporting and I'm still losing bandwidth through the router.
Is this just normal to have these tests bounce around? If I were on WiFi I might expect it but over wired Ethernet? And normal to lose a bunch of bandwidth through the router? And to answer an obvious question "What else is using your internet?" The answer is nothing significant; I have two echo dots, an ecobee thermostat and my android phone. That's it. During the speed tests those should make no difference.
Re: Widely variable speed tests on wired connection R6700v3
A couple things.
1. don't trust the built in speedtest. It isn't accurate at speeds over 300-500mbps because it rarely picks an appropriate server
2. Speeds will vary over that 800mbps even on some test sites. I've had some that reliably max out gigabit an others that strugged.
3. The R6700 needs ctf (cut through forwarding) to hit gigabit speeds. cut through forwarding forwarded all traffic without packet inspection. Certain services disable cut through forwarding and that puts packet inspection on the cpu. Which wasn't fast enough to max out gigabit. these include qos, access control, traffic monitoring, and parental controls. Sometimes you can just disable all those services and reboot and it works. Othertimes I've seen CTF not get re-enabled after disabling those services. In those cases, a factory reset is needed. What I usually tell people is try the factory reset and test its speeds with everything in a default configuration. If it maxes out speeds, then start making your changes and test it.
4. If after a factory reset, you're still not hitting full speeds, try installing version 1.0.4.106 of the firmware. Do a factory reset and reinstall. disable auto updates. Then test it.
