Router limits internet speed

I've got:
- an internet subscription for 500 Mb/s;
- the Netgear Nighthawk R7000;
- and an annoying problem.

When im cable-connected i achieve almost 500 Mb/s, so that's more than great.

But, roughly once a day my router is limiting that speed to +/- 90 Mb/s. All connected devices experience this problem, so its certainly a router-side problem.

The current solution is simple: Unplug the LAN-cable from the router and plug it back in. Not more, not less. Even a reboot is not necessary.

But offcourse i don't want to do this every single day. It's getting really annoying.

So my question is: Why does this happen and how can i solve it?

Ramon Bakker

Posted 2016-11-07T17:47:08.780

Reputation: 103

What cable are you using to connect your router to your Internet service? Did you make it or was it professionally made? How long is it? What category is it? Which Ethernet wiring standard does it follow? – David Schwartz – 2016-11-07T18:56:49.797

The router is connected to another router (same brand and type), which is constant at 450~500 Mb/s. I did make the cable between those 2 routers myself. Its about 30~40 meters long and of type Cat 5e. But, that cable delivers always 450~500 Mb/s when connected directly to my computer. – Ramon Bakker – 2016-11-07T19:37:16.617

Aha! Which Ethernet wiring standard did you follow when you made the cable? I'll bet you got the mapping of pins to pairs wrong. That would perfectly explain everything. – David Schwartz – 2016-11-07T19:39:13.990

Ill used the straight method – Ramon Bakker – 2016-11-07T19:43:15.563

Right, but which wiring standard? 568A? 568B? If the answer is "neither" or "what's a wiring standard", there's your problem! See my answer. – David Schwartz – 2016-11-07T19:43:48.717

what's a wiring standard – Ramon Bakker – 2016-11-07T19:45:56.430

See my answer. You got the mapping of pins to pairs wrong. It's a very common problem and it causes exactly the symptoms you're experiencing. If you get the mapping right, noise and crosstalk almost completely cancels out. If you get it wrong, it's massively amplified. – David Schwartz – 2016-11-07T19:47:30.673

568B according to your link – Ramon Bakker – 2016-11-07T19:48:31.300

Double check and make absolutely sure that the wires are as documented in the link. Having them wrong would perfectly explain your symptoms. Note carefully where the green and blue wires are. – David Schwartz – 2016-11-07T19:49:09.397

I've got a wallconnector between and i think i connected thta one wrong, but im not sure – Ramon Bakker – 2016-11-07T19:59:26.183

Like this one: http://www.cablestogo.com/product-images/27414/600/27414a.jpg

– Ramon Bakker – 2016-11-07T20:02:13.313

I'm pretty close to certain you've got the pins-to-pairs mapping wrong somewhere. That or you just have a poor quality connection somewhere. – David Schwartz – 2016-11-07T20:03:23.977

How do i correctly connect this one: http://imgur.com/a/UJrd6

– Ramon Bakker – 2016-11-07T20:06:26.117

Let us continue this discussion in chat.

– David Schwartz – 2016-11-07T20:08:28.093

Answers

When you made the Ethernet cable, you got the mappings of pins to pairs wrong. You have to follow an Ethernet wiring standard. Otherwise, the cable will fail intermittently and unpredictably at gigabit speeds.

See how to make an Ethernet cable for more details.

David Schwartz

Posted 2016-11-07T17:47:08.780

Reputation: 58 310

Changed the mappings as described in your link. Waiting the next few days for the result. Keep you posted. – Ramon Bakker – 2016-11-07T21:10:36.477

1So far so good, so i'm gonna say it worked! – Ramon Bakker – 2016-11-09T16:52:22.600

1Still good, so this was the solution! – Ramon Bakker – 2016-11-11T20:15:02.473

1Days later, still didnt had any speed drop-down or lost connection. So definitely this was the solution. Many many thanks to you :D – Ramon Bakker – 2017-02-08T22:42:51.930

90Mb/s sounds suspiciously like it's running at 100M mode instead of Gigabit Ethernet mode. Does the netgear UI allow you to see the current connection speed of the LAN ports?

Try to find the exact bottleneck source. WHen it happens, you can try a transfer between 2 of your computers (Iperf) which should operate well above 200mb/s. You can also try to "lock" the network card to 1000 instead of using auto-negociation mode, (which might cause your computer to lose connection completelty instead of dropping to a slower speed)

It's also possible its the connection from your router to your modem that's stuck at 100. This is the purpose of a LAN-LAN test.

As far as what to do once you've confirmed it's an auto-negociation LAN issue it might be solved with a firmware upgrade/downgrade or new ethernet cables...

1000mbit/s uses all 8 conductors in the wire and 100 uses only 4, but as soon as theres a bad contact somewhere it switches to 4. Either there's a bad contact, or the router 'thinks' theres a bad contact and switches erronously (firmware upgrade needed)

cloneman

Posted 2016-11-07T17:47:08.780

Reputation: 1 016

1"You can also try to "lock" the network card to 1000 instead of using auto-negociation [sic] mode..." The IEEE 802.3ab standard for 1000BASE-T (1 Gbps ethernet on UTP) requires auto-negotiation, so it should not be possible to set it to only use 1 Gbps. When troubleshooting, you should always start at layer-1. – Ron Maupin – 2016-11-07T18:48:39.727