RT-N66U WAN Speed Slow

[gclimer]

I'm using the RT-N66U (fw: 3.0.0.4.374.35_4 (Merlin build)) on a 1 gbit WAN connection.

When the router first boots up, I can do a speed test and I get >900mbit/sec. After an arbitrary amount of time, it drops significantly - sometimes dropping as low as 9mbit/sec. Once I reboot the router, all is well again.

I ran an test using iperf to make sure it wasn't the LAN ports flaking out on me - I'm getting >900mbit/sec for LAN traffic even when the WAN speed is slow.

This happens on every firmware that I've tested. I even tried out Tomato (shibby), but it won't even support the full 1gbit WAN speed at all. I think the max throughput I got with Tomato was in the 200mbit range.

I realize that 1 gbit connections are rare - but has anybody else experienced their WAN speed dropping like this?

EDIT:

Poking around in the web interface, the WAN port link state is now "10 Full Duplex" - so it seems like the auto-detect is freaking out and dropping from "1000 Full Duplex" down to either 10 or 100 at times.

 

[L&LD]

Switch to a good/known CAT 5e or CAT 6 cable between the WAN and modem to rule out the cable as the problem.

You may also want to try the most current RMerlin version 374.36Beta 1 SDK5 for the N66U.

https://www.mediafire.com/folder/bkfq2a6aebq68//Asuswrt-Merlin#y9ctdb7ujzyzk


Direct link
http://www.mediafire.com/download/gfizwhyhr87cgi9/RT-N66U_3.0.0.4_374.36_beta1.zip

 

[gclimer]

Any reason why the auto-sense would change from 1000mbit to 10mbit suddenly though?

 

[L&LD]

That's why you have to test a with a new cable. If the cable is fine; then the modem or the WAN port on the router may be faulty (I would get the ISP's modem replaced first).

 

[gclimer]

My ISP doesn't have a modem - the fiber comes in directly to a main box on the side of the house, and then a cat5e cable runs from the box to the inside of the house. (Not to say the box outside isn't faulty, just unlikely, considering it was replaced only a few months ago when they upgraded my connection to 1gbit.)

The problem is that the issue happens so sporadically - there's no rhyme or reason, and I can't cause it to switch on-demand. So it's possible that a new cable will work for several hours (and in fact, unplugging the current cable and plugging it back in has been working for a couple of hours now).

If another cable does the same thing, I'll loan it to a friend who also has the same ISP and same speed to see if it's occurring at his house - that would help rule out the ISPs equipment.

 

[L&LD]

It wouldn't rule out the ISP's equipment for me (they are responsible to replace it, correct? On their dime?).

Have the cable checked (seems it is not easily replaceable) and maybe re-terminated.

If the WAN connection speed indicates that it still fluctuates, then try a switch or another router to test your current routers WAN port. Then you'll know for sure if it's the ONT connection or your router's WAN port (or; maybe re-terminating the CAT5e cable fixes everything for you).

 

[gclimer]

Sorry, what I meant was that I would loan my router to my friend to test at his house - if the router acts the same on his connection, that's a pretty good indication it's the router, considering his pfsense router doesn't seem to have this issue.

I already ran a new cable from the ONT to inside the house once - and that was because the cable coming in was DEFINITELY bad and only did 100 mbit. After I replaced it, I connected my laptop directly to the connection (bypassing the router) and the speed test registered between 900 and 1000 mbit.

I'm going to play around with different cables later when I notice the speed drop again. No sense in doing it now while they're holding steady.

 

[Symbiot]

Hi

any news on this..
I am experiencing something similar..

I have 1Gbit, and asus ac66u, and speeds maxing at 150/200..
removing the asus and testing directly gives me much higher speeds..
I don't see an initial high speed.. just the low speed..

will have to check the wan port link state..