RT-N66U not able to get full speeds

[Reed Beatse]

For almost a year, I have had 100/10 speed from Comcast in my area. About a week ago, I got a mailer that Comcast had increased their speeds to 150/20 and I just had to power cylce my modem and router and PC and I would be fine. I did those steps and now, if I connect directly to the modem I get the new, higher, speeds but to the router I still only get the old speed.

I do have port forwarding enabled for my Plex application but that is it and I do not think that should be an issue but someone can tell me differently. I have read previous posts that I should do a factory reset, although I do have the latest Asus firmware installed (installed/updated 2 days ago as my first troubleshooting attempt).

I am willing to put other FW on, like Merlin's if that will help, or if there are settings I should try first. I am not a network guy and so I am sure everything else on the router is stock software settings. I would really like to get the upgraded speeds that they are giving me and I would assume that with the RT-N66U and a gigabit card in the PC I should be able to.

Thanks for any assistance!!

 

[L&LD]

'Latest Asus firmware' means little. What version is it?

'But to the router I still get only the old speed' is also ambiguous. Is this wired or wireless? What clients and how far from the router (and how many obstacles in-between)?

I would always suggest to install the latest (378.56_2) RMerlin firmware or the john9527 or hggomes forks, rather than stock Asus firmware.

Did you do a reset to factory defaults after you flashed the firmware? Did you minimally and manually configure the router to secure it and connect it to your ISP? Did you use new ssid's for your wireless bands? Did you test the channels (1, 6 and 11 for the 2.4GHz band and all channels for the 5GHz band) after doing the above for the highest throughput and lowest latency?

Do you have any features turned on that would tax the cpu and lower your routing speeds?

 

[Reed Beatse]

Latest Asus firmware' means little. What version is it?
3.0.0.4.376_3861

'But to the router I still get only the old speed' is also ambiguous. Is this wired or wireless?
Wired. BTW, the old speed is the same one (100/10) I had before the speed was increased by my ISP to 150/20.

What clients and how far from the router (and how many obstacles in-between)?
It's about 3 feet from the router, wired with a 5 foot cat-5e cable. The modem is about 4 inches from the router wired with a 1 foot cat-5e cable.

I would always suggest to install the latest (378.56_2) RMerlin firmware or the john9527 or hggomes forks, rather than stock Asus firmware.
That is what I was asking if I should do and if it would make a difference; as well as if there are particular settings within those firmware's that I should set.

Did you do a reset to factory defaults after you flashed the firmware?
No, I did not realize that after upgrading the firmware, I needed to reset and reconfigure the router.

Did you minimally and manually configure the router to secure it and connect it to your ISP?
Yes, it is secured and configured and has been as long as I have had it. Nothing has changed except that the modem is not getting higher speeds and the router is not.

Did you use new ssid's for your wireless bands?
If by new, you mean different than the ones I had before I upgraded the firmware, then "No". If you meant different than the default, then "Yes"

Did you test the channels (1, 6 and 11 for the 2.4GHz band and all channels for the 5GHz band) after doing the above for the highest throughput and lowest latency?
No, I wasn't testing any of the wireless for throughput at this point, just direct wired. Once I have the wired working correctly, I will look at these if I have problems with wireless also.

Do you have any features turned on that would tax the cpu and lower your routing speeds?
None that I know of. As I mentioned, I have just basic configurations set.

 

[mstombs]

Latest Asus firmware' means little. What version is it?
3.0.0.4.376_3861

Good call by L&LD then, quite a few updates since February 2015

http://www.asus.com/Networking/RTN66U/HelpDesk_Download/

BUT I doubt they will make much difference, the N66U with lots of features enabled has a real WAN performance limit of not much more than 100Mbps, I could get close to 150Mbps with Tomato, but switched to asuswrt-merlin for higher. This is a CPU limit, there is a reason why Asus now make many more higher power devices! If you enable fewer features i.e. not per-IP accounting you can enable Broadcom fast nat CTF, then the N66U can achieve over 200Mbps in WAN performance. Helpful config options and status messages about CTF in Asuswrt-merlin mod, not sure about others.

See also other threads with basically the same problem in this forum, different WAN types clearly need different CPU resources so experience with different ISPs variable - but all symptomatic of being close to the limit.

 

[Nullity]

I get ~200Mbit wireless & 260Mbit wired throughput on my RT-N66U with CTF (forced) disabled.

With CTF people have reported over 900Mbit through the WAN. There are a few Speedtest.net results if you look for them.

 

[mstombs]

The trustworthy router ranker on this site quotes 731.6Mbps throughput for the N66U under careful lab conditions so I don't believe 900! It is very difficult to those speeds on Gigabit LANs let alone WAN. But it is quite likely a function of how an ISP implements your rate limit, latency and tcp/ip window tuning etc. The quoted speed may be a cap and with time domain multiplexing to get the average over say 1s you have to have bursts of much higher for shorter periods. I posted some speedtest results here:-

http://www.linksysinfo.org/index.php?threads/max-throughput-of-asus-rt-n66u.71080/

Cable internet WAN type dhcp, I believe pppoe wan connections have extra overhead.

 

[Reed Beatse]

Good call by L&LD then, quite a few updates since February 2015

http://www.asus.com/Networking/RTN66U/HelpDesk_Download/

Thanks for the info. I had checked for firmware update through the router and it had updated it to what it said was the latest. This was 3 days ago, not in February.

I will try the reset, this download and then Merlin's latest. thanks again.

 

[dlandiss]

What clients and how far from the router (and how many obstacles in-between)?
It's about 3 feet from the router, wired with a 5 foot cat-5e cable. The modem is about 4 inches from the router wired with a 1 foot cat-5e cable.

Just as a troubleshooting step, replace that 1' cable with 3' or longer. Some technicians have reported problems with ultra-short Ethernet cables.

 

[Reed Beatse]

OK, I have reset the modem to factory settings, installed the latest Merlin firmware (378.56_2) and I am still getting 98 down and 9 up when if I connect directly to the modem I get 148 down and 19 up (which is what Comcast has told me I should now be getting). QoS is not turned on. When I run the speed test the CPU and memory are never past mid point

Is there anything else I can look at? This is a wired connection (and to @dlandiss 's point, I have replaced the cable with one that is 3').

Thanks for any help!!!!

 

[dlandiss]

Reed, my Charter Cable connection is rated 100/4 and using my RT-N66U as the main router I get both wired and wireless speeds of 135/4.3 even on my Android mobile. I use John's fork, mostly because I also have a big house and need the range.

I'd be glad to share my settings with you if you think it would help, although they won't mean much since my wired LAN settings are pretty much the defaults except for some manually-assigned IP addresses. No IPv6, no VPN, no overclocking. Firewall on, DoS protection off.

 

[Reed Beatse]

Well, now I am at least getting somewhere. I just downloaded the Speedtest app for my iPad and ran it and, lo and behold, on my wireless I am getting 178/12! I hadn't checked it before because I assumed if my wired connection wouldn't get it the wireless would be worse. So now I am going to try switching ports to see if that is the issue. Unless someone has better ideas!!

Very strange!

 

[wouterv]

Not only use a longer cable between your modem and the router, also place them further apart (I suggest 3 feet with your new cable or even a longer distance).

 

[dlandiss]

Well, now I am at least getting somewhere. I just downloaded the Speedtest app for my iPad and ran it and, lo and behold, on my wireless I am getting 178/12! I hadn't checked it before because I assumed if my wired connection wouldn't get it the wireless would be worse. So now I am going to try switching ports to see if that is the issue. Unless someone has better ideas!!

Very strange!

Your success with wireless suggests that the wired connection itself is at fault. That reminded me that while 100BASE-T will work with just 2 of the 4 Ethernet pairs, 1000BASE-T requires all 4 pairs. Can you try it with only 2 cables in the system connected -- modem-to-router and router-to-PC -- and all others unplugged? And make sure both of those have all 8 conductors working.

Again, just a troubleshooting step

 

[RMerlin]

It is very difficult to those speeds on Gigabit LANs

I have no problem moving large files at 100 MB/s between my desktop and my NAS. Just a Cat6 cable (that I actually crimped myself) between both rooms, linking a pair of cheap 30$ TP-Link switches.

 

[Reed Beatse]

That reminded me that while 100BASE-T will work with just 2 of the 4 Ethernet pairs, 1000BASE-T requires all 4 pairs. Can you try it with only 2 cables in the system connected -- modem-to-router and router-to-PC -- and all others unplugged?

Tried and no difference.

And make sure both of those have all 8 conductors working.

I'm sorry but I have no idea what this means.

 

[Reed Beatse]

I switched the cable from the router to the PC from a Cat-5e to a Cat 6 and these are my results, which are about what I have been getting with the other cable (I get 90-100/9-10)

 

[L&LD]

Do you have any other wired clients to test with? Or, can you put a switch between the router and the wired client?

 

[Reed Beatse]

It is a REALLY old laptop but I found it and plugged it in and it got the same results (it was the only thing plugged in).

I do not have a switch. Any more ideas? I am about to give up; there is no way I can convince my wife to buy another router, this one was pricey enough.

 

[L&LD]

For your piece of mind, I would buy (with the intent of returning) and test an RT-AC56U instead (and consider testing a $10 1GbE 4 or 5 port switch too). Or, at the very least try another RT-N66U.

You don't need another router. You just need one that works properly.

Does the router and the wired client indicate an 1GbE connection rate?

 

[RMerlin]

Let's make sure you covered the basics, by starting from the beginning.

1) Replace both the Ethernet cable between modem and router and the one between router and computer
2) Turn off your modem for at least 10 minutes, then turn it back on (this is important when moving a modem back and forth between a router and a PC - the ISP needs to fully "reset" the previous session)
3) Make sure your ISP does not have any special requirements (such as MAC cloning, VLANs or MTU value).
4) Try a different port on the router, in case the port itself is defective
5) Make sure the computer's interface is left on auto-negotiate. Don't try to fix it to 100/1000 manually.
6) Try cloning the MAC, on the WAN configuration page.