Huge CPU load

[deefop]

Hi all

So I have an RT-AC66W that I've been running dd-wrt on for a while. A couple days ago I switched to the newest MerlinWRT build. I had a bunch of friends over today for a LAN party, and once everybody got connected the CPU load spiked and the router effectively crashed to the ground.

I had to go into the settings and disable QoS(since I'm a gamer I really want QoS up and running effectively, which it more or less was with DD-WRT). I also enabled hardware NAT. And apparently you can't use hardware NAT with QoS? That wouldn't bug me except that under DD-WRT I've literally always had QoS enabled and never once run into problems with the router being unable to handle WAN routing or maxing out the CPU.

It seems to be working OK under those settings, but I'm still confused. Less than 10 clients should not crash a router with this level of hardware. I've had bigger LAN parties with my old Buffalo HP-G300N(I think I go that model right) running DD-WRT.

Did I do something wrong? I'm kind of thinking about just jumping back to DD-WRT after this experience. Not because I need fancy enterprise level feature sets, but because I do need a stable router with some form of QoS.

Thanks in advance for any advice!

 

[Vexira]

did you factory reset after switching from ddwrt? if you haven't that's going to be an issue, hard ware nat does work only CTF (cut though forwarding), where as flow acceleration doesn't work.

 

[deefop]

did you factory reset after switching from ddwrt? if you haven't that's going to be an issue, hard ware nat does work only CTF (cut though forwarding), where as flow acceleration doesn't work.

I did factory reset after the switch, multiple times in fact because I had to put the router in recovery mode after a bad DD-WRT upgrade attempt.

Based on another thread I've now seen on these forums, I think there's an issue with the most recent Asus-WRT builds. So apparently there's no fix in site, and I can't use FQ_Codel with those firmware/router either.

I guess it was just an unlucky time for me to give it a try.

 

[Jack Yaz]

I have to chime in here. I actually reset my 87U on .67 and am now on .68. Adaptive QoS shaves my speed from 220Mb/s to 160Mb/s, with a higher CPU load than .67.

While 160Mb/s is plenty, I'm another case of me too!

 

[deefop]

I have to chime in here. I actually reset my 87U on .67 and am now on .68. Adaptive QoS shaves my speed from 220Mb/s to 160Mb/s, with a higher CPU load than .67.

While 160Mb/s is plenty, I'm another case of me too!

But .67 was working ok for you?

I think your router has a couple features mine doesn't have as well, I don't have an option for adaptive QoS for example. I just have traditional QoS and bandwidth limiting.

 

[Jack Yaz]

But .67 was working ok for you?

I think your router has a couple features mine doesn't have as well, I don't have an option for adaptive QoS for example. I just have traditional QoS and bandwidth limiting.

Indeed it was. I also use a script to enhance adaptive QoS. I've found turning off the switch gets me about 190, so an improvement, but still less than .67. CPU hits 100% on core 1 and about 50% on 2, so I have some room for manoeuvre.

 

[deefop]

Indeed it was. I also use a script to enhance adaptive QoS. I've found turning off the switch gets me about 190, so an improvement, but still less than .67. CPU hits 100% on core 1 and about 50% on 2, so I have some room for manoeuvre.

Yea with your beefier hardware it probably doesn't go totally ash-can if you have a bunch of people connected to it.

Yesterday with mine I had to literally have everybody else disconnect just to bring the CPU load low enough to get into the router and make the necessary changes.

If .67 was totally normal would it be a pain to go back to it? Can I just upgrade it through the interface like any other normal firmware upgrade or is going backwards a problem?

 

[Jack Yaz]

Yea with your beefier hardware it probably doesn't go totally ash-can if you have a bunch of people connected to it.

Yesterday with mine I had to literally have everybody else disconnect just to bring the CPU load low enough to get into the router and make the necessary changes.

If .67 was totally normal would it be a pain to go back to it? Can I just upgrade it through the interface like any other normal firmware upgrade or is going backwards a problem?

As far as I'm aware, you can just flash .67 on top. Factory reset post flashing is probably worth doing as well.