What's new

High CPU usage AC68U

  • SNBForums Code of Conduct

    SNBForums is a community for everyone, no matter what their level of experience.

    Please be tolerant and patient of others, especially newcomers. We are all here to share and learn!

    The rules are simple: Be patient, be nice, be helpful or be gone!

Rocketboy235

Regular Contributor
Currently using AC68U with 386.12 Merlin loaded.

Anyone know why dcd may use a lot of CPU usage? Based on what I can find, dcd appears to be related to Trend Micro AiProtection which I do have enabled.
Don't think I've seen this behavior before though but it has been over a 100 days since I last rebooted the router so it may be time. But before I do that, I want to understand better why this is happening if anyone can chime in.

1707525270957.png
1707525813452.png
 
Currently using AC68U with 386.12 Merlin loaded.

Perhaps because DCD crashes and restarts constantly. This bug was fixed in 386.12_2 and then another OpenVPN bug was fixed in 386.12_4. Update your firmware.

 
Ah shoot, I should have checked the changelogs and see if it mentioned anything there... Thank you!
 
It happens. Also your router is perhaps telling you there is a firmware upgrade available.
 
Same issue for me since 386.13 on AC68U. Every few days the router reboots itself (assuming it has been crashing from high CPU usage?). Never had this issue before. Seems like CPU usage is somewhat normal if I stop OpenVPN connection. Memory usage also seems to climb over 1-2 days from under 50% to 90%. VPN usage is pretty light so not sure if that is related. Not sure how to resolve this in the meantime?

Capture.JPG



edit April 14th: Funnily enough I went in to disable traffic analyzer statistics and the router immediately crashed and rebooted. Now I'm not seeing any dcd processes, but not sure if they will return or not in time. I'll keep an eye on it. Also note I still have adaptive qos enabled.
Capture2.JPG


edit April 15th: Crashed again after ~16 hours or so (high CPU usage and unresponsive UI). I'm going to try and disable adaptive QoS and see if that makes any improvement to stability.

edit April 16th: close to 24 hours of uptime with no increase in CPU usage after disabling QoS. I might be speaking too soon but it seems like that was related to my recent crashes.

edit April 17th: I take it back. I'm having issues again with getting logged in to check the status of the router (both via browser and app). Internet speeds are sluggish and web page is not responding at all but no pings are dropping and have not fully crashed yet. Getting pretty tired of this router at this point. After trying again and again for 15+ minutes I was able to get logged in and took a screenshot of the processes. I'm going to reboot and disable everything related to AiProtection. There really isn't much else I can change/disable beyond that now.

Also is it just me or does something not add up here...
Capture3.JPG
 
Last edited:
Well it's been long enough that I would have run into high CPU usage or crashes and everything has been very stable and CPU usage is right where it normally was.

Definitely seems to be an issue with AiProtection - at least with the latest build. I guess I'm going to have to leave all of those features disabled for now (and maybe turn back on QoS and traffic analyzer over time). Hopefully this issue will be resolved in the future because this router has been great for many years otherwise.


And it's happening once again. Just a few hours after I thought it stopped the CPU is through the roof and I can barely get into the web page. I can't even get in to enable ssh to check what processes are running this time.
 
Last edited:
Same here on 386.13. I have done a factory reset with the extra option ticked within the GUI. Shall I try a hardware reset?
 
I've been having the same issue with mine. Though I only have AiProtection on with no other services. I have it reboot once a day and that has fixed the issue.
 
I've been having the same issue with mine. Though I only have AiProtection on with no other services. I have it reboot once a day and that has fixed the issue.
Have you considered turning off all unnecessary stuff, like AIprotection (and withdrawing from the agreement so it shuts down completely), turning off all measurements, etc, so you are just running bare bones? Rebooting once a day is not a solution, it's a bandaid.
 
Have you considered turning off all unnecessary stuff, like AIprotection (and withdrawing from the agreement so it shuts down completely), turning off all measurements, etc, so you are just running bare bones? Rebooting once a day is not a solution, it's a bandaid.

Have you considered turning off all unnecessary stuff, like AIprotection (and withdrawing from the agreement so it shuts down completely), turning off all measurements, etc, so you are just running bare bones? Rebooting once a day is not a solution, it's a bandaid.
Oh I know it's a bandaid. With home many people use my network I wouldn't be running this old of a now EOL router without the AiProtection running. It's twice caught and blocked malicious devices. People love to buy random things off of temu, Alibaba, and Amazon to tinker with....

I'm just waiting for the RT-AX88U Pro to go on sale for ~$200 to replace them.
 
This is not happening on Asuswrt 386_51668 firmware. Something else running around Asuswrt-Merlin must be causing it. Custom script?

There is a new nice surprise after EoL date Asuswrt 386_51685 release with bunch of security fixes and AiMesh update. Wait for updated Asuswrt-Merlin perhaps?
 
Im sorry I should have been more specific. I'm only experiencing the issue of the webui crashing and not restarting if the router is left running for more then a couple of days at a time. Everything still works fine, I just can't access the webui without a reboot.
 
This is not happening on Asuswrt 386_51668 firmware. Something else running around Asuswrt-Merlin must be causing it. Custom script?

There is a new nice surprise after EoL date Asuswrt 386_51685 release with bunch of security fixes and AiMesh update. Wait for updated Asuswrt-Merlin perhaps?

I went to check the Asus eol list, the v3 version still doesn't appear. Does this mean that it will still have some support or not, is it also included in the eol list?
 

Similar threads

Support SNBForums w/ Amazon

If you'd like to support SNBForums, just use this link and buy anything on Amazon. Thanks!

Sign Up For SNBForums Daily Digest

Get an update of what's new every day delivered to your mailbox. Sign up here!
Top