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Serious Bugs for the AC66U

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Wilkie

Occasional Visitor
I already used the Asus AC66U 2 more years, I always used the official firmwares and keep the latest version before. Recently I converted the official firmware to the Merlin, but I found the following 2 serial bugs are still existed on all of firmwares with any versions. Anybody can help? thank you in advanced. My current firmware version is 378.51 with Merlin.
1. Whatever the offcial firmware or Merlin, sometimes the AC66U seem like hang but not fully dead, I still can login on the router by SSH or WebGUI with very slow latency, and I typed some commands to check the performance and system logs, but no any findings, CPU/Memory utilization were normal, no special error logs, but all of devices accessed internet very very slow, the whole router works very slow too, the only solution is rebooting. After rebooting, anything will be ok, the issue happened frequently, especially there were too many data stream between the router and internet;
2. For the 2nd issue, I'm not sure that it is a firmware issue, maybe it is caused by the Asus site, the Asus Official DDNS, there are too many errors as the below, and the DDNS service can't be used til now.
Mar 19 21:18:13 watchdog: start ddns.
Mar 19 21:18:13 rc_service: watchdog 415:notify_rc start_ddns
Mar 19 21:18:13 ddns update: ez-ipupdate: starting...
Mar 19 21:18:58 ddns update: error connecting to ns1.asuscomm.com:80
Mar 19 21:18:58 ddns update: asusddns_update: 1
 
Have you reset the router to factory defaults and then manually and minimally configured it to secure and connect to your ISP after you flashed the firmware?
 
Have you reset the router to factory defaults and then manually and minimally configured it to secure and connect to your ISP after you flashed the firmware?
Yes, I already did this when updated the 378.49 to 378.50, but the issue is still existed ,I only can recovery this by rebooting, and this just happened again 20 mins ago
 
I think you need to do it again.
 
I've had my AC66U for about a year, moved to Merlin in May of last year and installed all Merlin builds ever since and it's always been rock solid.

I don't use WiFi (disabled both radios), NAT acceleration or NAT loopback but I have a few firewall rules (which don't work) and quite a lot of devices connected through 3 switches (so I also disabled Spanning Tree): NAS, Time Machine as WiFI AP, TV, phone, Dune HD and a few computers, phones and tablets.

So the only issue I have is with firewall rules which just don't work at all in the time period I defined them (block Minecraft between 22:00 - 06:00 on week days) and it seems this may be the due to using 378 on the AC66U (which is not available from Asus and may be the reason why (according to some other forum posts))
 
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Yes, I already did this when updated the 378.49 to 378.50, but the issue is still existed ,I only can recovery this by rebooting, and this just happened again 20 mins ago
What about heat? Is it in an area that perhaps its getting hot or limited air flow? Are the vents clogged with dust and dirt? Lots of folks here use those laptop cooling pads and set their routers on them. Works well and drops the temps a good 10c.
 
Marc66, I don't think firewall rules would work with NAT disabled.
 
Marc66, I don't think firewall rules would work with NAT disabled.
Which NAT? NAT acceleration or NAT loopback?
Outgoing NAT is always enabled, otherwise my router would not differentiate the internal clients and keep track of their traffic
NAT acceleration is just using another chip than the CPU, so there should be no impact here either
NAT loopback is irrelevant since I'm not connecting back to an internal machine
 
Which NAT? NAT acceleration or NAT loopback?
Outgoing NAT is always enabled, otherwise my router would not differentiate the internal clients and keep track of their traffic
NAT acceleration is just using another chip than the CPU, so there should be no impact here either
NAT loopback is irrelevant since I'm not connecting back to an internal machine
Disable the NAT can resolve this issue?
 
Honestly, the one and only way to tell is to get another router to test. It might be your router has hardware problem, or someone DDoS-ing you, or your ISP is not behaving well (which a reboot might re-establish the connection), etc. Given lots of people are still running AC66U absolutely fine, it's something very very unique in your situation and it would be extremely difficult to diagnose with just a forum thread.
 
During these days, I think I maybe worked out the solution and the root cause, this maybe was caused by Qos, it should be a bug. After I disabled the Qos, whatever I tested the router, the issue never happen again til now, but I am not sure about this? Anybody has ideals?
 
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I think you might have found it. I sometime had that slow to crawl admin gui, tablet disconnected and top on server show a process bouncing between 15 and 25% (can't remember that process name). But that was long time ago. I have since switched from adsl 5 (pppoe) to faster cable 15 (automatic ip), so I don't use qos anymore with zero problem.
... not sure if my rare intermittent problem has root cause pppoe or qos.
 
I think you might have found it. I sometime had that slow to crawl admin gui, tablet disconnected and top on server show a process bouncing between 15 and 25% (can't remember that process name). But that was long time ago. I have since switched from adsl 5 (pppoe) to faster cable 15 (automatic ip), so I don't use qos anymore with zero problem.
... not sure if my rare intermittent problem has root cause pppoe or qos.
Thanks for your help, the issue only not happened for several days, I am still not sure the issue is resolved absolutely, maybe something will triggerred this again. The issue really trouble me for a long time, so boring!!!!
 
What about heat? Is it in an area that perhaps its getting hot or limited air flow? Are the vents clogged with dust and dirt? Lots of folks here use those laptop cooling pads and set their routers on them. Works well and drops the temps a good 10c.
The temperature is ok, I can check this on the WebGUI, anything looks well
 

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