RT-68U loses dns resolution

[MLaf]

Running stock firmware, every so often (usually in the middle of the night ) the router loses the ability to resolve hostnames (either on the client side or directly from the router).
What I discovered as a quick fix is toggling the WAN DNS settings to a different set of resolvers. This seems to kickstart it back working.
Has anyone seen similar issues that were possibly firmware related? (I’ve gone through periods of this happening frequently to none at all and I’m guessing it was due to different firmware releases but never looked too much into it. I usually keep the device updated )

I haven’t switched to Merlin yet but wondering if maybe I should. I also don’t have much time to test or troubleshoot when it is happening because 99% of the time my wife or myself need to get connected to work. Since I know the quick fix I just do that.

 

[OzarkEdge]

Running stock firmware, every so often (usually in the middle of the night ) the router loses the ability to resolve hostnames (either on the client side or directly from the router).
What I discovered as a quick fix is toggling the WAN DNS settings to a different set of resolvers. This seems to kickstart it back working.
Has anyone seen similar issues that were possibly firmware related? (I’ve gone through periods of this happening frequently to none at all and I’m guessing it was due to different firmware releases but never looked too much into it. I usually keep the device updated )

I haven’t switched to Merlin yet but wondering if maybe I should. I also don’t have much time to test or troubleshoot when it is happening because 99% of the time my wife or myself need to get connected to work. Since I know the quick fix I just do that.

Does it also happen with different, non-ISP DNS?

How old is the router... about two weeks before my AC86U burned out, it had intermittant trouble resolving URLs. I was glad when it fully died... I redeployed its brother node to router duty and the URL issued was resolved.

OE

 

[MLaf]

Does it also happen with different, non-ISP DNS?

How old is the router... about two weeks before my AC86U burned out, it had intermittant trouble resolving URLs. I was glad when it fully died... I redeployed its brother node to router duty and the URL issued was resolved.

OE

Yeah it doesn't matter what the current DNS settings are (whether it's ISP issued, or something like Google or Cloudflare). It's the toggling the change that fixes it.
Oh I have no idea how old it is... maybe 5 years?

Here's part of the system log for today (since midnight). We discovered it not working right before 7:00am and I fixed it around 7:29 (marked in the log below). It's been up ever since.
I'm wondering if the WATCHDOG: [FAUPGRADE] event had anything to do with it? I'm not up at 2:00am to check but that's the only thing that's different. I deleted a bunch of the wlceventd_proc_event entries for wireless devices leaving and joining as it wouldn't let me post the whole thing.

I also disabled QoS this morning to see if that changes anything but I don't know if it will... since no one is using anything in the middle of the night and that's when it goes off into never never land.

Jul 27 01:34:10 syslog: wlceventd_proc_event(494): eth1: Deauth_ind 08:8E:DC:D5:0E:EC, status: 0, reason: Disassociated due to inactivity (4), rssi:0
Jul 27 01:34:22 syslog: wlceventd_proc_event(530): eth1: Auth 08:8E:DC:D5:0E:EC, status: Successful (0), rssi:0
...
Jul 27 02:12:06 WATCHDOG: [FAUPGRADE][auto_firmware_check:(7784)]do webs_update
Jul 27 02:12:17 WATCHDOG: [FAUPGRADE][auto_firmware_check:(7802)]retrieve firmware information
Jul 27 02:12:17 WATCHDOG: [FAUPGRADE][auto_firmware_check:(7817)]fimrware update check first time
Jul 27 02:12:17 WATCHDOG: [FAUPGRADE][auto_firmware_check:(7848)]no need to upgrade firmware
Jul 27 02:12:47 WATCHDOG: [FAUPGRADE][auto_firmware_check:(7784)]do webs_update
Jul 27 02:12:47 WATCHDOG: [FAUPGRADE][auto_firmware_check:(7802)]retrieve firmware information
Jul 27 02:12:47 WATCHDOG: [FAUPGRADE][auto_firmware_check:(7822)]fimrware update check once
Jul 27 02:13:17 WATCHDOG: [FAUPGRADE][auto_firmware_check:(7784)]do webs_update
Jul 27 02:13:17 WATCHDOG: [FAUPGRADE][auto_firmware_check:(7802)]retrieve firmware information
Jul 27 02:13:17 WATCHDOG: [FAUPGRADE][auto_firmware_check:(7822)]fimrware update check once
Jul 27 02:13:47 WATCHDOG: [FAUPGRADE][auto_firmware_check:(7784)]do webs_update
Jul 27 02:13:47 WATCHDOG: [FAUPGRADE][auto_firmware_check:(7802)]retrieve firmware information
Jul 27 02:13:47 WATCHDOG: [FAUPGRADE][auto_firmware_check:(7817)]fimrware update check first time
Jul 27 02:13:47 WATCHDOG: [FAUPGRADE][auto_firmware_check:(7848)]no need to upgrade firmware
Jul 27 02:23:08 rc_service: rc 1419:notify_rc restart_wrs
Jul 27 02:23:33 BWDPI: fun bitmap = 4df
Jul 27 02:23:33 A.QoS: qos_count=0, qos_check=0
Jul 27 03:31:10 syslog: wlceventd_proc_event(494): eth1: Deauth_ind 08:8E:DC:D5:0E:EC, status: 0, reason: Disassociated due to inactivity (4), rssi:0
Jul 27 03:31:15 syslog: wlceventd_proc_event(530): eth1: Auth 08:8E:DC:D5:0E:EC, status: Successful (0), rssi:0
...
Jul 27 05:06:32 ahs: [read_json]Update ahs JSON file.
Jul 27 05:17:10 syslog: wlceventd_proc_event(494): eth1: Deauth_ind 08:8E:DC:D5:0E:EC, status: 0, reason: Disassociated due to inactivity (4), rssi:0
Jul 27 05:17:12 syslog: wlceventd_proc_event(530): eth1: Auth 08:8E:DC:D5:0E:EC, status: Successful (0), rssi:0

### ME FIXING IT ###

Jul 27 07:28:50 rc_service: httpd 578:notify_rc restart_wan_if 0;restart_stubby
Jul 27 07:28:57 wan: finish adding multi routes
Jul 27 07:28:58 miniupnpd[4761]: shutting down MiniUPnPd
Jul 27 07:29:00 syslog: it is advised to use network interface name instead of 192.168.1.1/255.255.255.0
Jul 27 07:29:00 miniupnpd[32337]: HTTP listening on port 57367
Jul 27 07:29:00 miniupnpd[32337]: Listening for NAT-PMP/PCP traffic on port 5351
Jul 27 07:29:11 rc_service: httpd 578:notify_rc restart_wan_if 0;restart_stubby
Jul 27 07:29:19 wan: finish adding multi routes
Jul 27 07:29:20 miniupnpd[32337]: shutting down MiniUPnPd
Jul 27 07:29:21 syslog: it is advised to use network interface name instead of 192.168.1.1/255.255.255.0
Jul 27 07:29:21 miniupnpd[32540]: HTTP listening on port 42159
Jul 27 07:29:21 miniupnpd[32540]: Listening for NAT-PMP/PCP traffic on port 5351
Jul 27 07:29:26 kernel:  *** ERROR: [tdts_shell_ioctl_sig_op_load:95] tdts_core_rule_parsing_trf_load() fail!
Jul 27 07:29:28 BWDPI: fun bitmap = 4df
Jul 27 07:29:28 A.QoS: qos_count=0, qos_check=0
Jul 27 07:29:34 dhcp client: bound 108.162.167.137/255.255.255.224 via 108.162.167.129 for 3578 seconds.
Jul 27 07:29:35 BWDPI: fun bitmap = 4df
Jul 27 07:29:35 A.QoS: qos_count=0, qos_check=0
Jul 27 07:29:35 kernel: ERR[parse_qos_conf:939] Can't set new QoS conf while QoS is started!
Jul 27 07:29:35 kernel: ERR[ioctl_iqos_op_config:3608] parse qos_conf error!!
Jul 27 07:29:35 kernel: ioctl_iqos_op_config() fail!
Jul 27 07:29:35 A.QoS: set_qos_conf fails
Jul 27 07:29:35 A.QoS: restart A.QoS because set_qos_conf / set_qos_on / setup rule fail
Jul 27 07:29:36 A.QoS: qos_count=0, qos_check=1
Jul 27 07:29:40 A.QoS: qos rule is less than 22
Jul 27 07:29:40 A.QoS: restart A.QoS because set_qos_conf / set_qos_on / setup rule fail
Jul 27 07:29:41 dhcp client: bound 108.162.167.137/255.255.255.224 via 108.162.167.129 for 3578 seconds.
Jul 27 07:31:18 rc_service: cfg_server 3987:notify_rc restart_qos;restart_firewall;
Jul 27 07:31:45 BWDPI: fun bitmap = 45f
Jul 27 07:41:10 syslog: wlceventd_proc_event(494): wl0.1: Deauth_ind D6:E1:0E:44:EA:BA, status: 0, reason: Disassociated due to inactivity (4), rssi:0
Jul 27 07:41:12 syslog: wlceventd_proc_event(530): wl0.1: Auth D6:E1:0E:44:EA:BA, status: Successful (0), rssi:0
Jul 27 07:41:13 syslog: wlceventd_proc_event(530): wl0.1: Auth D6:E1:0E:44:EA:BA, status: Successful (0), rssi:0
Jul 27 07:41:13 syslog: wlceventd_proc_event(559): wl0.1: Assoc D6:E1:0E:44:EA:BA, status: Successful (0), rssi:0

 

[MLaf]

Forgot to post Firmware version

3.0.0.4.386_49703-gc2cdfc8

 

[OzarkEdge]

Forgot to post Firmware version

3.0.0.4.386_49703-gc2cdfc8

Given current firmware on an older router, have you reset the firmware and configured it from scratch lately? If not, I would do that to rule out firmware upgrade gremlins... and keep it minimally configured at first to see how it behaves before adding on stuff.

Reset FAQ
Reset via Reset button/webUI Restore/node removal - clears settings in NVRAM; reboot restores fw defaults from CFE (fw defaults)
Hard Reset via WPS button/webUI Restore+Initialize - also clears data logged in /jffs partition (fw defaults+clear logs)
Restoration - uploads fw in Rescue Mode

OE

 

[MLaf]

Given current firmware on an older router, have you reset the firmware and configured it from scratch lately? If not, I would do that to rule out firmware upgrade gremlins... and keep it minimally configured at first to see how it behaves before adding on stuff.

Reset FAQ
Reset/webUI Restore - clear settings in NVRAM; reboot restores fw defaults from CFE (fw defaults)
Hard Reset/webUI Restore+Initialize - also clear data logged in /jffs partition (fw defaults+clear logs)
Restoration - upload fw in Rescue Mode

OE

No I haven't reset it (I figured the next time I would do that would be when switching to Merlin but the opportunity hasn't come up yet).

It is pretty minimally configured but I guess that wouldn't hurt - the crappy thing is that this doesn't happen every night (it's been twice in the past week but before that I can't even remember when it did it).

Is there any extra logging built in that I might be able to see or enable? The system log in the GUI doesn't appear to be very helpful for this issue. Haven't ssh'd into the device yet to look around.

 

[OzarkEdge]

No I haven't reset it (I figured the next time I would do that would be when switching to Merlin but the opportunity hasn't come up yet).

It is pretty minimally configured but I guess that wouldn't hurt - the crappy thing is that this doesn't happen every night (it's been twice in the past week but before that I can't even remember when it did it).

Is there any extra logging built in that I might be able to see or enable? The system log in the GUI doesn't appear to be very helpful for this issue. Haven't ssh'd into the device yet to look around.

If you have not reset the firmware lately, I would do that before any troubleshooting. And don't restore a saved configuration.

Takes me about 20 minutes to clean install the firmware using my install notes, if you need a baseline configuration reference.

OE

 

[MLaf]

If you have not reset the firmware lately, I would do that before any troubleshooting. And don't restore a saved configuration.

Takes me about 20 minutes to clean install the firmware using my install notes, if you need a baseline configuration reference.

OE

Sounds good - will try to do that tonight when no one is requiring the internet.

Just to be clear, you're recommending just a factory reset (from web gui)? Or are you suggesting more things outside of this?

 

[OzarkEdge]

Sounds good - will try to do that tonight when no one is requiring the internet.

Just to be clear, you're recommending just a factory reset (from web gui)? Or are you suggesting more things outside of this?

Given the latest firmware is already installed, reset it using the webUI Restore+Initialize; then configure it from scratch. That's all... monitor the LEDs and wait for them/the router to settle whenever required before proceeding... slow but sure.

OE

 

[MLaf]

Given the latest firmware is already installed, reset it using the webUI Restore+Initialize; then configure it from scratch. That's all... monitor the LEDs and wait for them/the router to settle whenever required before proceeding... slow but sure.

OE

Alright will do, thank you! I'll post back in a week or so after I've given it time.

 

[MLaf]

FYI - Reset tonight and reconfigured everything manually. So far so good (everything came back up and is working). Fingers crossed this fixes the issue! But only time will tell.

 

[MLaf]

@OzarkEdge so I discovered a weird issue since the reset. Every device works fine except my Surface Laptop when on the 2.4GHz network. 5 works fine but the area in the house where I work the signal is poor so I typically use 2.4. Ever since the reset I can barely do anything while on 2.4. DNS sometimes resolves, things frequently timeout. Can’t even connect to my offices vpn. I saw a note in the stickied posts about some Macs having issues with 2.4 and there were a few commands that could be run to fix this but I wasn’t sure if it applied to non-Macs (or even what the commands did). We do have 2 Macs in the house that seem to be fine.

 

[MLaf]

@OzarkEdge ah fixed it! When I was resetting the router last night I saw that the 2.4 GHz band had an option to disable 11b (and I know I don't have any 11b devices around) so I figured I'd just check that box... and as soon as I unchecked it everything started working great. I also seem to recall YEARS ago having a similar issue with a Linksys router in that certain devices would perform extremely poorly when 11b was disabled. So that's fixed but I'm very curious as to why.

 

[OzarkEdge]

@OzarkEdge ah fixed it! When I was resetting the router last night I saw that the 2.4 GHz band had an option to disable 11b (and I know I don't have any 11b devices around) so I figured I'd just check that box... and as soon as I unchecked it everything started working great. I also seem to recall YEARS ago having a similar issue with a Linksys router in that certain devices would perform extremely poorly when 11b was disabled. So that's fixed but I'm very curious as to why.

Not sure... maybe the 2.4 client is only able to use 11b reliably due to some client issue or other interference. Or maybe the router radio is having some limitation with non-11b usage, forcing the fallback to 11b... higher data rates can stress marginal circuits. 11b is not a good 'fix' with presumably current/capable clients. I would want to rule out the router (try another router), rule out the client (observe other 2.4 clients), and beware any close cordless devices (mice, headphones, etc.) using the 2.4GHz band that could be interfering with the 2.4 WiFi.

It should just work without special settings... you may still have a router hardware issue... a marginal circuit causing wierdness like DNS resolution and now seemingly forcing 11b usage with modern hardware (query the 2.4 client connection status to see what link protocol it is using from various locations).

This is not to suggest a forklift upgrade to a new router... but a new router would provide better WiFi to your fringe client/work-from-home office. At some point you may want to consider the opportunity cost of continuing with the AC68U, if it remains suspect.

And see if the DNS issue continues...

OE

 

[MLaf]

Not sure... maybe the 2.4 client is only able to use 11b reliably due to some client issue or other interference. Or maybe the router radio is having some limitation with non-11b usage, forcing the fallback to 11b... higher data rates can stress marginal circuits. 11b is not a good 'fix' with presumably current/capable clients. I would want to rule out the router (try another router), rule out the client (observe other 2.4 clients), and beware any close cordless devices (mice, headphones, etc.) using the 2.4GHz band that could be interfering with the 2.4 WiFi.

It should just work without special settings... you may still have a router hardware issue... a marginal circuit causing wierdness like DNS resolution and now seemingly forcing 11b usage with modern hardware (query the 2.4 client connection status to see what link protocol it is using from various locations).

This is not to suggest a forklift upgrade to a new router... but a new router would provide better WiFi to your fringe client/work-from-home office. At some point you may want to consider the opportunity cost of continuing with the AC68U, if it remains suspect.

And see if the DNS issue continues...

OE

I looked at the client info (Windows built in statistics) and it does indicate using 802.11n so I don't think it's actually using b. Are there any more advanced statistics I can pull from the router to see what link protocol it says they're using or can you recommend a more verbose tool I can load on the client?

Oddly enough I was looking at newer routers and not sure if I can justify to the powers-at-be for spending almost $400 on a new router.... :-/ (AX86U). My plan was always to relocate the device but still haven't figured that part out yet (Our internet connection isn't faster than the speeds that the wireless network provides so it's not like it's a protocol causing a bottleneck...).

If the dns resolution issues clears up after this reset then I'm good until it totally craps out... Still might switch to Merlin if it brings any benefits to me.

 

[OzarkEdge]

I looked at the client info (Windows built in statistics) and it does indicate using 802.11n so I don't think it's actually using b. Are there any more advanced statistics I can pull from the router to see what link protocol it says they're using or can you recommend a more verbose tool I can load on the client?

Oddly enough I was looking at newer routers and not sure if I can justify to the powers-at-be for spending almost $400 on a new router.... :-/ (AX86U). My plan was always to relocate the device but still haven't figured that part out yet (Our internet connection isn't faster than the speeds that the wireless network provides so it's not like it's a protocol causing a bottleneck...).

If the dns resolution issues clears up after this reset then I'm good until it totally craps out... Still might switch to Merlin if it brings any benefits to me.

Sounds reasonable.

The router Wireless Log lists client connection details by MAC address. You can see the client connection wireless mode there.

$400 is too much, imo. $250 is a stretch (the new normal?). $150 pre-pandemic was nice. Also depends on the tax(es) in one's country... gotta pay for social costs somehow.

OE

 

[MLaf]

Sounds reasonable.

The router Wireless Log lists client connection details by MAC address. You can see the client connection wireless mode there.

$400 is too much, imo. $250 is a stretch (the new normal?). $150 pre-pandemic was nice. Also depends on the tax(es) in one's country... gotta pay for social costs somehow.

OE

Yeah they're $360CAD (after taxes it's over $400).... damn useless wooden nickels...

Associated Authorized   RSSI PHY PSM SGI STBC Tx rate Rx rate Connect Time
Yes        Yes        -69dBm n   No  Yes Yes   144.4M  115.6M     02:43:43

That's for my laptop. (Not sure if the code block does monospace so that might look butchered.

 

[OzarkEdge]

Yeah they're $360CAD (after taxes it's over $400).... damn useless wooden nickels...

Associated Authorized   RSSI PHY PSM SGI STBC Tx rate Rx rate Connect Time
Yes        Yes        -69dBm n   No  Yes Yes   144.4M  115.6M     02:43:43

That's for my laptop. (Not sure if the code block does monospace so that might look butchered.

So, that 2-stream/antenna wireless-n client is getting full link rate (144Mbps) at just less than a target RSSI of -65dBm... about as good as to be expected. Actual throughput speed will depend on sustaining link Tx/Rx rates over time in the presense of other Wifi users, etc. WiFi is shared and half-duplex... one transmission in one direction in time, including your neighbors' clients using the same radio frequencies.

OE

 

[MLaf]

So, that 2-stream/antenna wireless-n client is getting full link rate at just less than a target RSSI of -65dBm... about as good as to be expected. Actual throughput speed will depend on sustaining link Tx/Rx rates over time in the presense of other Wifi users, etc.

OE

Yeah I'm not complaining about the speeds or stability with this connection (it was just absolute garbage when I specifically disabled 11b). Shrug...

Mind you everyone just experienced a disconnect and reconnect maybe 10 minutes ago so perhaps it is time to go shopping :-(.

Maybe I can look at just the AX68U instead of the 86. The house isn't big and I do have decent (not perfect) coverage (even outside where I am right now) on the 2.4 radio with the AC68U. Doesn't seem to be much interference from the neighbours...

If I could relocate the router more central I'd have no issues with coverage from a less powerful device... and there's only 3 of us in the house with the most bandwidth from Netflix or video conferencing.

 

[OzarkEdge]

Yeah I'm not complaining about the speeds or stability with this connection (it was just absolute garbage when I specifically disabled 11b). Shrug...

Mind you everyone just experienced a disconnect and reconnect maybe 10 minutes ago so perhaps it is time to go shopping :-(.

Maybe I can look at just the AX68U instead of the 86. The house isn't big and I do have decent (not perfect) coverage (even outside where I am right now) on the 2.4 radio with the AC68U. Doesn't seem to be much interference from the neighbours...

If I could relocate the router more central I'd have no issues with coverage from a less powerful device... and there's only 3 of us in the house with the most bandwidth from Netflix or video conferencing.

A WiFi analyzer app can be useful to 'see' the signals to see if they are relatively stable or dropping out... they should appear stable when in range. Weird behavior may suggest a radio/hardware issue.

OE