RT-AX86U PRO - CSIMON: M2M usr already registered

[dineshgyl]

Since yesterday I am having issues with 2.4GHz network. All Wifi clients dropping.

I can see my log is flodded with following.

Mar 23 12:14:19 kernel: CSIMON:  CSIMON[1.1.0] Initialization
Mar 23 12:14:19 kernel: CSIMON: M2M usr already registered ...
Mar 23 12:14:37 kernel: CSIMON:  CSIMON[1.1.0] Initialization
Mar 23 12:14:37 kernel: CSIMON: M2M usr already registered ...
Mar 23 12:14:38 hostapd: eth6: STA cc:8c:bf:76:c9:97 IEEE 802.11: disassociated
Mar 23 12:14:38 wlceventd: wlceventd_proc_event(662): eth6: Disassoc CC:8C:BF:76:C9:97, status: 0, reason: Disassociated because sending station is leaving (or has left) BSS (8), rssi:0
Mar 23 12:14:55 kernel: CSIMON:  CSIMON[1.1.0] Initialization
Mar 23 12:14:55 kernel: CSIMON: M2M usr already registered ...
Mar 23 12:15:10 kernel: CSIMON:  CSIMON[1.1.0] Initialization
Mar 23 12:15:10 kernel: CSIMON: M2M usr already registered ...
Mar 23 12:15:15 kernel: CSIMON:  CSIMON[1.1.0] Initialization
Mar 23 12:15:15 kernel: CSIMON: M2M usr already registered ...
Mar 23 12:15:21 kernel: CSIMON:  CSIMON[1.1.0] Initialization
Mar 23 12:15:21 kernel: CSIMON: M2M usr already registered ...
Mar 23 12:15:32 kernel: CSIMON:  CSIMON[1.1.0] Initialization
Mar 23 12:15:32 kernel: CSIMON: M2M usr already registered ...
Mar 23 12:16:00 kernel: CSIMON:  CSIMON[1.1.0] Initialization
Mar 23 12:16:00 kernel: CSIMON: M2M usr already registered ...
Mar 23 12:16:12 kernel: CSIMON:  CSIMON[1.1.0] Initialization
Mar 23 12:16:12 kernel: CSIMON: M2M usr already registered ...
Mar 23 12:16:24 kernel: CSIMON:  CSIMON[1.1.0] Initialization
Mar 23 12:16:24 kernel: CSIMON: M2M usr already registered ...
Mar 23 12:16:38 kernel: CSIMON:  CSIMON[1.1.0] Initialization
Mar 23 12:16:38 kernel: CSIMON: M2M usr already registered ...

I did not make any changes. Router was running fine no reboots since Feb 17.

However yesterday suddenly all of this started coming and I did factory reset and reconfigured everything from scratch.

I am not using anything special. Just normal settings.

Operation Mode:Wireless router Firmware:3004.388.8_4

Please help. Router is new, bought it in Nov 2024.

 

[Twiglets]

Searching these forums for 'CSIMON' there are posts that suggest that USB3 use can impact 2.4Ghz Wireless.
Have you changed something related to USB3 ?

I suggest you search the forums for other hints !!!
[Top righthand search box]

Sorry I cannot offer any more useful advice.

 

[dineshgyl]

I tried that already. No USB connected to the router.

 

[Twiglets]

The other suggestion was to change the 'AUTO' setting on Control Channel to a specific Channel.

Try running the Site Survey ... at http://<Router IP Address>/Advanced_Wireless_Survey.asp
[Set <Router IP Address> as necessary.]

Pick a Channel that is not in major use on the 2.4 GHz band.

 

[CaptainSTX]

Since yesterday I am having issues with 2.4GHz network. All Wifi clients dropping.

I can see my log is flodded with following.

Mar 23 12:14:19 kernel: CSIMON:  CSIMON[1.1.0] Initialization
Mar 23 12:14:19 kernel: CSIMON: M2M usr already registered ...
Mar 23 12:14:37 kernel: CSIMON:  CSIMON[1.1.0] Initialization
Mar 23 12:14:37 kernel: CSIMON: M2M usr already registered ...
Mar 23 12:14:38 hostapd: eth6: STA cc:8c:bf:76:c9:97 IEEE 802.11: disassociated
Mar 23 12:14:38 wlceventd: wlceventd_proc_event(662): eth6: Disassoc CC:8C:BF:76:C9:97, status: 0, reason: Disassociated because sending station is leaving (or has left) BSS (8), rssi:0
Mar 23 12:14:55 kernel: CSIMON:  CSIMON[1.1.0] Initialization
Mar 23 12:14:55 kernel: CSIMON: M2M usr already registered ...
Mar 23 12:15:10 kernel: CSIMON:  CSIMON[1.1.0] Initialization
Mar 23 12:15:10 kernel: CSIMON: M2M usr already registered ...
Mar 23 12:15:15 kernel: CSIMON:  CSIMON[1.1.0] Initialization
Mar 23 12:15:15 kernel: CSIMON: M2M usr already registered ...
Mar 23 12:15:21 kernel: CSIMON:  CSIMON[1.1.0] Initialization
Mar 23 12:15:21 kernel: CSIMON: M2M usr already registered ...
Mar 23 12:15:32 kernel: CSIMON:  CSIMON[1.1.0] Initialization
Mar 23 12:15:32 kernel: CSIMON: M2M usr already registered ...
Mar 23 12:16:00 kernel: CSIMON:  CSIMON[1.1.0] Initialization
Mar 23 12:16:00 kernel: CSIMON: M2M usr already registered ...
Mar 23 12:16:12 kernel: CSIMON:  CSIMON[1.1.0] Initialization
Mar 23 12:16:12 kernel: CSIMON: M2M usr already registered ...
Mar 23 12:16:24 kernel: CSIMON:  CSIMON[1.1.0] Initialization
Mar 23 12:16:24 kernel: CSIMON: M2M usr already registered ...
Mar 23 12:16:38 kernel: CSIMON:  CSIMON[1.1.0] Initialization
Mar 23 12:16:38 kernel: CSIMON: M2M usr already registered ...

I did not make any changes. Router was running fine no reboots since Feb 17.

However yesterday suddenly all of this started coming and I did factory reset and reconfigured everything from scratch.

I am not using anything special. Just normal settings.

Operation Mode:Wireless router Firmware:3004.388.8_4

View attachment 64525

View attachment 64526

Please help. Router is new, bought it in Nov 2024.

Try downgrading the modulation scheme one step at a time to see if that helps. IoT devices in particular seem to have the most problems connecting and staying connected to 2.4 Ghz radios with all the bells and whistles enbled. I am getting to the point where for certain IoT devices I have them connecting to an old travel router of mine that has a single N radio running and run it as AP off a LAN port from my AX88 Pro that is on its own VLAN/subnet. Once Merlin has a stable release version of the firmware for the AX88 Pro I may try downgrading it to the lowest modulation scheme (N) on the 2.4 Ghz radio as all the devices that need greater bandwidth either already connect to the 5 Ghz radio or Ethernet.

 

[dineshgyl]

Thanks will take a look. As of now, it started working fine after reboot of router but not sure how long it will work for.

 

[Spinnek]

It seems that I found a correlation between the CSIMON and "M2M usr already registered" messages in case the 5Ghz Wireless band is used.

When you use 5 Ghz DFS channels, there is some kind of monitoring of DFS channels started in the background:

[Wireless Router] What is DFS (Dynamic Frequency Selection) and how does it work on ASUS router? | Official Support | ASUS Global

My theory is as follows (logs taken from the RT-AX55 router, software version 3.0.0.4.386_53244):
Whenever that monitoring process detects some kind of interference on ANY of the (usually) several DFS channels the router is using, that could be a military radar, a satellite communication, or a weather radar, it stops transmission on ALL the 5Ghz DFS channels it was previously used and logs the messages as follows:

Aug 21 19:07:30 kernel: CSIMON: CSIMON[1.1.0] Initialization
Aug 21 19:07:30 kernel: CSIMON: M2M usr already registered ...
followed by the series of Deauth_ind messages
Aug 21 19:07:33 wlceventd: wlceventd_proc_event(494): eth3: Deauth_ind xx, status: 0, reason: Disassociated due to inactivity (4), rssi:-67
[...]

I my case, after about 20 seconds the router was able to reconnect wireless clients:
Aug 21 19:07:51 wlceventd: wlceventd_proc_event(530): eth3: Auth xx, status: Successful (0), rssi:-81
[...]

But, at the same time of the CSIMON and "M2M usr already registered" messages were logged, the following parameter was zeroized:

DFS status: state In-Service Monitoring(ISM) time elapsed XYZ ms radar channel cleared by DFS channel [xx/80]

My router didn't change the channels after such interference, so I think it was not able to confirm that the interference was similar to to programmed profile of a military radar, a satellite communication, or a weather radar.

***

This behavior could be the root cause of the ASUS (and certainly, the others as well) routers' behavior using the DFS channels, that could be perceived as router failure, because SUDDENLY the routers start randomly to behave erratically, logging never mentioned CSIMON and "M2M usr already registered" messages, whereas they are just doing their proper job, detecting random interferences.