Help diagnosing RT-AC68U losing WAN connection on config changes, Wifi devices connecting, etc...??

[keeena]

TL;DR: router configuration changes, new Wifi device connection to router, etc...seems to kill the router's connection to the WAN. ???

I'm having a new issue with my RT-AC68U which i've owned for years. What initially happened is all my devices (wired and wireless) lost network connectivity. After some testing and troubleshooting: the ISP's (Spectrum) router appears to be OK; I can plug a PC into the modem and it works perfectly fine. The ASUS router was indicating the following error: "Your ISP DHCP is not functioning properly". It also might be important to note that ~1 day prior to this: Spectrum had an outage in my area for a few hours. Everythign worked fine for about 1 day after they restored service (it was not specific to me...was an area outage).

I started debugging with the ISP and they sent a re-provisioning command to the modem. This didn't help, so I tried to connect a PC wired directly to the modem. This worked fine so I focused on the ASUS router. I've performed multiple full factory resets of the ASUS as well as ensured I was on the latest firmware (3.0.0.4.386_43129 which is ~May 2021). I have set the DHCP Query Frequency to Normal (I read an old post which said that the Aggressive mode can sometimes cause problems, but I've never had issues with this for years). I would occasionally get the router to work for short periods but it would drop WAN. I performed some specific testing to highlight when/what causes the ASUS to lose WAN. My steps are commented ### in-line with the ASUS router log.


### STARTING STATE: Modem OK (verified with direct PC->Modem connection). Factory reset ASUS router, configure main WIFI and Admin credentials, verifiy wired connection thru ASUS has network access for aboug 1hr ###
Jun 9 10:34:28 acsd: selected channel spec: 0x1009 (9)
Jun 9 10:34:28 acsd: Adjusted channel spec: 0x1009 (9)
Jun 9 10:34:28 acsd: selected channel spec: 0x1009 (9)
Jun 9 10:34:28 acsd: acs_set_chspec: 0x1009 (9) for reason APCS_CSTIMER
Jun 9 10:34:31 acsd: selected channel spec: 0xe29b (157/80)
Jun 9 10:34:31 acsd: Adjusted channel spec: 0xe29b (157/80)
Jun 9 10:34:31 acsd: selected channel spec: 0xe29b (157/80)
Jun 9 10:34:31 acsd: acs_set_chspec: 0xe29b (157/80) for reason APCS_CSTIMER
Jun 9 10:49:33 acsd: selected channel spec: 0x1008 (8)
Jun 9 10:49:33 acsd: Adjusted channel spec: 0x1008 (8)
Jun 9 10:49:33 acsd: selected channel spec: 0x1008 (8)
Jun 9 10:49:33 acsd: acs_set_chspec: 0x1008 (8) for reason APCS_CSTIMER
Jun 9 10:49:35 acsd: selected channel spec: 0xe29b (157/80)
Jun 9 10:49:35 acsd: Adjusted channel spec: 0xe29b (157/80)
Jun 9 10:49:35 acsd: selected channel spec: 0xe29b (157/80)
Jun 9 10:49:35 acsd: acs_set_chspec: 0xe29b (157/80) for reason APCS_CSTIMER
Jun 9 11:00:47 disk_monitor: Got SIGALRM...
...
Jun 9 11:34:44 acsd: selected channel spec: 0x1008 (8)
Jun 9 11:34:44 acsd: Adjusted channel spec: 0x1008 (8)
Jun 9 11:34:44 acsd: selected channel spec: 0x1008 (8)
Jun 9 11:34:44 acsd: acs_set_chspec: 0x1008 (8) for reason APCS_CSTIMER
Jun 9 11:34:46 acsd: selected channel spec: 0xe22a (44/80)
Jun 9 11:34:46 acsd: Adjusted channel spec: 0xe22a (44/80)
Jun 9 11:34:46 acsd: selected channel spec: 0xe22a (44/80)
Jun 9 11:34:46 acsd: acs_set_chspec: 0xe22a (44/80) for reason APCS_CSTIMER

(to be continued due to length)

 

[keeena]

### CREATE GUEST WIFI ACCOUNT: 2.4ghz, WPA2, all other settings default for wifi. This is a new SSID by-the-way...i'm not re-using any previous SSID. At this point, router drops WAN. ASUS GUI network map it states "Internet status: Disconnected" ###
Jun 9 11:39:20 rc_service: httpd 249:notify_rc restart_wireless;restart_qos;restart_firewall;
Jun 9 11:39:23 kernel: et0: et_mvlan_netdev_event: event 16 for eth0.501 mvlan_en 0
Jun 9 11:39:23 kernel: et0: et_mvlan_netdev_event: event 5 for eth0.501 mvlan_en 0
Jun 9 11:39:23 kernel: et0: et_mvlan_netdev_event: event 13 for eth0.501 mvlan_en 0
Jun 9 11:39:23 kernel: et0: et_mvlan_netdev_event: event 1 for eth0.501 mvlan_en 0
Jun 9 11:39:24 syslog: main(961): wlceventd Start...
Jun 9 11:39:27 acsd: selected channel spec: 0x1009 (9)
Jun 9 11:39:27 acsd: Adjusted channel spec: 0x1009 (9)
Jun 9 11:39:27 acsd: selected DFS-exit channel spec: 0x1009 (9)
Jun 9 11:39:27 acsd: selected channel spec: 0x1009 (9)
Jun 9 11:39:27 acsd: Adjusted channel spec: 0x1009 (9)
Jun 9 11:39:27 acsd: selected channel spec: 0x1009 (9)
Jun 9 11:39:27 acsd: acs_set_chspec: 0x1009 (9) for reason APCS_INIT
Jun 9 11:39:29 acsd: selected channel spec: 0xe02a (36/80)
Jun 9 11:39:29 acsd: Adjusted channel spec: 0xe02a (36/80)
Jun 9 11:39:29 acsd: selected DFS-exit channel spec: 0xe02a (36/80)
Jun 9 11:39:29 acsd: selected channel spec: 0xe02a (36/80)
Jun 9 11:39:29 acsd: Adjusted channel spec: 0xe02a (36/80)
Jun 9 11:39:29 acsd: selected channel spec: 0xe02a (36/80)
Jun 9 11:39:29 acsd: acs_set_chspec: 0xe02a (36/80) for reason APCS_INIT
Jun 9 11:39:40 roamast: ROAMING Start...

### REBOOT MODEM: After the modem reboot, ASUS router GUI reports WAN OK (the first few messages below are during modem come-up and ASUS re-init I assume). ASUS log time jumping around due to temporary TZ unawareness? (I'm in UTC-4) Correct time is the 11:xx, not 15:xx FYI. ####
Jun 9 15:42:19 WAN Connection: ISP's DHCP did not function properly.
Jun 9 15:42:26 WAN Connection: WAN(0) link down.
Jun 9 15:46:16 WAN Connection: WAN(0) link up.
Jun 9 15:46:16 rc_service: wanduck 188:notify_rc restart_wan_if 0
Jun 9 15:46:21 WAN Connection: ISP's DHCP did not function properly.
Jun 9 11:46:22 wan: finish adding multi routes
Jun 9 11:46:22 miniupnpd[2784]: shutting down MiniUPnPd
Jun 9 11:46:22 syslog: it is advised to use network interface name instead of 192.168.1.1/255.255.255.0
Jun 9 11:46:22 miniupnpd[12639]: HTTP listening on port 56740
Jun 9 11:46:22 miniupnpd[12639]: Listening for NAT-PMP/PCP traffic on port 5351
Jun 9 11:46:22 dhcp client: bound 192.168.100.10/255.255.255.0 via 192.168.100.1 for 30 seconds.
Jun 9 15:46:26 WAN Connection: WAN was restored.
Jun 9 15:46:46 WAN Connection: ISP's DHCP did not function properly.
Jun 9 15:46:51 WAN Connection: WAN(0) link up.
Jun 9 15:46:51 rc_service: wanduck 188:notify_rc restart_wan_if 0
Jun 9 15:47:05 WAN Connection: WAN(0) link down.
Jun 9 15:47:10 WAN Connection: WAN(0) link up.
Jun 9 15:47:10 rc_service: wanduck 188:notify_rc restart_wan_if 0
Jun 9 15:47:15 WAN Connection: ISP's DHCP did not function properly.
Jun 9 11:47:16 wan: finish adding multi routes
Jun 9 11:47:16 miniupnpd[12639]: shutting down MiniUPnPd
Jun 9 11:47:16 syslog: it is advised to use network interface name instead of 192.168.1.1/255.255.255.0
Jun 9 11:47:16 miniupnpd[12872]: HTTP listening on port 57663
Jun 9 11:47:16 miniupnpd[12872]: Listening for NAT-PMP/PCP traffic on port 5351
Jun 9 11:47:17 dhcp client: bound xxx.xxx.xxx.xxx/255.255.224.0 via xxx.xxx.xxx.xxx for 76018 seconds.
Jun 9 15:47:20 WAN Connection: WAN was restored.
Jun 9 11:54:31 acsd: selected channel spec: 0x1009 (9)
Jun 9 11:54:31 acsd: Adjusted channel spec: 0x1009 (9)
Jun 9 11:54:31 acsd: selected channel spec: 0x1009 (9)
Jun 9 11:54:31 acsd: acs_set_chspec: 0x1009 (9) for reason APCS_CSTIMER
Jun 9 11:54:34 acsd: selected channel spec: 0xe02a (36/80)
Jun 9 11:54:34 acsd: Adjusted channel spec: 0xe02a (36/80)
Jun 9 11:54:34 acsd: selected channel spec: 0xe02a (36/80)
Jun 9 11:54:34 acsd: acs_set_chspec: 0xe02a (36/80) for reason APCS_CSTIMER

### CONNECT WIFI DEVICE: At this point I connect to the main (not the new Guest) Wifi. Boom ASUS lost connection to WAN again. ASUS GUI network map it states "Internet status: Disconnected". No clear error in the log. The MACs below appear to be the internal MAC of the router (they are not the PC nor iPad i'm testing with, nor are they the MAC of the router or modem) ###
Jun 9 12:03:21 syslog: wlceventd_proc_event(527): eth1: Auth 12:42:xx:xx:xx:xx, status: Successful (0), rssi:0
Jun 9 12:03:21 syslog: wlceventd_proc_event(556): eth1: Assoc 12:42:xx:xx:xx:xx, status: Successful (0), rssi:0
Jun 9 12:03:50 syslog: wlceventd_proc_event(527): eth2: Auth 9E:9A:xx:xx:xx:xx, status: Successful (0), rssi:0
Jun 9 12:03:50 syslog: wlceventd_proc_event(556): eth2: Assoc 9E:9A:xx:xx:xx:xx, status: Successful (0), rssi:0
Jun 9 12:04:29 syslog: wlceventd_proc_event(491): eth1: Deauth_ind 12:42:xx:xx:xx:xx0, status: 0, reason: Disassociated due to inactivity (4), rssi:0

### SHUT DOWN MODEM ###
Jun 9 16:10:25 WAN Connection: ISP's DHCP did not function properly.
Jun 9 16:10:32 WAN Connection: WAN(0) link down.
Jun 9 12:11:08 syslog: wlceventd_proc_event(508): eth2: Disassoc 9E:9A:xx:xx:xx:xx, status: 0, reason: Disassociated because sending station is leaving (or has left) BSS (8), rssi:-51
Jun 9 12:11:10 acsd: selected channel spec: 0xe29b (157/80)
Jun 9 12:11:10 acsd: Adjusted channel spec: 0xe29b (157/80)
Jun 9 12:11:10 acsd: selected channel spec: 0xe29b (157/80)
Jun 9 12:11:10 acsd: acs_set_chspec: 0xe29b (157/80) for reason APCS_CSTIMER

### POWER UP MODEM: ASUS now reports WAN OK. Wired (PC) and wireless (iPad) working OK ###
Jun 9 12:11:18 syslog: wlceventd_proc_event(527): eth2: Auth 9E:9A:xx:xx:xx:xx, status: Successful (0), rssi:0
Jun 9 12:11:18 syslog: wlceventd_proc_event(556): eth2: Assoc 9E:9A:xx:xx:xx:xx, status: Successful (0), rssi:0
Jun 9 16:13:36 WAN Connection: WAN(0) link up.
Jun 9 16:13:36 rc_service: wanduck 188:notify_rc restart_wan_if 0
Jun 9 12:13:42 wan: finish adding multi routes
Jun 9 12:13:42 miniupnpd[12872]: shutting down MiniUPnPd
Jun 9 12:13:42 syslog: it is advised to use network interface name instead of 192.168.1.1/255.255.255.0
Jun 9 12:13:42 miniupnpd[15741]: HTTP listening on port 33551
Jun 9 12:13:43 miniupnpd[15741]: Listening for NAT-PMP/PCP traffic on port 5351
Jun 9 12:13:43 dhcp client: bound 192.168.100.10/255.255.255.0 via 192.168.100.1 for 30 seconds.
Jun 9 16:13:45 WAN Connection: WAN was restored.
Jun 9 16:14:23 WAN Connection: ISP's DHCP did not function properly.
Jun 9 16:14:30 WAN Connection: WAN(0) link up.
Jun 9 16:14:30 rc_service: wanduck 188:notify_rc restart_wan_if 0
Jun 9 12:14:35 wan: finish adding multi routes
Jun 9 12:14:35 miniupnpd[15741]: shutting down MiniUPnPd
Jun 9 12:14:35 syslog: it is advised to use network interface name instead of 192.168.1.1/255.255.255.0
Jun 9 12:14:35 miniupnpd[15939]: HTTP listening on port 40484
Jun 9 12:14:35 miniupnpd[15939]: Listening for NAT-PMP/PCP traffic on port 5351
Jun 9 12:14:36 dhcp client: bound xxx.xxx.xxx.xxx/255.255.224.0 via xxx.xxx.xxx.xxx for 74379 seconds.
Jun 9 16:14:39 WAN Connection: WAN was restored.
Jun 9 12:24:40 acsd: selected channel spec: 0x1004 (4)
Jun 9 12:24:40 acsd: Adjusted channel spec: 0x1004 (4)
Jun 9 12:24:40 acsd: selected channel spec: 0x1004 (4)
Jun 9 12:24:40 acsd: acs_set_chspec: 0x1004 (4) for reason APCS_CSTIMER

### SUMMARY: At this point I'm getting the sense that any router config change, new WIFI device connected, etc..causes the router to lose WAN. I'm not a network guru; hoping someone might be able to shed some light as to why this is happening? ###

 

[AndreiV]

The search facility has plenty of information:

>>> Your ISP DHCP is not functioning properly <<<

The possible answer for your issue :

>>> "DHCP Query Frequency" <<<

 

[keeena]

Thanks AndreiV. I did find some of those suggestions earlier (like DHCP refresh frequency, full wipe, and wait longer than the lease interval). I'll keep poking around.

 

[follower]

TL;DR: router configuration changes, new Wifi device connection to router, etc...seems to kill the router's connection to the WAN. ???

I'm having a new issue with my RT-AC68U which i've owned for years. What initially happened is all my devices (wired and wireless) lost network connectivity. After some testing and troubleshooting: the ISP's (Spectrum) router appears to be OK; I can plug a PC into the modem and it works perfectly fine. The ASUS router was indicating the following error: "Your ISP DHCP is not functioning properly". It also might be important to note that ~1 day prior to this: Spectrum had an outage in my area for a few hours. Everythign worked fine for about 1 day after they restored service (it was not specific to me...was an area outage).

I started debugging with the ISP and they sent a re-provisioning command to the modem. This didn't help, so I tried to connect a PC wired directly to the modem. This worked fine so I focused on the ASUS router. I've performed multiple full factory resets of the ASUS as well as ensured I was on the latest firmware (3.0.0.4.386_43129 which is ~May 2021). I have set the DHCP Query Frequency to Normal (I read an old post which said that the Aggressive mode can sometimes cause problems, but I've never had issues with this for years). I would occasionally get the router to work for short periods but it would drop WAN. I performed some specific testing to highlight when/what causes the ASUS to lose WAN. My steps are commented ### in-line with the ASUS router log.


### STARTING STATE: Modem OK (verified with direct PC->Modem connection). Factory reset ASUS router, configure main WIFI and Admin credentials, verifiy wired connection thru ASUS has network access for aboug 1hr ###
Jun 9 10:34:28 acsd: selected channel spec: 0x1009 (9)
Jun 9 10:34:28 acsd: Adjusted channel spec: 0x1009 (9)
Jun 9 10:34:28 acsd: selected channel spec: 0x1009 (9)
Jun 9 10:34:28 acsd: acs_set_chspec: 0x1009 (9) for reason APCS_CSTIMER
Jun 9 10:34:31 acsd: selected channel spec: 0xe29b (157/80)
Jun 9 10:34:31 acsd: Adjusted channel spec: 0xe29b (157/80)
Jun 9 10:34:31 acsd: selected channel spec: 0xe29b (157/80)
Jun 9 10:34:31 acsd: acs_set_chspec: 0xe29b (157/80) for reason APCS_CSTIMER
Jun 9 10:49:33 acsd: selected channel spec: 0x1008 (8)
Jun 9 10:49:33 acsd: Adjusted channel spec: 0x1008 (8)
Jun 9 10:49:33 acsd: selected channel spec: 0x1008 (8)
Jun 9 10:49:33 acsd: acs_set_chspec: 0x1008 (8) for reason APCS_CSTIMER
Jun 9 10:49:35 acsd: selected channel spec: 0xe29b (157/80)
Jun 9 10:49:35 acsd: Adjusted channel spec: 0xe29b (157/80)
Jun 9 10:49:35 acsd: selected channel spec: 0xe29b (157/80)
Jun 9 10:49:35 acsd: acs_set_chspec: 0xe29b (157/80) for reason APCS_CSTIMER
Jun 9 11:00:47 disk_monitor: Got SIGALRM...
...
Jun 9 11:34:44 acsd: selected channel spec: 0x1008 (8)
Jun 9 11:34:44 acsd: Adjusted channel spec: 0x1008 (8)
Jun 9 11:34:44 acsd: selected channel spec: 0x1008 (8)
Jun 9 11:34:44 acsd: acs_set_chspec: 0x1008 (8) for reason APCS_CSTIMER
Jun 9 11:34:46 acsd: selected channel spec: 0xe22a (44/80)
Jun 9 11:34:46 acsd: Adjusted channel spec: 0xe22a (44/80)
Jun 9 11:34:46 acsd: selected channel spec: 0xe22a (44/80)
Jun 9 11:34:46 acsd: acs_set_chspec: 0xe22a (44/80) for reason APCS_CSTIMER

(to be continued due to length)

Use a new cable.

 

[keeena]

@follower - can you elaborate? I have not changed the setup in years and it's worked fine. This problem only cropped up very recently. But yes: I've already tried that.

FWIW - i'm generally in better shape now that I'm trying Continuous mode, but I still get frequent, ableit short, WIFI drop-outs. I have not setup any tests to see if wired connections are also dropping out.

Curious: is there a reason why there are so many problems with ASUS routers with respect to maintaining connection with the modem? I'm surprised by the volume of posts on the topic. I generally expect these consumer routers to be fairly plug-n-play, but it seems that in some cases some fairly advanced tuning is needed to get them to work. I'm debating replacing this router with a mesh setup for better coverage and I'm concerned about getting another ASUS.

 

[andyross]

I've always wondered why Asus routers seem to have the ISP DHCP issue that others don't. Something about their routines must have a bug, or is too picky about something that others will allow.

 

[L&LD]

Never seen such ISP DHCP issues on any Asus router myself.

How a router is set up and configured initially is the key, I believe, to a stable network.

 

[noah way]

I had a problem with drops on the AC86U in repeater mode. I tried a plethora of settings, switching routers, and even RMA'd one of them. The eventual cure was to flash an older Asus firmware. This fixed the problem. No more drops.

​

3.0.0.4.384_32738

 

[ToriGrace]

Hello, I'm having the exact same issue as described here. Just curious if downgrading the firmware helped? I have an 82u.
And is the firmware described above in quotes the one I need to find?

 

[shibbyshagy]

Very interesting...I have latest ET9 Mesh routers (2 nodes), and have the exactly the same issue. Today I was wired to my router and just googled "acsd: acs_set_chspec: 0x1009 (9) for reason ACS_CSTIMER" and found this post...I have also another Asus router RT-AC3200 and it also has the same issue. I have 2 Linksys routers MR9000 (dual band) and EA6500 and neither of these have this issue. When it happens I can ping my router and no packets drop, but when I ping google.com for example, i see the time outs at the same time my connection drops from a google meeting.

So I do agree with above people, Asus has some weird yet unsolvable logic when it comes to ISP (DHCP) connectivity. When I'm wired directly into my modem, have 0 issues.

You'd think the support people at Asus would be advising of this after 2 months of troubleshooting. I will have to know post this ACS_CSTIMER to them to see what they say. Chances are, "change the cable" or go into WAN setting and change the port, or "its your ISP that is the problem or modem"...