Clients connected to Asus AC66U in AP mode no internet

[KFL]

Hi I have the following network topology at home.

The main router is a DLink (192.168.0.1). The Asus AC66U (192.168.0.2 via DHCP reservation from DLink) is setup to be in AP mode. It is using ASUSWRT-Merlin RT-AC66U 380.65-4

Intermitently, clients connected to AC66U lose internet connection. When either Dlink or AC66U is rebooted, the problem goes away (temporarily). This happens multiple times during a day.

My observation when this happens:

* AC66U itself has internet connection
* AC66U clients CANNOT ping 192.168.0.1. But they CAN ping 192.168.0.2 (AC66U)
* Clients connected to DLink directly do have internet access. They cannot ping AC66U when this happens.

The below graph illustrates the network and the intermittent problem:

Here's my LAN setup on AC66U:

To be fair, this problem occurs before I switched to the merlin firmware (it in fact was the reason for me to try out this firmware). I wonder if this is a hardware or firmware or software issue, or just simply that my setup is wrong. But I seem to remember to have this setup (AP mode) for more than a year and it just recently (past 2 months) when it started to occur.


I put on PasteBin some diagnostics I performed on AC66U through SSH. Look at here:

https://pastebin.com/raw/XjDwsgZk

 

[joegreat]

Anything in /tmp/syslog.log file of AC66U when the disconnects happen?

 

[KFL]

The syslog seems to be quiet. I'm having this issue right now and the last few lines of the log are:

Apr 3 10:26:23 rc_service: udhcpc_lan 1483:notify_rc start_dnsmasq
Apr 3 10:26:25 rc_service: udhcpc_lan 1483:notify_rc restart_dms
Apr 3 22:26:29 rc_service: udhcpc_lan 1733:notify_rc start_dnsmasq
Apr 3 22:26:31 rc_service: udhcpc_lan 1733:notify_rc restart_dms
Apr 4 16:26:36 rc_service: udhcpc_lan 2097:notify_rc start_dnsmasq
Apr 4 16:26:38 rc_service: udhcpc_lan 2097:notify_rc restart_dms
Apr 5 04:26:40 rc_service: udhcpc_lan 2477:notify_rc start_dnsmasq
Apr 5 04:26:42 rc_service: udhcpc_lan 2477:notify_rc restart_dms
Apr 5 09:09:41 dropbear[2581]: Child connection from 192.168.0.4:53719
Apr 5 09:09:48 dropbear[2582]: Child connection from 192.168.0.13:55051
Apr 5 09:09:51 dropbear[2582]: Password auth succeeded for 'admin' from 192.168.0.13:55051
Apr 5 09:10:02 dropbear[2581]: Exit before auth: Error reading: Connection reset by peer
Apr 5 09:16:42 dropbear[2582]: Exit (admin): Disconnect received
Apr 5 09:18:42 dropbear[2603]: Child connection from 192.168.0.20:54342
Apr 5 09:18:46 dropbear[2603]: Password auth succeeded for 'admin' from 192.168.0.20:54342

 

[sfx2000]

If you can - put the AP into a static address, not reserved by DHCP on the primary - ensure that address is outside of the DHCP scope of the primary...

that would be the first step...

 

[dlandiss]

Long shots: replace the Ethernet cable between the router and the access point. Try a different Ethernet socket at both ends.

 

[manwdaplan]

OK I am experiencing the same issue. But rebooting the access point does not fix the issue, the only fix is to reboot the router. The ASUS is a RT3200 device.
I am using the latest Merlin firmware (this was happening with a older version of the firmware as well from FEB). This just started happening to me a day ago (6/5/2017). I went ahead and factory reset the ASUS device and reset it up as a AP. The clients that are connected to it will get a address from the router, and I can see the devices on the network (pingable) they just can not get out to the internet. Once I reboot the router (which is a Cisco Router) it will work fine for a short time then stop working again. Oh and wired devices have no problem. Also to add a little bit of a monkey wrench to the whole thing, once wireless device (Kindle Fire) works fine. But two other android tablets don't work, my Samsung S8, Iphones and laptops dont work.

 

[manwdaplan]

OK I am experiencing the same issue. But rebooting the access point does not fix the issue, the only fix is to reboot the router. The ASUS is a RT3200 device.
I am using the latest Merlin firmware (this was happening with a older version of the firmware as well from FEB). This just started happening to me a day ago (6/5/2017). I went ahead and factory reset the ASUS device and reset it up as a AP. The clients that are connected to it will get a address from the router, and I can see the devices on the network (pingable) they just can not get out to the internet. Once I reboot the router (which is a Cisco Router) it will work fine for a short time then stop working again. Oh and wired devices have no problem. Also to add a little bit of a monkey wrench to the whole thing, once wireless device (Kindle Fire) works fine. But two other android tablets don't work, my Samsung S8, Iphones and laptops dont work.

To follow up with my own work, this ended up being the Kindle Fire's fault, I can not figure out why but as soon was I removed the device from the network this problem stopped happening. But I will be damned if I can tell you why, there where other Android tablets on the network not causing this issue

 

[Deleted member 22229]

If you can - put the AP into a static address, not reserved by DHCP on the primary - ensure that address is outside of the DHCP scope of the primary...

that would be the first step...

This is very good advice when using a router in AP mode.. ^