AC66U WAN Disconnection Problems after upgrade (and subsequent downgrade!!)

[jamesp]

I mistakenly updated my ASUS RT-AC66U router to the latest buggy firmware (3.0.0.4.380.3264).
This caused the router to lose internet connectivity at regular intervals.
At certain times it appeared to be doing this reliably every 35 minutes.

I managed to put the router in rescue mode and downgraded the firmware to the version it was on prior to the upgrade (3.0.0.4.378.9533). I also performed a factory reset after installation. But, strangely enough the problem seemed to remain. The WAN was shutting down every 35 minutes.

Again I put the router in rescue mode and installed the latest Merlin firmware (380.59_0).
This is what I have currently installed, but the problem still persists.

This issue didn't exist before I updated to the latest ASUS firmware.

Can someone please help me get this sorted. It's driving me mad.
I work from home and this is causing me real problems.
I don't want to dump the router just because of a lousy firmware upgrade.

I've attached the latest system log.
It clearly shows the WAN disconnections.
The last disconnection being on 'Jun 7 09:31:44' and the previous disconnection ending on 'Jun 7 08:56:44'.

 

[RMerlin]

Jun  7 01:07:54 WAN Connection: Ethernet link down.

Your modem is rebooting, indicating a problem with either your modem or your ISP.

 

[L&LD]

Your attached file is headache inducing.

Have you tried turning off all network equipment for at least 30 minutes to an hour (physically unplugging each one from the wall AC) and then booting them up in the following order, waiting 5 minutes in between each?

Turn on modem (wait 5 minutes).

Turn on router (wait 5 minutes).

Turn on any switches you may be using.

Turn on your wired computers.

Turn on your wireless devices.

 

[jamesp]

I'll try what you suggest later this evening and report back to you.

Aside from using the web interface to restore factory settings, is there any other way to reliably clear all settings and configurations?
I'm not sure if the web interface does a complete job as I still appear to have names assigned to some of my MAC addresses.

 

[jamesp]

Jun  7 01:07:54 WAN Connection: Ethernet link down.

Your modem is rebooting, indicating a problem with either your modem or your ISP.

It can't be rebooting because the LAN doesn't go down. The kids can still watch their movies on the home network with any disruption.

 

[RMerlin]

It can't be rebooting because the LAN doesn't go down. The kids can still watch their movies on the home network with any disruption.

I said your modem, not your router... The router reported that the Ethernet connection on the WAN port went down.

 

[mstombs]

The repeated 36 minute drop is a common reported fault with the UK Virginmedia SH3 superhub in modem mode. This is an Arris cable device with 16 downstreams, seems to work with Cisco upstream devices but not Arris, for some users.

Some good analysis in this ISP support forum thread http://community.virginmedia.com/t5/Networking-and-wireless/Hub-3-0-port-flapping/m-p/3073985 but no solution apart from persuading them to revert to an older device.

Some claims it is due to dhcp messages, but seems to be modem firmware not router issue.

 

[jamesp]

I said your modem, not your router... The router reported that the Ethernet connection on the WAN port went down.

Yes you did. My apologies...

 

[jamesp]

The repeated 36 minute drop is a common reported fault with the UK Virginmedia SH3 superhub in modem mode. This is an Arris cable device with 16 downstreams, seems to work with Cisco upstream devices but not Arris, for some users.

Some good analysis in this ISP support forum thread http://community.virginmedia.com/t5/Networking-and-wireless/Hub-3-0-port-flapping/m-p/3073985 but no solution apart from persuading them to revert to an older device.

Some claims it is due to dhcp messages, but seems to be modem firmware not router issue.

Bingo!! That's exactly what I have, a Virginmedia SH3 superhub. And its in modem mode...

I'll look in to this further...

Thanks!

 

[jamesp]

OK, I may have fixed it....
The WAN has been running for 12 hours now without a problem.

Firstly, my modem is not a Virgin Media SH3 Superhub as I previously mentioned, its the Hub 3.0.

L&LD, I did mostly what you suggested.
I also reset and upgraded the router firmware before reconnecting the modem.

These are the steps I performed. Some of them may be a little paranoid, but it’s what I did and appears to have worked, for the time being at least.

1. Turn off Modem and remove power supply
2. Turn off Router and remove power supply
3. Disconnect Modem from Router
4. Leave everything for 5 minutes

5. Turn on Modem

6. Turn on Router
7. Factory reset Router from Web-GUI
8. Reboot Router manually

9. Reinstall Router firmware (Merlin 380.59_0)
10. Factory reset Router from Web-GUI
11. Reboot Router manually
12. Manually re-configure Router and wireless networks

The Modem should be up and running for about 15 minutes at this point

13. Reconnect Modem to Router

That’s it!
Log-in to the AC66U web-GUI and keep an eye on the system log...


I’ll give update in a few days....

 

[mstombs]

Firstly, my modem is not a Virgin Media SH3 Superhub as I previously mentioned, its the Hub 3.0.

Sorry, same thing I am sure, previous devices were Netgear kit SH2 and SH2AC, this is Arris

Fingers crossed for you, but just turning it off and on again fixes the problem for a short time for some...

 

[jamesp]

Yeah that's mine!

On the Virgin website I can choose from 4 modems.

I thought you were referring to the Super Hub below

Yep fingers crossed.

I'll report back in a couple of days.

 

[L&LD]

OK, I may have fixed it....
The WAN has been running for 12 hours now without a problem.

Firstly, my modem is not a Virgin Media SH3 Superhub as I previously mentioned, its the Hub 3.0.

L&LD, I did mostly what you suggested.
I also reset and upgraded the router firmware before reconnecting the modem.

These are the steps I performed. Some of them may be a little paranoid, but it’s what I did and appears to have worked, for the time being at least.

1. Turn off Modem and remove power supply
2. Turn off Router and remove power supply
3. Disconnect Modem from Router
4. Leave everything for 5 minutes

5. Turn on Modem

6. Turn on Router
7. Factory reset Router from Web-GUI
8. Reboot Router manually
9. Reinstall Router firmware (Merlin 380.59_0)
10. Factory reset Router from Web-GUI
11. Reboot Router manually
12. Manually re-configure Router and wireless networks

The Modem should be up and running for about 15 minutes at this point

13. Reconnect Modem to Router

That’s it!
Log-in to the AC66U web-GUI and keep an eye on the system log...


I’ll give update in a few days....

As long as it works, great! Hope to see your update as a 'still works'! kind of post.

 

[jamesp]

Still working!!

It's been over 2 days now and WAN connectivity has been stable.
No dropouts!

Cautiously, I'd like to say the problem has been resolved.....

 

[jamesp]

After 10 days the problem has returned!!

Will have to switch back to router mode as it appears there is no other solution at the moment....

 

[mstombs]

I also had the problem yesterday, just turning the VM SH3 modem off for a couple of minutes then turning back on again fixed it for me. I understand a cable modem firmware fix is being investigated, but I wonder if if it is a hardware chipset issue they are trying to workaround.