No WAN/Internet on AC-68U all of a sudden

[tnkrer]

Hi
I have AC-68U with Asuswrt-merlin on it. This set up has worked for over a year. Had been very stable. In the year, it may have lost internet once or twice and power cycling modem/router would fix that problem

Yesterday evening, I lost internet.
* I power cycled, still no internet.
* I checked if I had internet on cable modem by directly taking the wire in my laptop. I had internet (and cable modem is showing all the right leds lit up). ISP is comcast.
* Then I left the power off on modem/router for 10 minutes, Restarted everything in order, still no internet.
* I updated firmware to latest, So now I have 380.66_4. That did not help.
* I tried modifying the setting to not take dhcp server from ISP, but use google dns (8.8.8.8, 8.8.4.4), Still no internet
* Then I reset the router to factory defaults and restarted everything, still no internet.
* I left the modem and router turned off overnight. Restarted everything in the morning, still no internet ...

I see that similar issues have been reported in this forum ..
RT-AC66U will not see WAN connection
Is this a bug on Asus firmware? WAN disconnections
But have not seen a concrete solution.

Is there a known solution to this problem? How should I debug this further? I do not have an older router at the moment to try and make that work. I am reading something about MAC and how ISP will honor a MAC and deny connections to other MAC .. but have not yet figured out if that is my issue or how to confirm/test that ..

Additional Clues:
Sometimes the router status says Connected to internet, but internet is not available. Sometimes, it says something about dhcp issues. In both cases, i do not actually have internet connection. When looking through logs, I saw this line at times
WAN Connection: ISP's DHCP did not function properly.
There was another line in log about either dhcp or ethernet .. Once I get back on the router, I will find it and post it
Once after power cycle I had internet connection for a few minutes and then it dropped out.
Any help is greatly appreciated .. If this does not work after a while, I am thinking of trying tomato/ddwrt and see if that will solve the problem. Will it or will that have the same issue?

 

[martinr]

Are you following this thread?

https://www.snbforums.com/threads/rt-ac66u-your-isps-dhcp-does-not-function-properly.35837/

On the surface, there are perhaps one or 2 similarities, but if nothing else it might spark some ideas. Switching to Tomato/ddwrt is a bit drastic and I really doubt that will fix your problem because it would suggest the problem lies in Merlin's firmware, and that's stretching the imagination too far. Your time would be better spent in troubleshooting rather that in making extra work for yourself which is unlikely to fix the problem and more likely to introduce additional ones.

 

[tnkrer]

Thanks, I am following that thread and have a post at the end of that thread asking its OP how s/he solved the problem

changing firmware does seem drastic, but gotta have internet for multiple people at home and I don't have any more things to try ..

At the moment the router says it is connected to internet, there are no errors in logs and yet there is no internet connection, pinging opendns server results in
PS [C:\Users\tnkrer] (57)> ping 208.67.222.222

Pinging 208.67.222.222 with 32 bytes of data:
Request timed out.
Reply from 24.60.112.8: Destination host unreachable.

Ping statistics for 208.67.222.222:
Packets: Sent = 2, Received = 1, Lost = 1 (50% loss),

24.60.112.8 was my IP address at that time. After I shut down the modem for longer time, it does change and router does see it and gets it .. so that part is working. However, after that I cannot reach any outside address

 

[john9527]

Where are you located?

 

[john9527]

It may be luck of the draw that when you connect a PC directly, you are getting an IP address that is working. Try cloning your PC's mac to the router on the WAN page.

 

[sfx2000]

Hi
I have AC-68U with Asuswrt-merlin on it. This set up has worked for over a year. Had been very stable. In the year, it may have lost internet once or twice and power cycling modem/router would fix that problem

Yesterday evening, I lost internet.
* I power cycled, still no internet.
* I checked if I had internet on cable modem by directly taking the wire in my laptop. I had internet (and cable modem is showing all the right leds lit up). ISP is comcast.
* Then I left the power off on modem/router for 10 minutes, Restarted everything in order, still no internet.
* I updated firmware to latest, So now I have 380.66_4. That did not help.
* I tried modifying the setting to not take dhcp server from ISP, but use google dns (8.8.8.8, 8.8.4.4), Still no internet
* Then I reset the router to factory defaults and restarted everything, still no internet.
* I left the modem and router turned off overnight. Restarted everything in the morning, still no internet ...

Sounds like an outage at the ISP - nothing you can do there...

Outages happen - middle of the night, someone drunk fires up a backhoe - what's this?

 

[tnkrer]

During my testing, I connected by cable directly to cable modem three times, and all three times I had internet. So I am going to assume that there was no outage. Low probability of internet just showing up exactly when I was on cable modem directly and not showing up when I was on router during the last 24 hours.
I did install tomato and internet has started working. (posting this with tomato)
I still want to figure out the problem and may want to go back to merlin .. will see how tomato works out for next few days

@john, I did copy laptop's mac id on merlin WAN setup. and that cleared the dhcp errors and merlin network map page did show that I was connected with the right IP address and everything and yet I did not get internet

 

[tnkrer]

So that does not seem to be the correct reason why tomato is working.
During tomato install, I had removed all the cat cables from the router ports 2-4. Port 1 was used for tomato install. After tomato started working and I put back those cat cables in ports 1-4, no internet again! When I took those wires out from ports 1-4 I am getting internet. So it is quite possible that I would have gotten internet on wireless if I had removed the wires from port 1-4 while on asus merlin ..
So what's up with this? Why are those wired ports killing me? One of those cables goes to 5 port unmanaged switch.. Would that cause a problem?

 

[john9527]

Go one at a time connecting the ports until you find the offending client. If it looks like there isn't a single one causing it, most likely your power supply has given up and is 'drooping' under load.

 

[sfx2000]

most likely your power supply has given up and is 'drooping' under load.

Random outages on the WAN side do happen - but they're not common - so the ac adapter is a good area to look at...

 

[tnkrer]

Changed the network switch with my older 100 mbps switch (which was connected to one of the ports on the router) and that is not causing WAN disconnects. I may debug this further (or may not). At the moment, I am trying to figure out how to get back to Asus-merlin.

 

[Vexira]

is your modem set to bridge mode, i had an issue where i lost net connection on my 88u cause my vdsl2 modem bugged out, and bridge mode disabled itself.