No internet connection on my PCs, although the router appears to be connected.

[M1k1]

Last week one of the PC connected to my newly bought AC68U router (with hw rev E1, and stock fw 3.0.0.4.380_3264) lost the internet connection (the network icon at the bottom right of the taskbar showed an yellow exclamation mark). I logged into the AsusWRT and there I saw that the router was connected to the internet (WAN) and starting-up the other PC I had as well internet connection.
Diagnosing the disconnected PC showed up that there was a problem with the DNS. Then I looked at the DNS settings form the IPv4 and I saw some strange IPs there (that were definitely not of my ISP). I changed the option to obtain the DNS server address automatically, but still no internet connection.
Then I remembered that I put the Google DNS server addresses in the router settings. I changed this option back to Connect to DNS Server automatically and finally I had internet connection again on all of my PCs.
Did anyone experienced this problem before on an Asus router? It is a known bug or it might have been a malware that changed the PC's DNS addresses?

 

[wouterv]

I guess a glitch in Google DNS, all the rest seems quite obvious and not related to your router or PC other then faulty or non functional DNS settings.

 

[M1k1]

Unfortunately the problem keeps occurring. And actually, there is no internet connection on both of my PCs, although the router appears to be connected to the internet. I don't line this at all. I paid quite a lot for this router and I don't want to reboot it over and over. I'm seriously thinking of return it.

 

[Odkrys]

do test without a router.
Connect to modem directly and do ipconfig /flushdns on cmd.
If you can't get internet again, it is your PC problem. then run anti-virus.

 

[M1k1]

do test without a router.
Connect to modem directly and do ipconfig /flushdns on cmd.
If you can't get internet again, it is your PC problem. then run anti-virus.

I had two routers before and this problem never occurred. I don't have a modem anyhow as there is only an UTP cable connecting directly to the ISP.

 

[Wutikorn]

Have you tried upgrading firmware to 3.0.0.4.380.3831? Is there 3.0.0.4.380.3831 for your revision? I remember that .3264, comparable to AsusWRT-Merlin 380.60, has tons of WAN problem even in RMerlin's firmware. That is why there is no stable version of 380.60(due to WAN connection problem). WAN problem was terrible for me at the time as well, so my first suggestion would be to upgrade firmware to .3831 if your router is supported.

 

[blades]

Last week one of the PC connected to my newly bought AC68U router (with hw rev E1, and stock fw 3.0.0.4.380_3264) lost the internet connection (the network icon at the bottom right of the taskbar showed an yellow exclamation mark). I logged into the AsusWRT and there I saw that the router was connected to the internet (WAN) and starting-up the other PC I had as well internet connection.
Diagnosing the disconnected PC showed up that there was a problem with the DNS. Then I looked at the DNS settings form the IPv4 and I saw some strange IPs there (that were definitely not of my ISP). I changed the option to obtain the DNS server address automatically, but still no internet connection.
Then I remembered that I put the Google DNS server addresses in the router settings. I changed this option back to Connect to DNS Server automatically and finally I had internet connection again on all of my PCs.
Did anyone experienced this problem before on an Asus router? It is a known bug or it might have been a malware that changed the PC's DNS addresses?

Make a live usb with Ubuntu 16.04, try without installing and see how it goes.

 

[M1k1]

Have you tried upgrading firmware to 3.0.0.4.380.3831? Is there 3.0.0.4.380.3831 for your revision? I remember that .3264, comparable to AsusWRT-Merlin 380.60, has tons of WAN problem even in RMerlin's firmware. That is why there is no stable version of 380.60(due to WAN connection problem). WAN problem was terrible for me at the time as well, so my first suggestion would be to upgrade firmware to .3831 if your router is supported.

Thank you for you advice. I just upgraded the firmware to the latest available one. Now I have the version 3.0.0.4.380.4118. Let's see how it behaves.

 

[Wutikorn]

Thank you for you advice. I just upgraded the firmware to the latest available one. Now I have the version 3.0.0.4.380.4118. Let's see how it behaves.

Where did you download that firmware? Can you give me a link(just curious)? Is it specifically for rev E1? I hope it works out for you.

 

[M1k1]

Where did you download that firmware? Can you give me a link(just curious)? Is it specifically for rev E1? I hope it works out for you.

I just downloaded it through the router's UI. I know that on the Asus official download page this version is not listed yet (the latest version there is 3.0.0.4.380.3831).

 

[Super Bee]

DNS reliability is extremely important, since lookup requests that are dropped and ignored by nameservers cause significant delays in Internet access while the querying system waits for a reply. The system is then finally forced to reissue the query to the same or to backup nameservers. While your system is patiently waiting for a reply, you are impatiently waiting to get on with your Internet access.

Have you tried other DNS servers besides Google's? I always use GRC's DNS Benchmark to find the fastest DNS servers.

 

[M1k1]

Have you tried other DNS servers besides Google's? I always use GRC's DNS Benchmark to find the fastest DNS servers.

Thank you Super Bee. I did that already. The most reliable DNS servers, besides my IPS ones, are the ones from Google (8.8.8.8 & 8.8.4.4).

 

[Wutikorn]

I think there are some malwares that can change your DNS setting. You should probably run Anti-Virus(Avast Free probably, or try Sophos Home) and then run Malwarebytes, free version(no real time protection) as it normally finds what Anti-Virus won't. If you are going to Asus Merlin soon, you can check out DNS Filtering option which will block connectionห if your PCs are not using DNS servers you set, so you know if something is changing your PC's DNS setting.

 

[M1k1]

I was suspecting that too Wutikorn, but so far I found no malware.

On the other hand I think I found a bug either in Firefox or in AsusWRT: I closed by mistake the tab with the AsusWRT then I opened a new tab and typing the secure Web page address (https://192.168.1.1:8443/) I was back into the GUI without being asked to enter my credentials, which shouldn't happen (in Chrome if I do the same thing I'm always asked for the credentials). Did someone encountered this problem? Or is just my Firefox broken or something?

 

[Wutikorn]

I was suspecting that too Wutikorn, but so far I found no malware.

Have you used Malwarebytes too?

On the other hand I think I found a bug either in Firefox or in AsusWRT: I closed by mistake the tab with the AsusWRT then I opened a new tab and typing the secure Web page address (https://192.168.1.1:8443/) I was back into the GUI without being asked to enter my credentials, which shouldn't happen (in Chrome if I do the same thing I'm always asked for the credentials). Did someone encountered this problem? Or is just my Firefox broken or something?

When I was logged in to secure GUI in latest Chrome 64bit, I closed the GUI, and reopened it, it didn't ask for my credentials either. I thought it does not log you out until Auto Logout time is reached or several minutes after closing GUI, but I'm not sure if it should automatically log you out if you close a tab or not.