RT-AC68U Stopped responding to DNS requests (Resolved 11/17/2017)

[z3r0k3wl]

For some odd reason, my router no longer responds to DNS requests. None of a variety of clients have internet access anymore. I've done a factory reset, reflash both stock and Merlin firmware, cleared nvram etc but for the life of me DNS no longer works. Also, when I go through the Quick Internet Wizard, it skips Step 2 which is the Internet setup. I have other spare routers on hand so I tested them and they're working fine.

Is my RT-AC68U router FUBAR?

 

[appleseed]

This may not apply to you but Level 3 (internet backbone) had massive problems 24hrs ago and still recovering (https://www.wired.com/story/how-a-tiny-error-shut-off-the-internet-for-parts-of-the-us/). I had similar DNS problems you describe, but better now. I have the same router, so not sure if yours is bad, but more info may be helpful. What about local DNS within your home subnet - does it work?

 

[z3r0k3wl]

This may not apply to you but Level 3 (internet backbone) had massive problems 24hrs ago and still recovering (https://www.wired.com/story/how-a-tiny-error-shut-off-the-internet-for-parts-of-the-us/). I had similar DNS problems you describe, but better now. I have the same router, so not sure if yours is bad, but more info may be helpful. What about local DNS within your home subnet - does it work?

By local do you mean my ISP's DNS? It works fine. I have also set it to google's public DNS and still doesn't work. DHCP is sending the ip configuration to my devices, and it shows 8.8.8.8 as primary DNS, but any DN queries is not passing along to public DNS. What other info would you like?

 

[ColinTaylor]

From a client on your LAN what do the following 2 commands return?

C:\Users\Colin>ping 8.8.8.8

Pinging 8.8.8.8 with 32 bytes of data:
Reply from 8.8.8.8: bytes=32 time=18ms TTL=55
Reply from 8.8.8.8: bytes=32 time=18ms TTL=55
Reply from 8.8.8.8: bytes=32 time=17ms TTL=55
Reply from 8.8.8.8: bytes=32 time=17ms TTL=55

Ping statistics for 8.8.8.8:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 17ms, Maximum = 18ms, Average = 17ms

C:\Users\Colin>nslookup www.google.com 8.8.8.8
Server:  google-public-dns-a.google.com
Address:  8.8.8.8

Non-authoritative answer:
Name:    www.google.com
Addresses:  2a00:1450:4009:80b::2004
          216.58.201.36

 

[z3r0k3wl]

From a client on your LAN what do the following 2 commands return?

C:\Users\Colin>ping 8.8.8.8

Pinging 8.8.8.8 with 32 bytes of data:
Reply from 8.8.8.8: bytes=32 time=18ms TTL=55
Reply from 8.8.8.8: bytes=32 time=18ms TTL=55
Reply from 8.8.8.8: bytes=32 time=17ms TTL=55
Reply from 8.8.8.8: bytes=32 time=17ms TTL=55

Ping statistics for 8.8.8.8:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 17ms, Maximum = 18ms, Average = 17ms

C:\Users\Colin>nslookup www.google.com 8.8.8.8
Server:  google-public-dns-a.google.com
Address:  8.8.8.8

Non-authoritative answer:
Name:    www.google.com
Addresses:  2a00:1450:4009:80b::2004
          216.58.201.36

Absolutely nothing. Pinging and nslookup return nothing using Asus router. Using my spare D-Link I get the expected respond to as you posted.

 

[ColinTaylor]

Can you post the output so we can see the error message. Also post the output of ipconfig

 

[z3r0k3wl]

Can you post the output so we can see the error message. Also post the output of ipconfig

I'll have to share the info later as I can't take down the net with Plex users on.

 

[walttheboss]

Very similar issues on my N66. Latest version or versions did something very strange. Looking forward to what you all discover.

 

[FCM]

I believe I have also encountered this or a similar issue: out of the blue, some sites would not work if coming from redirect links. If i entered the web address by hand, they would. Resetting the router would fix it for a while, then the issue would reappear. I've temporary switched to the latest official Asus firmware and the issue has gone away.

One fix also worked for a while was to change the ip of the default gateway in the router interface and then change it back to the initial value (in the dhcp page). This would reset connections and was faster than a full router reboot.

 

[z3r0k3wl]

One fix also worked for a while was to change the ip of the default gateway in the router interface and then change it back to the initial value (in the dhcp page). This would reset connections and was faster than a full router reboot.

Tried this but did not resolve the resolve the problem

Can you post the output so we can see the error message. Also post the output of ipconfig

Whether I set the WAN DSN or not this is the results of ping and nslookup.

PING:
Pinging 8.8.8.8 with 32 bytes of data:
Request timed out.
Request timed out.
Request timed out.
Request timed out.

Ping statistics for 8.8.8.8:
Packets: Sent = 4, Received = 0, Lost = 4 (100% loss),

NSLOOKUP:
C:\Windows\system32>nslookup 8.8.8.8
Server: THEGIBSON
Address: 192.168.1.1

DNS request timed out.
timeout was 2 seconds.
*** Request to THEGIBSON timed-out

IPCONFIG /ALL:
Ethernet adapter Ethernet:

Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Intel(R) 82579V Gigabit Network Connection
Physical Address. . . . . . . . . : 14-DA-E9-13-8D-8B
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Link-local IPv6 Address . . . . . : fe80::688f:6e65:5ad1:6f3f%3(Preferred)
IPv4 Address. . . . . . . . . . . : 192.168.1.100(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Lease Obtained. . . . . . . . . . : Thursday, November 9, 2017 8:50:11 AM
Lease Expires . . . . . . . . . . : Friday, November 10, 2017 8:50:10 AM
Default Gateway . . . . . . . . . : 192.168.1.1
DHCP Server . . . . . . . . . . . : 192.168.1.1
DHCPv6 IAID . . . . . . . . . . . : 202693353
DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-21-90-18-6B-14-DA-E9-13-8D-8B
DNS Servers . . . . . . . . . . . : 192.168.1.1
NetBIOS over Tcpip. . . . . . . . : Enabled

When I define DHCP DNS

PING:
Pinging 8.8.8.8 with 32 bytes of data:
Request timed out.
Request timed out.
Request timed out.
Request timed out.

Ping statistics for 8.8.8.8:
Packets: Sent = 4, Received = 0, Lost = 4 (100% loss),

NSLOOKUP:
C:\Windows\system32>nslookup 8.8.8.8
DNS request timed out.
timeout was 2 seconds.
Server: UnKnown
Address: 8.8.8.8

DNS request timed out.
timeout was 2 seconds.
*** Request to UnKnown timed-out

IPCONFIG /ALL:
Ethernet adapter Ethernet:

Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Intel(R) 82579V Gigabit Network Connection
Physical Address. . . . . . . . . : 14-DA-E9-13-8D-8B
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Link-local IPv6 Address . . . . . : fe80::688f:6e65:5ad1:6f3f%3(Preferred)
IPv4 Address. . . . . . . . . . . : 192.168.1.100(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Lease Obtained. . . . . . . . . . : Thursday, November 9, 2017 1:45:39 PM
Lease Expires . . . . . . . . . . : Friday, November 10, 2017 1:45:38 PM
Default Gateway . . . . . . . . . : 192.168.1.1
DHCP Server . . . . . . . . . . . : 192.168.1.1
DHCPv6 IAID . . . . . . . . . . . : 202693353
DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-21-90-18-6B-14-DA-E9-13-8D-8B
DNS Servers . . . . . . . . . . . : 8.8.8.8
8.8.4.4
192.168.1.1
NetBIOS over Tcpip. . . . . . . . : Enabled

With another router (D-Link), it works fine. Just the Asus RT-AC68U. It has the latest prod firmware.

PING:
C:\Windows\system32>ping 8.8.8.8

Pinging 8.8.8.8 with 32 bytes of data:
Reply from 8.8.8.8: bytes=32 time=23ms TTL=59
Reply from 8.8.8.8: bytes=32 time=20ms TTL=59
Reply from 8.8.8.8: bytes=32 time=21ms TTL=59
Reply from 8.8.8.8: bytes=32 time=29ms TTL=59

Ping statistics for 8.8.8.8:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 20ms, Maximum = 29ms, Average = 23ms

NSLOOKUP:
C:\Windows\system32>nslookup /all
Server: router.dlink.com
Address: 192.168.1.1

*** router.dlink.com can't find /all: Non-existent domain

C:\Windows\system32>nslookup 8.8.8.8
Server: router.dlink.com
Address: 192.168.1.1

Name: google-public-dns-a.google.com
Address: 8.8.8.8

IPCONFIG /ALL:
C:\Windows\system32>ipconfig /all

Ethernet adapter Ethernet:

Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Intel(R) 82579V Gigabit Network Connection
Physical Address. . . . . . . . . : 14-DA-E9-13-8D-8B
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Link-local IPv6 Address . . . . . : fe80::688f:6e65:5ad1:6f3f%3(Preferred)
IPv4 Address. . . . . . . . . . . : 192.168.1.100(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Lease Obtained. . . . . . . . . . : Thursday, November 9, 2017 2:22:56 PM
Lease Expires . . . . . . . . . . : Friday, November 10, 2017 2:22:56 PM
Default Gateway . . . . . . . . . : 192.168.1.1
DHCP Server . . . . . . . . . . . : 192.168.1.1
DHCPv6 IAID . . . . . . . . . . . : 202693353
DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-21-90-18-6B-14-DA-E9-13-8D-8B
DNS Servers . . . . . . . . . . . : 192.168.1.1
NetBIOS over Tcpip. . . . . . . . : Enabled

 

[ColinTaylor]

Your issue doesn't appear to be anything to do with DNS but rather a complete lack of connectivity to the internet.

In the router's web interface what does it say at Network Map > Internet status (the globe at the top of the page)?

 

[z3r0k3wl]

Your issue doesn't appear to be anything to do with DNS but rather a complete lack of connectivity to the internet.

In the router's web interface what does it say at Network Map > Internet status (the globe at the top of the page)?

Says Connected.

 

[ColinTaylor]

You said in your original post that the router skipped the internet setup stage. Can you confirm that your router (Administration - Operation Mode) is in "Wireless router mode (Default)" and not one of the other modes.

Also, go to Network Tools > Network Analysis and see if you can ping google.com from there.

 

[z3r0k3wl]

You said in your original post that the router skipped the internet setup stage. Can you confirm that your router (Administration - Operation Mode) is in "Wireless router mode (Default)" and not one of the other modes.

Also, go to Network Tools > Network Analysis and see if you can ping google.com from there.

It is in Wireless router mode (Default). Router is also getting a WAN IP.

Edit:. Forgot to answer your second request. I tried and ping failed.

 

[z3r0k3wl]

I was able to resolve the issue buy switching operation mode to Repeater then back again to Wireless router.