Trouble resolving att.com

[Ichinisan]

Any idea what's going on with att.com or Google's free DNS?

Asus RT-AC68U router.

I can't resolve att.com from my ISP DNS, nor from Google's 8.8.8.8

Rebooting the router did not help.

I changed DNS to 4.2.2.2 and I can resolve att.com now, so I can finally load the web page.

 

[mxnerd]

Fine from here.

C:\Windows\System32>nslookup
Default Server: google-public-dns-b.google.com
Address: 8.8.4.4

> server 8.8.8.8
Default Server: google-public-dns-a.google.com
Address: 8.8.8.8

> att.com
Server: google-public-dns-a.google.com
Address: 8.8.8.8

Non-authoritative answer:
Name: att.com
Addresses: 2001:1890:1c00:5112::f:1008
2001:1890:1c00:3113::f:3005
144.160.155.43
144.160.36.42

> server 4.2.2.2
Default Server: b.resolvers.Level3.net
Address: 4.2.2.2

> att.com
Server: b.resolvers.Level3.net
Address: 4.2.2.2

Non-authoritative answer:
Name: att.com
Addresses: 2001:1890:1c00:3113::f:3005
2001:1890:1c00:5112::f:1008
144.160.155.43
144.160.36.42

=====================

Enter you ISP's DNS ip address into nslookup's server command and see if it returns att.com ip address.

 

[sdifox]

I have no issues resolving

 

[Ichinisan]

Fine from here.

C:\Windows\System32>nslookup
Default Server: google-public-dns-b.google.com
Address: 8.8.4.4

> server 8.8.8.8
Default Server: google-public-dns-a.google.com
Address: 8.8.8.8

> att.com
Server: google-public-dns-a.google.com
Address: 8.8.8.8

Non-authoritative answer:
Name: att.com
Addresses: 2001:1890:1c00:5112::f:1008
2001:1890:1c00:3113::f:3005
144.160.155.43
144.160.36.42

> server 4.2.2.2
Default Server: b.resolvers.Level3.net
Address: 4.2.2.2

> att.com
Server: b.resolvers.Level3.net
Address: 4.2.2.2

Non-authoritative answer:
Name: att.com
Addresses: 2001:1890:1c00:3113::f:3005
2001:1890:1c00:5112::f:1008
144.160.155.43
144.160.36.42

=====================

Enter you ISP's DNS ip address into nslookup's server command and see if it returns att.com ip address.

I used nslookup to determine that it seems to be Google's DNS acting up.

Fail:
nslookup att.com 8.8.8.8
nslookup att.com [ISP's old DNS server address]

Success:
nslookup att.com 4.2.2.2
nslookup google.com 8.8.8.8
nslookup google.com 4.2.2.2
nslookup google.com [ISP's old DNS server address]

I cycled through each test multiple times before and after rebooting my Asus RT-AC68U router.

I believe my ISP still pushes 8.8.8.8 and 8.8.4.4 (Google) via DHCP for DNS, but I cannot find any sort of WAN/DHCP status screen in my router's web based setup. I have the latest official firmware (not custom or Merlin or whatever).

The only thing that worked was setting manual DNS in my router to 4.2.2.2

Anyway, all the above tests work now so the problem has cleared and I should be able to configure my router back to automatic DHCP.

Does anyone know how to make an Asus RT-AC68U reveal WAN DHCP info?

 

[boomerang]

What browser are you using? Edge has DNS problems related to the creator's update.

We got fiber last week and suddenly I can't get web pages to load. I initially figured it was the new ISP and had to find a tutorial on setting up my Edgerouter to use different DNS servers. With that done, the problem still existed. I then did some searching and found out the problem was actually with Edge. I went back to FF and all is well.

 

[Ichinisan]

What browser are you using? Edge has DNS problems related to the creator's update.

We got fiber last week and suddenly I can't get web pages to load. I initially figured it was the new ISP and had to find a tutorial on setting up my Edgerouter to use different DNS servers. With that done, the problem still existed. I then did some searching and found out the problem was actually with Edge. I went back to FF and all is well.

Chrome, but I ruled that out since I had used nslookup from command line before I finally set manual DNS 4.2.2.2 in my router settings.

 

[mxnerd]

Clear DNS cache and see

IPConfig /flushdns

 

[razel]

You may also want to dig into your network settings in windows to see if you have specified any DNS servers there. Additionally check your lmhosts file. If still the same, run that old hijackthis tool. It easily lists out the common known DNS override locations.

 

[Ichinisan]

You may also want to dig into your network settings in windows to see if you have specified any DNS servers there. Additionally check your lmhosts file. If still the same, run that old hijackthis tool. It easily lists out the common known DNS override locations.

ipconfig /all reports my router's private internal IP, and having manual DNS shouldn't affect the NSLOOKUP tests I ran.

I dunno. Maybe my ISP was specifically interfering with DNS somehow. All is back to normal now.

 

[sdifox]

ipconfig /all reports my router's private internal IP, and having manual DNS shouldn't affect the NSLOOKUP tests I ran.

I dunno. Maybe my ISP was specifically interfering with DNS somehow. All is back to normal now.

Err what do you think specifying the dns server in your ipconfig does?

 

[Ichinisan]

Err what do you think specifying the dns server in your ipconfig does?

The nslookup commands I typed above specify the DNS server IP address to use for each lookup, so manual DNS entered in Windows would have no effect.

This:

I used nslookup to determine that it seems to be Google's DNS acting up.

Fail:
nslookup att.com 8.8.8.8
nslookup att.com [ISP's old DNS server address]

Success:
nslookup att.com 4.2.2.2
nslookup google.com 8.8.8.8
nslookup google.com 4.2.2.2
nslookup google.com [ISP's old DNS server address]

I cycled through each test multiple times before and after rebooting my Asus RT-AC68U router.

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