Router DNS server not working

  • ATTENTION! As of November 1, 2020, you are not able to reply to threads 6 months after the thread is opened if there are more than 500 posts in the thread.
    Threads will not be locked, so posts may still be edited by their authors.
    Just start a new thread on the topic to post if you get an error message when trying to reply to a thread.

blava_b

Occasional Visitor
It appears that the built in DNS server on my router has stopped responding to queries. All my networking appears to be working fine and as long as I have DCHP configured to not use the router to resolve DNS everything works just fine. Any ideas on how to troubleshoot this?

1615219961114.png


I am running the current version of Asuswrt-Merlin.
1615220042486.png


Any help would be appreciated.

Thank you,
 

bbunge

Very Senior Member
What are your WAN/DNS Server settings? Are you using DoT/DNSSEC? Is LAN/DNS Filter turned on and if so to what?

Did the same test on my router and it works fine.
 
Last edited:

Mutzli

Very Senior Member
Try with DNS filter turned on and global filter pointing to router:
1615226078480.png
 

dave14305

Part of the Furniture
Try with DNS filter turned on and global filter pointing to router:
View attachment 31750
His screenshot shows that a LAN DHCP DNS server is set (based on the warning under DNS Privacy). So DNS Filter will force queries to the LAN DHCP DNS server instead of the router.
 

blava_b

Occasional Visitor
Thank you for the advice, but forcing DHCP to use the WAN DNS settings isn't going to solve my problem. I need to get DNS working properly on the router. As it is right now it won't respond to DNS queries over port 53 at all. I need to get DNS on the router working.
 

dave14305

Part of the Furniture
Running these commands on the router over SSH might help understand what's happening on the router end.
Code:
ps | grep dnsmasq
netstat -nltup | grep dnsmasq$
cat /etc/dnsmasq.conf
nslookup www.snbforums.com 127.0.0.1
 

blava_b

Occasional Visitor
I keep getting an error from the forums when I try to attach my dnsmasq.conf file or cut and paste it as text.

1615233247572.png
 

dave14305

Part of the Furniture
Which subnet is your Apollo machine on? You have 0, 2 and 5. Are you using the correct router address to reach the DNS server from the subnet? Are you running YazFi to customize your guest networks?
 

blava_b

Occasional Visitor
Which subnet is your Apollo machine on? You have 0, 2 and 5. Are you using the correct router address to reach the DNS server from the subnet? Are you running YazFi to customize your guest networks?
It's running on the .0 subnet. Yes YazFi was used to customize the guest networks.
 

blava_b

Occasional Visitor
FYI, just to eliminate something "odd" going on with my network switches, I've plugged my computer directly into a port on the router instead of one of the switches. Same results.

1615239344468.png


And just to confirm, you can see that Apollo is using the correct IP addresses for its subnet.

1615239401035.png
 

dave14305

Part of the Furniture
We need reinforcements. @Jack Yaz #notjacksfault
 
Last edited:

Jack Yaz

Part of the Furniture
where has add-mac and add-subnet come from? did you install NextDNS at any point?

also please post screenshots of LAN -> DNSFilter and output of iptables -S INPUT
 

Jack Yaz

Part of the Furniture
what are those rules for UDP port 53? I don't recognise them and they appear that they will block anything not matching that hex string, whatever it means
 

juched

Senior Member
what are those rules for UDP port 53? I don't recognise them and they appear that they will block anything not matching that hex string, whatever it means
Yup, that would appear to be it, as the next rule drops everything which goes to port 53 on br0.
 

Latest threads

Sign Up For SNBForums Daily Digest

Get an update of what's new every day delivered to your mailbox. Sign up here!
Top