DrayTek UK Users' Community Forum

Help, Advice and Solutions from DrayTek Users

2762 Secondary DNS issue

  • xer0w
  • Topic Author
  • User
  • User
More
22 Mar 2019 20:07 #1 by xer0w
2762 Secondary DNS issue was created by xer0w
Hi,

I have my own local DNS server on my LAN that handles all DNS queries, so I have set its IP in LAN >> General Setup - Primary IP Address, and have left the Secondary IP Address BLANK.
This results in the router assigning the Primary IP correctly to clients, but it also sets the Secondary to the ISPs assigned DNS.

How do I stop the router assigning the ISP DNS when the secondary field is blank? (I have set the 'Force router to use "DNS server IP address" settings')
I only want a SINGLE DNS server ip assigned to my clients.

Firmware Version: 3.8.9.2_BT

Thanks in advance.

Please Log in or Create an account to join the conversation.

More
22 Mar 2019 20:41 #2 by x64
Replied by x64 on topic Re: 2762 Secondary DNS issue
I've seen similar issues on my 2862. My workaround was to put the same DNS server IP address in BOTH DNS server fields.

Please Log in or Create an account to join the conversation.

  • xer0w
  • Topic Author
  • User
  • User
More
22 Mar 2019 21:57 #3 by xer0w
Replied by xer0w on topic Re: 2762 Secondary DNS issue
Hi yes, I have tried that, but this causes 'DNS request timed out' issues (on Windows clients), which is suboptimal.

Please Log in or Create an account to join the conversation.

More
23 Mar 2019 10:47 #4 by x64
Replied by x64 on topic Re: 2762 Secondary DNS issue

xer0w wrote: Hi yes, I have tried that, but this causes 'DNS request timed out' issues (on Windows clients), which is suboptimal.


This configuration would not, by itself, cause Windows to suffer failed DNS requests. I'm sure that the cause of those failures lies in a misconfiguration elsewhere.

Do your Windows clients receive other DNS server addresses on other interfaces?

Also, this other 'local' DNS server that you have on you have... Can you tell us about that? I'm assuming that it handles some local names itself and either forwards requests for non-local names to your ISPs resolvers (or recurses for them from the root hints up). What is it? How do you have that configured?

Please Log in or Create an account to join the conversation.

  • xer0w
  • Topic Author
  • User
  • User
More
23 Mar 2019 13:43 #5 by xer0w
Replied by xer0w on topic Re: 2762 Secondary DNS issue

x64 wrote:
This configuration would not, by itself, cause Windows to suffer failed DNS requests. I'm sure that the cause of those failures lies in a misconfiguration elsewhere.

Do your Windows clients receive other DNS server addresses on other interfaces?

Also, this other 'local' DNS server that you have on you have... Can you tell us about that? I'm assuming that it handles some local names itself and either forwards requests for non-local names to your ISPs resolvers (or recurses for them from the root hints up). What is it? How do you have that configured?



Hi,

All Windows Clients I've tested have only a single interface, and show two DNS server IP's as assigned by the DrayTek
The DNS server is a pi-hole, and I've configured Conditional Forwarding to point to the DrayTek.
I suspect it might be related to reverse lookup forwarding, I'll do some more digging (pun intended :), although lookups don't time out if I manually set the Windows Client DNS server so it only has the single DNS entry (pointing to the pi-hole).

Thanks,

Please Log in or Create an account to join the conversation.

  • xer0w
  • Topic Author
  • User
  • User
More
14 Apr 2019 13:10 #6 by xer0w
Replied by xer0w on topic Re: 2762 Secondary DNS issue
Quick update, I figured out the issue, it was indeed my DNS server config, after enabling forwarding of non-FQDN and reverse lookup queries, everything works correctly now even with the same ip for both DNS servers in the DrayTek config.

Please Log in or Create an account to join the conversation.