OPNsense Forum

Archive => 18.1 Legacy Series => Topic started by: maxxer on July 19, 2018, 12:29:37 pm

Title: Intermittent DNS resolution problems
Post by: maxxer on July 19, 2018, 12:29:37 pm
I've setup a new system with 18.1.12. We have 3 WANs, set up following the guide (https://docs.opnsense.org/manual/how-tos/multiwan.html) on the docs.  I've also enabled Unbuond DNS resolver to provider better DNS to the LAN.

Unfortunately sometimes the DNS is not responding, and so far I was unable to track down the problem and understand where it comes from.

As per the guide I've set up a DNS for every WAN (google and opendns), and if I go to Interfaces > Diagnostic > DNS lookup it always work fast (even for But if from the PC where I perform the test via web I try a dig it returns timeout! I repeat the dig command for two or three times always returing timeout! Then, suddendly, I run dig once more and it returns immediately the result.

I've configured the firewall DNS rule (chapter 5 of the guide above), even if I don't exactly understand why it's needed: if the DNS IP is the firewall address, why should a LAN connection use the gateway?

Any hint on how to debug the problem  is very welcome. thanks