On my network I have a Barracuda 310 web filter installed. After an issue with our ISP suddenly interrupting our DNS service, we switched over to a more reliable DNS on all of our systems.
Unfortunately, after a ton of research a few boxes continued to be afflicted by this. The culprit? It appears the Barracuda filter we have is serving cached pages that still show the "your DNS isn't properly configured" error message. I can't seem to get them to clear out of the system by clearing the content cache, or changing the DNS associated with the barracuda unit itself. I've ran a NSLOOKUP on the device itself, and it appears its DNS cache is still fixed to the old data.
Compounding the problem, our subscription has expired for this unit. Personally, I do not want to give them money to tell me how to solve such a simple problem, and the techs are stonewalling me until I pay.
Does anyone know how clear the DNS cache and any cached pages from a Barracuda 310? Thanks!
EDIT: For people looking for the solution, I simply fired up expert mode and disabled "Use the DNS cache service to handle heavy DNS traffic loads." It immediately started working afterwords.
Best Answer
I don't have access to a Barracuda web filter, but the email appliance has a hidden "Expert Options" menu that you can access that may contain some additional settings. Login to the device, click the "Advanced" tab, and then add "&expert=1" to the end of the URL to access the hidden menu; my URL looked like this after the change:
https://ipaddress/cgi-mod/index.cgi?&user=username&password=hash&et=1419376946&auth_type=Local&locale=en_US&primary_tab=ADVANCED&expert=1Hope this helps!