Our ISP changed their DNS records in the router we use with without us knowing and we were unable to reach the Internet. When we contacted them, they stated that we should have been informed a month before through email which we never were. We changed our SonicWall to match the new DNS records but we were still unable to consistently go o the Internet. We would always go back to an ISP splash page.
At this point our ISP stated there was nothing else they could do as we could connect going directly through the router. We tried changing our two internal DNS servers Forwarders to our new ISP DNS records and still could not connect. The old DNS Forwarders had been in there for years and we did not even recognize them but they always seemed to work. What finally solved it was we used Google's DNS servers of 126.96.36.199 and 188.8.131.52 and put them in the router, the firewall and the DNS forwarders.
Our question is do the DNS forwarders always have to match the Firewall and the DNS records in the router and shouldn't the ISP have informed us and assisted also?