Multi-WAN DNS Servers
Obviously you can have as many "WAN" connections on pfSense as you want, my question is about the DNS entries those connections. Under General Setup you only have room for 4 dns servers. Assuming I only use one for each WAN connection, this really limits me to 4 WAN connections. Is there another way to configured DNS servers for WAN connections or is there any way we can increase this number? The entry should really be an expandable list like there are in so many other parts of the system IMHO. I could probably get away with simply not putting in DNS for the additional connections but in the interest of completeness I would like the option.
Also on an unrelated note. When pfSense has no active internet connection but has a DNS server configured that is not accessible any page that requires a DNS lookup (ie: Dashboard's Update Check) hangs for a long time and whole webconfigurator hangs. I figured this might have been part of the reason why localhost was added as the primary dns server for the router which would then proxy the dns queries to the other configured dns servers but this does not seem to be making any difference.
Unless your DNS server only responds to your IP, then even if the link is down, the other links can still carry the DNS lookups to your other carriers. I agree that having the ability to add more DNS would be okay. You can also use national servers like the 2 google and the 2 AT&T (184.108.40.206, 220.127.116.11, 18.104.22.168, and 22.214.171.124) and all your carriers would work and you would not have a long list of DNS servers to try, keeping lookup times down.
I know it's been a while, and I forgot about this post until just now since I didn't get the reply email.
I think the issue that comes in with trying to share the configured DNS servers between WAN connections is if you set a gateway for them. If you do not set a gateway for them, does the system use the default gateway then instead? In which case before they would stop working when the default gateway went down, of course now in 2.0.1 we have the neat option to have the default gateway switch with failovers which should solve that problem if it exists.
Yes,if you don't set a gateway it will try the default. It should switch with failures as you mentioned. However; unless there is some dyer need for using ISP assigned DNS server, I would use a national one or public one. I would even go so far as to setup 2 of my own before using so many ISP based DNS servers.