Home network with a /29 static 5-IP block.

[derekc]

I work in IT field and I have a home network with a comcast /29 static 5-IP block. I run a Windows Domain inside with 2 servers each running as Active Directory DNS server with 1:1 NAT to an real IP (50.193.xx.93 and 50.193.xx.90) thru a sonicwall firewall. Rest of the clients are dynamic NAT to another real IP (50.193.xx.89) - the WAN of the sonicwall. 
So, my inside clients resolve host name to IP via the 1 of the 2 DNS servers (of which they forward the request to OpenDNS) and they go out to Internet thru sonicwall WAN 50.193.xx.89.

How do I figure OpenDNS to work with my scenario? Would the $19.95 OpenDNS VIP allow such configuration?? (I prefer to try it out before paying.) Or I have to use their business options?

[rotblitz]

It is easy to see what public source IP address OpenDNS sees from your DNS lookups with these commands, executed on a specific device you want to use OpenDNS with:

   nslookup -type=txt debug.opendns.com.              (The "source" TXT field will contain the source IP address and port for that lookup.)

   nslookup myip.opendns.com.                              (The returned IP address is your public source IP address.)

   nslookup whoami.akamai.net.  ns1-1.akamaitech.net           (Same as before, 3rd party tool.  Cannot work if DNS is restricted as you said.)

All of these should return one of your five gateway addresses.