Thanks to all who asked this question: I have been able to use the
suggestions to check DNS settings at my schools. However, I am not
sure if the results make any sense. We have been having some network
problems that could be attributable to DNS issues.
Within the LAN, PTR returns a correct value. DNS appears to be set up
correctly forward and reverse.
However we are behind firewalls, NAT, proxy server is handling DNS.
DHCP comes from routers (controlled by ISP). So, if I use these
commands from outside the district, I get an error message. I am
getting an "A" record, but PTR says "host does not exist."
This is because your LAN is NAT, which means an address space of
192.x.x.x or 10.x.x.x, which are non-routable numbers. So, internally,
your DNS matches something like this:
host1.network.com IN A 192.168.1.10
If you wanted host1 to be accessible from the outside, you would need
another DNS entry at your ISP like this:
host1.network.com IN A 156.46.227.35 (or whatever public IP's you have)
Then you would need to place host1 in your router's DMZ or set up
port-forwarding or one-to-one NAT to that machine so packets from
outside could reach it on the inside.
Lastly, all your LAN machines would be set to use your internal DNS
server, which should have the proper forwarders listed, so that it
resolves any internal request, but forwards all external requests to
your ISP's DNS servers.
Now BIND 9 implements something called views which allows you to do
this all with your internal DNS, but that isn't something you can do
with ServerAdmin. I'm not sure it is even possible with 10.3.x without
installing BIND 9 on your own.
---
Eric
