Question : .edu address not accessible thru private network on campus

I work for a sports marketing company and one of our offices is on campus of a university.  We acquired them from another company and when we took them over, we gave their private network and server public DNS entries.  Ever since, none of the student interns have been able to get on the universities .edu website.

Our private network is using the same internet as the rest of the campus and I can't figure out why I can't access the school's website from within our private network on that campus.  Of course I can access other .edu sites from these computers but not the local one.

I've tried changing the public DNS entries to different ones but that has not worked.  Just wondering if someone can tell me why they can't access their own school's website within the private network on the campus.  Thanks in advance.

Answer : .edu address not accessible thru private network on campus

Most organizations implement a firewall at the network border.  The firewall not only protects them from outside attackes, but it also allows them to remap addresses from the public address space into the provate address space.  

If you are getting the public address for the local server, then the request has to leave the firewall, then come right back in -- and this is prevented by many firewalls as a security issue.  

The solution is to use a separate DNS server for in-house use, which provides the INTERNAL address of the server for inside users, but it just maps to the same name.  This is often called "Split DNS" or "Split-Brain DNS", and requires that you manually configure the internal address on the inside of the firewall in the local DNS server.  If the DNS server is outdated or otherwise unavailable, then you may be getting the public address instead.

To test this, try to PING the server by its full name, and note what address you get.  Then, go to another computer on campus (one that works) and repeat the process.  You'll likely get the internal address, then.  To address it, check the DNS settings on both systems (IPCONFIG /ALL for Winders boxes) and change the one that doesn't work to the settings of the one that does.

For more info, google "split DNS"...