IP Networking

This is probably a stupid question but I am finding a tricky issue on my Solaris machines right now. I changed the hostname for my servers as requested by my superior. I had one server that lost it's entire network configuration when I rebooted. I reconfigured it with it's address and I can access it. BUT, now the developer cannot reach any of the 3 servers. I can reach them but I reach them via an internal address 192.168.x.x and he accesses them via a VPN using an external address 172.x.x.0. I did not change the IP address, only the hostname. I did think about DNS but we don't access those servers via DNS hostname.

Is there a file i'm missing I need to check to see the addressing scheme for the 172.x.x.x address? I know we have other Solaris machines with external addressing, but I cannot find their external addressing definition.

The developer will have to use the ip addresses. Are you using dhcp to assign address?
He will also have to reboot his PC at home before he tries this.

What VPN do you have?

No DHCP is in use. I will have him reboot and try. We are using... the name was on the tip of my tongue. I do know my VPN client is different than his. Mine allows me to RDP back to our network and his just creates a working tunnel in order to use the IP addresses (172.x.x.x).

I'll check the name of the VPN program later. I do'nt have my work laptop with me.