Bubbalouie
Technical User
I'm not sure that's a good Subject line, but I'm thoroughly confused by what is going on and it's the best I can come up with. I'm not an expert in DNS issues and really need one bad!
Anyway, I have a central site with multiple remote sites. The remote sites are connected back to the central location using site-to-site vpn's.
At the central site, I have a couple of WIN2K3 servers running DNS, DHCP, etc. for my domain (myinternaldomain.local). I also have a Linux based mail server running that is not part of the domain though it does have a static ip assigned to it from the local subnet. The domain name the email server uses (myexternaldomain.com) is used by a third party marketing/web developing vendor and the only thing I really have to do with it is the mail server which is mail.myexternaldomain.com. The Linux box has a public IP from my ISP, an MX record and works just fine.
The remote locations have DHCP running on their local routers and are on their own subnets.
When I use the two WIN2K3 servers for DNS at the remote sites I can login to the myinternaldomain.local but I cannot get to the email server and users are unable to bring up their webmail. Ping, tracert and NSLOOKUP by the fqdn of the mail server all resolve to the internal static ip of the mail server. I can not ping the internal IP of the server across the network. Other servers, all part of the domain work fine.
Ping, tracert and NSLOOKUP by the fqdn of the mail server at the central location also resolves to the local ip but everything works just dandy there.
I can use the the local router as the first DNS server in the DHCP section of the remote location's router config's where I have a static route defined to the public IP of the email server and the users can get to their email fine then. They just can't get authenticated on the dang domain and have to login locally or with cached credentials.
It's quite the Catch 22 situation...
Anyway, I've been approaching this as a routing issue, but now wonder if it's some simple DNS thing I'm overlooking. The mail server does not show in DNS management but somehow I am resolving the fqdn to the internal IP at the central location while it is invisible at the remote locations though all domain member servers at the central location are fully accessible at the central and remote locations. I'm wondering if there is some type of record I need to add to my DNS setup so that all my workstations regardless of their location resolve mail.myexternaldomain.com to the public ip address instead of the internal ip address?
Any insights would be greatly appreciated!
Anyway, I have a central site with multiple remote sites. The remote sites are connected back to the central location using site-to-site vpn's.
At the central site, I have a couple of WIN2K3 servers running DNS, DHCP, etc. for my domain (myinternaldomain.local). I also have a Linux based mail server running that is not part of the domain though it does have a static ip assigned to it from the local subnet. The domain name the email server uses (myexternaldomain.com) is used by a third party marketing/web developing vendor and the only thing I really have to do with it is the mail server which is mail.myexternaldomain.com. The Linux box has a public IP from my ISP, an MX record and works just fine.
The remote locations have DHCP running on their local routers and are on their own subnets.
When I use the two WIN2K3 servers for DNS at the remote sites I can login to the myinternaldomain.local but I cannot get to the email server and users are unable to bring up their webmail. Ping, tracert and NSLOOKUP by the fqdn of the mail server all resolve to the internal static ip of the mail server. I can not ping the internal IP of the server across the network. Other servers, all part of the domain work fine.
Ping, tracert and NSLOOKUP by the fqdn of the mail server at the central location also resolves to the local ip but everything works just dandy there.
I can use the the local router as the first DNS server in the DHCP section of the remote location's router config's where I have a static route defined to the public IP of the email server and the users can get to their email fine then. They just can't get authenticated on the dang domain and have to login locally or with cached credentials.
It's quite the Catch 22 situation...
Anyway, I've been approaching this as a routing issue, but now wonder if it's some simple DNS thing I'm overlooking. The mail server does not show in DNS management but somehow I am resolving the fqdn to the internal IP at the central location while it is invisible at the remote locations though all domain member servers at the central location are fully accessible at the central and remote locations. I'm wondering if there is some type of record I need to add to my DNS setup so that all my workstations regardless of their location resolve mail.myexternaldomain.com to the public ip address instead of the internal ip address?
Any insights would be greatly appreciated!