I'm running Windows server 2003 and exchange 2007. I can't ping the public ip of my Exchange internally but i can do it externally may be becuase it causing the loop? so the issue is here if i'm on my internal wi-fi i can configure the mobile devices to mail1.example.com and i need to use outside internet or wireless. so how do i setup my dns to resolve this issue. thanks

can you resolve external names in general, like when you browse in ie or is just your mailserver not resolved? your dns has an internet dns as dns forwarder to look up external adresses? do you use a firewall? if so, its potentially blocking the icmp protocoll rendering ping unusable for the external ip from the inside

If you have a public IP and your Exchnage server is being NAT'd by that public IP, you wont be able to hit the Exchange server by its public IP. You will need to access it via its private IP address from within the network. If your internal and external domain name is the same, it will require you to have a split-DNS infrastracture where your external DNS services contains the public IPs and services your clients, and your internal DNS would have a combination of private and some public (publics which are not NAT'd) IPs. Your internal clients would always point to your internal DNS servers. Visit: anITKB.com, an IT Knowledge Base.

FZB Yes i can resolve external name without any issues yes it forwarding to external dns too yes we do have firewall but i can ping from the outside to the public ip which is translating to the private ip. Jorqe If you have a public IP and your Exchnage server is being NAT'd by that public IP, you wont be able to hit the Exchange server by its public IP. You will need to access it via its private IP address from within the network. - so if this is the case then how do I configure the mobile device becuase sometime your within the building using the internal DNS and when you are outside you are using publicinternet? as you asid split-dns , can it fix . if so then how?

does that articles solves the problem where it says remove all the roots and disable the recursion http://www.isaserver.org/tutorials/You_Need_to_Create_a_Split_DNS.html

Hello Vministrator, "so if this is the case then how do I configure the mobile device becuase sometime your within the building using the internal DNS and when you are outside you are using publicinternet?" I assume that if its a mobile device, a laptop, it will acquire an IP from the internal DHCP servers when connected internally. The DHCP scope will provide the client with the internal DNS client settings. When the mobile device is outside the network, its going to be forced to use a public DNS servers (ISPs most likely) when attempting to resolve names. If that mobile device connects back via VPN, its going to use the internal resources once again. I don't see a conflict here. "does that articles solves the problem where it says remove all the roots and disable the recursion" I am not sure what you are referring to. This action is usually taken against DNS servers servicing internet clients, as External DNS Servers. Visit: anITKB.com, an IT Knowledge Base.

Do you allow ICMP to the public interface? If ICMP is disabled, you won’t be able to ping the external IP address. You need to configure your internal and external DNS zone properly. Internal DNS zone should point it to the internal IP address and external DNS zone should point it to external IP of EX server. So from external network, you can’t access mail1.exam ple.com using internet browser? Santhosh Sivarajan | MCTS, MCSE (W2K3/W2K/NT4), MCSA (W2K3/W2K/MSG), CCNA, Network+ Houston, TX http://blogs.sivarajan.com/ http://publications.sivarajan.com/ This posting is provided "AS IS" with no warranties, and confers no rights.