Cannot Connect by Name Inside Local Net 2

[RH610]

We have a Web server (win2k) in our office. From a PC in the office we can only connect to it by IP address; not by name. From a PC outside the office we can connect to it by IP or name. Can connect by IP or name to outside servers from PC in the office. I've tried most DNS troubleshooting that I know of (ping, DNS lookup, etc.) and am currently at a loss. This used to work. Will provide any details that might help anyone help me, if you'll let me know what details those might be.

Thank You

 

[jjeffm]

RH610:
Do you have an internal DNS server? is the service running?
Do you have an internal WINS server?
From the sounds of it you have nothing resolving names to address's? if you type 'NSLOOKUP' AT A CMD LINE and type in a known name of a local machine, if your dns server is working you should get the address and name back. i think thats why you can hit stuff from the web but not inside.
At least that's where i'd start...

 

[RH610]

Thanks for the reply. We do not use and internal DNS or WINS server. We can hit everything from the inside except our WEB server by name. I think it may be some kind of DNS problem on that WEB server, but I don't have clue as to what it might be. I will try the NSLOOKUP command. Anything further will be mightily appreciated.

 

[ChrisAC]

The reason for this is that your DNS resolver on your local machine is resolving the external name to an external IP address and therefore your web client is trying to connect to a machine on the local network using the external IP address. If you put an entry in your hosts file pointing the external name to the internal private IP address then it will work by name.

The PIX firewall addresses this problem by doing DNS doctoring. For example, if the firewall has a static IP mapping for a web server and a client on the local network looks up the IP address for that server but using an external DNS server, when the DNS reply comes back through the PIX it realises that the client is trying to resolve the external IP address of a local machine and changes the DNS reply packet so that the external name is resolved to the local IP address of the server and not the 'global' address that people outside of the local network would use. However, I don't know of any other firewall that has this feature.

Chris.


**********************
Chris Andrew, CCNA, CCSA
chris@iproute.co.uk
**********************

 

[wbg34]

Edit your hosts file (ususally in c:\winnt\system32\drivers\etc) and add an entry for your web server. The hosts file gets checked before dns is queried so it will direct you to the correct computer when you use the name. Copy the host file and distribute it among your internal computers (except the web server).