one to one NAT 1

[yisrael]

I have a particularly confusing DNS issue. I know that this has to have been dealt with before, and I’ve found a sort of solution, but I haven’t been able to really crack this one. This issue has been gnawing at me for some time… so here it goes:

We have our web and email hosting off site. I therefore chose to use the ISP’s DNS server. I have the ability to modify any DNS setting at will. I have a few servers in house that are hosting services to the outside world, for example web services. The configuration that I am using is one-to-one NATing. The way I have these set up is that the server has an internal IP address and the firewall forwards requests from a specific external IP address to the “internal machine”.

For example, I have a server with an IP address of 192.168.1.4. I allow port 4505 from 216.146.78.99 to forward to the internal 192.168.1.4:4505.

The problem is as follows: the server’s DNS name. I have the DNS server listing of norman.spertus.edu as 216.146.78.99. This works beautifully for the outside world. The problem is internal users. The internal users get the DNS entry above as an external IP address and don’t know what to do with that. I have a workaround that I’ve implemented and set up a Hosts file on the local machines. I find this to be quite a pain, and I would like to upgrade our Domain from NT to 2000, but 2000 requires a DNS server functioning properly. I have seen postings to create 2 DNS servers. I have been unsuccessful with that implementation also.

I am sorry for all the verbiage. Any ideas would help me significantly. Thank you.

Yehoshua Israel

 

[GlenJohnson]

Are you using dhcp? Glen A. Johnson
Johnson Computer Consulting
MCP W2K
glen@johnsoncomputers.us

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[yisrael]

Yes. I set up in the DHCP options to point to the DNS severs from our ISP. Any ideas?

 

[GlenJohnson]

Since I don't use dhcp, this is a long shot. Can you go into the advanced settings and place the dns there? Would probably be the same as using a host file. Just grasping for the time bieng. Remove the hosts file from a pc, and see what ipconfig /all shows us. Glen A. Johnson
Johnson Computer Consulting
MCP W2K
glen@johnsoncomputers.us

Want to get great answers to your Tek-Tips questions? Have a look at FAQ219-2884
"If I have made any valuable discoveries, it has been owing more to patient attention than to any other talent."
Sir Isaac Newton (1642-1727)

 

[yisrael]

I have tried this type of approach before. DHCP only points you to a proper DNS server. If I specify my own IP address it has the same effect. The problem I've run into is more confusing: if I specify just my local DNS server, I can't do any outside name resolution - no browsing anything on the web. If I specify only the outside DNS server, internal name resolution doesn't work. If I specify both DNS servers once again it seems to only resolve internal addresses. The last point to me is the most confusing. I thought that DNS keeps looking for name resolution from any of the servers listed....

I am using the DNS server that bundles with NT 4.0.

Any ideas? Thank you for your help so far...

 

[GlenJohnson]

DNS is supposed to do just that. I have two dns servers, (No dhcp) and on my local machines I have my internal dns servers listed only. On the servers, I have themselves and my outside isp dns numbers. If a local machine can't resolve the name to ip internally, one of the two dns machines here goes out and resolves it, then it resides in cache. Has this always been going on or did it just start. Have you tried ipconfig /flushdns? Glen A. Johnson
Johnson Computer Consulting
MCP W2K
glen@johnsoncomputers.us

Want to get great answers to your Tek-Tips questions? Have a look at FAQ219-2884
"If I have made any valuable discoveries, it has been owing more to patient attention than to any other talent."
Sir Isaac Newton (1642-1727)

 

[yisrael]

It Worked!! Great!!! I have been soooooo close to the solution for the last 8-10 months!! Currently, I set up my local DNS to have an NS record of my ISP's server but I forward everything to my local DNS server. The only thing I need to define are the local DNS names and the

http://www aliases.

My new problem is how to resolve all DNS requests to the main domain. It looks like my ISP uses a * to resolve anything with our domain name e.g. junk.domainname.com to automatically go to the

http://www.domainname.com.

I tried doing the same thing with my Microsoft DNS server to no avail. Any new ideas?