Adding NAT to the company network tomorrow - questions

[DougK62]

A big thanks to the responders in my other thread several days ago.

Let me give my situation again. We're a small company with about 15 computers. Two of these computers are servers and the others are workstations. One server serves files and WINS, and the other serves webpages, email, and antivirus. The workstations are a mix of NT and 98, and both servers are NT. Currently, all computers have public IP numbers out of our address block given by our T1 host. The workstations and file server are on a seperate domain than the web server. The plan tomorrow is to put all of our workstations and the file server behind a NAT, and to leave the web server with a public IP out in the DMZ. From a suggestion in my previous thread, I picked up a Linksys BEFSX41 to do this.

I can easily setup the router and change all of the computers to get internet access. My concern is with the workstations "talking" to the two servers. I'm not too concerned about the file server. It will be in the same domain as the workstations still and be in the same subnet as them still so I'm assuming that it will need little changing - hopefully just a simple IP change and be done with it. My main concern is with the web server that will be moved to the DMZ. Now it's going to be on a diferent subnet than the other computers. In addition to our external website, it also hosts an internal intranet. It also handles Exchange Server 5.5 and does virus sweeps with our Norton antivirus. How is this server going to "see" the individal computers behind the NAT to do these functions properly? I'd rather not connect it directly to the NATed area.

I'm basically looking for guidance on what I can expect to change on our webserver to get it all working correctly. Does anyone have experience in a similar situation? Do some services automatically adjust to new IP surroundings?

Any suggestions or guidance is greatly appreciated :beer:

 

[Smilin]

Perhaps this...

Put the two servers with hard-set local ip's on the router and then have one of them (that doesn't need dmz) issue dhcp addresses that correspond to the router's internal network (typically 192.168.0.0) then just put the dmz one into the dmz on the router.


If you've been using public ip's for the two servers and they both have registered dns names you can just setup the new router to nat the workstations and the workstations will find the servers no problem. None of the above would be necessary. Don't forget winnt can route too. With only 15 clients any server over a 450 is going to handle file/print and routing just fine.