We have two network segment in our small office (14 workstations) separated by hubs. Now we have added a routed. I changed the IP address of segment/server A, no problem. Change IP address on segment/server B(both DHCP)now some of the workstations on segment B cannot see that server or get to its shares. The DHCP configuration on server B had not been completed so I did that. Then change a workstaiton from static IP address yet nothing works. I know this is long but I wanted to give some detail. Someone help. Thanks in advance

It's not long enough. I need to know more about the addresses and routing. If you had two segements seperated by a hub, you still really only had one segment. In order to have to segments,(subnets) you need to have two IP address ranges, one for each subnet. The routers must know how to route between the two. Your DHCP server must be set up with two scopes, one for each subnet or you need to have a DHCP server on each subnet. Depending on your router, you may also need a DHCP relay agent. What addresses, subnet masks and default gateways are applied to each subnet. This might just be a problem of improper IP addresses, masks or gateways so give me the details on the IP addressing.

Hope I can explain this and make sence. Hub/Server B is mask 255.255.0.0 Hub/server A is mask 255.255.255.0 We had installed a Cisco router now connected to hub A. I changed to IP address of the servers per the router tech support. On Server A everything went fine. But still only some of the computer can access the internet via the router. However my biggest problem now is that after changing the IP address of Server B it's clients can no longer see it in network neighborhood nor access shared files. The DHCP configurations had not been completed (all the clients had static IP)so I did that then went to the clients. Changed them to optain IP, ipconfig /release, ipconfig /renew. They still can not get to shared files. I am using NT on all machines. The router is NAT enabled for 2 networks. This is blowing my mind, please help.

Stephanie, Did you modify your routing table any? This is what will tell NT which groups of IP's belong to which subnet. Type "route print" at a command prompt to see what it currently shows. It shows by IP group which subnet mask and Default Gateway it will use.

Rick Thanks. The router was config. by the provided. I want that informaiton for confirmation. However, right now my pressing concern is getting those workstations back communicating with their domain shares.

Stephanie, the bottom line is that the computers on subnet A all have valid address for subnet A and the ones on subnet B have valid address for B. So knowing the IP address of the clients will help. Let see if I can explain a bit. Lets say you are using an IP address range of 10.1.x.x with a mask of 255.255.0.0 on subnet A. That mask tells IP that the 'network' is the 10.1 network. All clients on that subnet must have an IP address of 10.1.x.x and the 255.255.0.0 mask. The last two X's, called octets can be pretty much any number between 1 - 254. (this isn't entirely true but let's ignore some techy details for now). For some reason they have the other network using a mask of 255.255.255.0. This will work but this tells IP to use the first 3 octets to define the network. So lets give the computers on subnet B address in the 10.2.1.x range. This puts both sets of computer on different subnets. The router must also have the proper IP address for the interface that is attached to the subnets. So the router will have an IP address of 10.1.0.1, mask 255.255.0.0 for one interface, and an IP of 10.2.1.1, mask 255.255.255.0 for another interface. Since you are doing routing you will a need to define a default gateway on the client machines also. The default gateway is simply the IP address of the router interface local to those pc's. So for the clients on subnet A, their default gateway would be 10.1.0.1 (the IP address of the router), and for the clients on subnet B, their default gateway would be 10.2.1.1. (the IP address of the other interace of the router). I hope this helps but it sounds like the address may have gotten screwed up and the packets are not being routed properly. This may not be a problem with the router if the IP configuration is incorrect on the clients. If you are handing out addresses via DHCP, the rules do not change, you just make sure the DHCP server is passing out the right info. I hope this helps. Give us some info on actual IP addresses that you are using.

Sounds like you need WINS servers on both subnets.