We have a small network in our office. A one-port DSL router provides internal IP addresses automatically. It uplinks to an 8-port hub which uplinks to a 4-port wireless router which has DHCP disabled. The various computers are attached to the hub or the wireless router by cable. We are not currently using any wireless connections. All of our computers are configured to obtain an IP address automatically.
We also have a web server in the office, which was forwarded any http calls that were sent to our permanently assigned external IP address.
Recently, we physically rearranged the room that contains the networking equipment. In the process we powered down the network and unplugged many of the cables. When we plugged them back in they may have gone to a different port or to the hub when they had been plugged into the router or vice versa. (We can't think of any reason that the specific port would matter.) Other than that, we did not (hopefully) change anything about the network.
Since the move we have been having two problems:
1. We are unable to get http forwarding to work. Somehow it was apparently working in the past in conjunction with the dynamically assigned address. After the move, the server received a different address but when we tried assigning http forwarding to that address it did not resolve the problem.
2. We are getting error messages about IP address conflicts. These are occurring on the server and one other machine. How can this happen when all addresses are assigned dynamically?