From the description of problem it's quite hard to pinpoint the problem. But it looks like you have congestion on the network and you may need to use switches in place of Hubs and do some segmentation of the network. Also having a DHCP server to assign the IP address along with other parameters would be a good idea.
Related Q&A from Sudhanshu Gupta, Routing and Switching Expert
Unmanaged Linksys switches don't know where to send BootP and DHCP requests. Find out what to do to fix the problem of unmanaged switches and DHCP ...continue reading
Have a question for an expert?
Please add a title for your question
Get answers from a TechTarget expert on whatever's puzzling you.