I need to have 524 users on lan igned the ip address?

Well first you can use a Cl A for the ip range , then you need to have a DCHP server ruuning it and last the config on the wk will be TCP/IP = DCHP , this means that ALL the clients will have dchp config , so that way the dhcp server can ign one to them.If you need more info on the sercurity part just let me know ok