Can’t see DOMAIN

Have a Domain. Have 5 separate LANs, each with their own IPs. Domain Controller is Windows Server 2000. LAN1 is 10.0.10.0 255.255.255.0, LAN2 is 10.0.20.0 255.255.255.0, Lan 3 is 10.0.30.0 255.255.255.0, etc. Domain Controller is in LAN2. Having problem with WINDOWS98 machines in LAN1, LAN3, LAN4, and LAN5. Get message “No Damain Server was available to validate your password…….” No problems with the same client machines when they are on LAN2. No WINS, is all DNS. HELPPPPPPP