Hello,
There is a great flexibility in the DHCP service - you can have a single DHCP server assigning IP addresses for all VLANs, or each VLAN can use a distinct and separate DHCP server, or a combination of these two approaches.
Assuming that the DHCP server is attached to the same VLAN it is supposed to assign IP addresses for, you do not need to configure anything special except the DHCP server itself: configure the usual IP parameters that should be handed over to clients.
If the DHCP server is placed outside the VLAN that it serves, two things have to be configured: first, the DHCP server in the identical way as described before (nothing changes here), and second, the router that connects this VLAN to the rest of the network must be configured with DHCP Relay function that will forward the DHCP messages from clients to the appropriate DHCP server and back. This is performed on Cisco routers using the ip helper-address X.X.X.X command that is placed on the interface/subinterface connected to the VLAN where the clients reside.
Best regards,
Peter
