ELAN Agent is typically deployed as an inline level 2 enforcement device. It sits between the WAN connection and the switches and should be connected on every VLAN segment on a trunk port (all VLANs tagged) to maximize it visibility on the network. It should also receive RADIUS authentication/accounting request from the switches and be able to connect via SNMP to the switches.
All devices on the network can share the same IP (v4/v6) subnet while being isolated by VLAN. When a device is authorized to access another vlan, it is “bridged” on it, so that all zero-conf services are available.
DHCP/DNS services are not part of ELAN agent services but it offers connectivity to those services even if located on another VLAN.