[Settings]
IPRELAY_0=192.168.2.1  ; Default: -
…
IPRELAY_9=192.168.10.1

IPRELAY_x is the definition of the DHCP Server address where the relay agent sends all requests coming in from IPBIND_x. Please see the description in the INI file overview about relay agents to learn more. IPRELAY_x is supported since V2.0.