dhcp / giaddr / configuration for giaddr update
if a dhcp server is connected to a router that connects many different
subnets, how does the dhcp server know which subnet a dhcp request
came from? does this information come from the giaddr field of the
dhcp request packet? if yes, is the value of this field set to the
address of the of the router interface that originally received the
packet or the router interface that the packet is forwarded through?
and how is the router configured to know which interface to forward
dhcp requests through?
and does the giaddr update itself require any configuration of the
router device or does the router know to update it automatically? if
it requires configuration, how is it done? thanks for reading