A DHCP server accepts address assignment requests and renewals, and assigns the IP addresses from predefined groups of addresses
contained within Distributed Address Pools (DAPS). DHCP servers can also be configured to supply additional information to
the requesting client such as subnet mask, domain-name, the IP address of the DNS server, the default router, and other configuration
parameters. DHCP servers can accept broadcasts from locally attached LAN segments or from DHCP requests that have been forwarded
by other DHCP relay agents within the network.
The DHCP proxy performs all the functions of a relay and also provides some additional functions. The DHCP proxy conceals
DHCP server details from DHCP clients. The DHCP proxy modifies the DHCP replies such that the client considers the proxy to
be the server. In this state, the client interacts with the proxy as if it is the DHCP server.
DHCP Service-based Mode Selection
As part of DHCP service-based mode selection feature, a new mode called DHCP base is introduced. If an interface is configured
in the DHCP base mode, then the DHCP selects either the DHCP proxy or the DHCP server mode to process the client request by
matching option 60 (class-identifier) value of the client request with the configured value under the DHCP base profile.
The pool is configured under server-profile mode and server-profile-class submode. The class-based pool selection is always
given priority over profile pool selection.
The DHCPv6 server-profile-class submode supports configuring DHCP options except few (0, 12, 50, 52, 53, 54, 58, 59, 61, 82,
and 255 ).
profile DHCP_BASE base
match option 60 41424344 profile DHCPv6_PROXY proxy
match option 60 41424355 profile DHCPv6_SERVER server
default profile DEFAULT_PROFILE server
relay information authenticate inserted
profile DHCPv6_PROXY proxy
helper-address vrf default 10.10.10.1 giaddr 0.0.0.0
profile DHCPv6_SERVER server
lease 1 0 0
profile DEFAULT_PROFILE server
lease 1 0 0
interface gigabitEthernet 0/0/0/0 base profile DHCP_BASE