ECS4660-28F_Management Guide-R03

C HAPTER 48 | DHCP Commands
DHCP Relay
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DHCP RELAY
This section describes commands used to configure DHCP relay functions
for host devices attached to the switch.
DHCP Relay for IPv4
ip dhcp relay server This command specifies the DHCP server or relay server addresses to be
used by the switch’s DHCP relay agent. Use the no form to clear all
addresses.
SYNTAX
ip dhcp relay server address1 [address2 [address3 ...]]
no ip dhcp relay server
address - IP address of DHCP server. (Range: 1-5 addresses)
DEFAULT SETTING
None
COMMAND MODE
Interface Configuration (VLAN)
USAGE GUIDELINES
◆ DHCP relay service applies to DHCP client requests received on the
specified VLAN.
◆ This command is used to configure DHCP relay for host devices
attached to the switch. If DHCP relay service is enabled, and this switch
sees a DHCP client request, it inserts its own IP address into the
request so that the DHCP server will know the subnet where the client
is located. Then, the switch forwards the packet to a DHCP server on
another network. When the server receives the DHCP request, it
allocates a free IP address for the DHCP client from its defined scope
for the DHCP client’s subnet, and sends a DHCP response back to the
DHCP relay agent (i.e., this switch). This switch then passes the DHCP
response received from the server to the client.
Table 231: DHCP Relay Commands
Command Function Mode
DHCP Relay for IPv4
ip dhcp relay server Specifies DHCP server addresses for relay IC
ip dhcp restart relay Enables DHCP relay agent PE
DHCP Relay for IPv6
ipv6 dhcp relay
destination
Specifies destination address or VLAN to which client
messages are forwarded for relay service
IC
show ipv6 dhcp relay
destination
Shows destination addresses or VLAN to which client
messages are forwarded for relay service
PE