Accton Technology ES4626 - Manual (Page 334)

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10.3.2.6 ip helper-address
Command: ip helper-address
no ip helper-address
Function: Specifies the destination address for the DHCP relay to forward UDP packets.
The “no ip helper-address “ command cancels the setting.
Default:
Address for forwarding DHCP broadcast packet is set on DHCP relay by default.
Command mode: Interface Mode
Usage Guide: The DHCP relay forwarding server address corresponds to the port
forwarding UDP, i.e., DHCP relay forwards corresponding UDP packets only to the
corresponding server instead of all UDP packets to all servers. The default setting of
DHCP relay is to forward DHCP packets on UDP port 67 to the DHCP server. When this
command is run after “ip forward-protocol udp “ command, the forwarding
address configured by this command receives the UDP packets from instead of
default DHCP packets. If a different set of UDP forwarding protocol and receiving server
address is to be set, the combination of “ip forward-protocol udp “ command
and this command should be used for configuration.
10.3.2.7 ip dhcp relay information policy drop
Command: ip dhcp relay information policy drop
no ip dhcp relay information policy drop
Function: When layer 3 switches are used as DHCP relays, this command sets the relay
forwarding policy to drop DHCP packets; the “no ip dhcp relay information policy
drop ” command allows DHCP packets forwarding.
Default: DHCP relay forwards DHCP broadcast packet by default.
Command mode: Global Mode
Usage Guide: When the DHCP relay should not forward DHCP packets for some reason,
this command can be used to disable DHCP packet forwarding on DHCP relay.
Example: Disabling DHCP broadcast packet forwarding on the layer 3 switch.
Switch(Config)# ip dhcp relay information policy drop
10.4 DHCP Configuration Example
Scenario 1:
Too save configuration efforts of network administrators and users, a company is
using ES4624-SFP/ES4626-SFP switch as a DHCP server. The Admin VLAN IP address
is 10.16.1.2/16. The local area network for the company is divided into network A and B
according to the office locations. The network configurations for location A and B are
shown below.