Allied Telesis AlliedWare Plus Operating System Version 5.4.4C (x310-26FT,x310-26FP,x310-50FT,x310-50FP) - Manual (Page 1708)

Dynamic Host Configuration Protocol (DHCP) Commands
Software Reference for x310 Series Switches
64.10 AlliedWare Plus TM Operating System - Version 5.4.4C C613-50046-01 REV A
ip dhcp-relay agent-option
This command enables the DHCP Relay Agent to insert the DHCP Relay Agent Information
Option (Option 82) into the client-request packets that it relays to its DHCP server. This
allows the DHCP Relay Agent to pass on information to the server about the network
location of the client device. The DHCP Relay Agent strips the DHCP Relay Agent Option
82 field out of the DHCP server’s response, so that the DHCP client never sees this field.
When the DHCP Relay Agent appends its DHCP Relay Agent Option 82 data into the
packet, it first overwrites any pad options present; then if necessary, it increases the packet
length to accommodate the DHCP Relay Agent Option 82 data.
The no variant of this command stops the DHCP Relay Agent from appending the Option
82 field onto DHCP requests before forwarding it to the server.
For DHCP Relay Agent and DHCP Relay Agent Option 82 introductory information, see
“DHCP Relay Agent Introduction” on page 63.7
Syntax ip dhcp-relay agent-option
no ip dhcp-relay agent-option
Default DHCP Relay Agent Information Option (Option 82) insertion is disabled by default.
Mode Interface Configuration for a VLAN interface.
Usage Use this command to alter the DHCP Relay Agent Option 82 setting when your switch is
the first hop for the DHCP client. To limit the maximum length of the packet, use the
ip
dhcp-relay max-message-length command.
This command cannot be enabled if DHCP snooping is enabled on your switch ( service
dhcp-snooping command on page 56.24 ), and vice versa.
Examples To make the DHCP Relay Agent listening on vlan15 append the DHCP Relay Agent
Option 82 field, use the commands:
To stop the DHCP Relay Agent from appending the DHCP Relay Agent Option 82 field on
vlan15
, use the commands:
Related Commands ip dhcp-relay agent-option remote-id
ip dhcp-relay information policy
ip dhcp-relay max-message-length
service dhcp-relay
Note The DHCP-relay service might alter the content of the DHCP Relay Agent
Option 82 field, if the commands
ip dhcp-relay agent-option and ip dhcp-
relay information policy have been configured.
awplus# configure terminal
awplus(config)# interface vlan15
awplus(config-if)# ip dhcp-relay agent-option
awplus# configure terminal
awplus(config)# interface vlan15
awplus(config-if)# no ip dhcp-relay agent-option