dhcp-relay option 82
Syntax
dhcp-relay option 82 {replace [validate] | drop [validate] | keep | source-interface | validate [replace | drop]} [ip | mac]
no dhcp-relay option 82 source-interface
Description
Configures the behavior of DHCP relay option 82. A DHCP relay agent can receive a message from another DHCP relay agent having option 82. The relay information from the previous relay agent is replaced by default.
The
no
form of this command disables support for DHCP relay option 82.
Command context
config
Parameters
replace
Replace the existing option 82 field in an inbound client DHCP packet with the information from the switch. The remote ID and circuit ID information from the first relay agent is lost. Default.
validate
Validate option 82 information in DHCP server responses and drop invalid responses.
drop
Drop any inbound client DHCP packet that contains option 82 information.
keep
Keep the existing option 82 field in an inbound client DHCP packet. The remote ID and circuit ID information from the first relay agent is preserved.
source-interface
Configures the DHCP relay to use a configured source IP address for inter-VRF server reachability. Set the source IP address with the command
ip source-interface
.ip
Use the IP address of the interface on which the client DHCP packet entered the switch as the option 82 remote ID.
mac
Use the MAC address of the switch as the option 82 remote ID. Default.
Authority
Administrators or local user group members with execution rights for this command.
Example
This example enables DHCP option 82 support and replaces all option 82 information with the values from the switch, with the switch MAC address as the remote ID.
switch(config)# dhcp-relay option 82 replace mac