Cisco Nexus 9000 Series - Enabling or Disabling VRF Support for the DHCP Relay Agent

DETAILED STEPS
PurposeCommand or Action
Enters global configuration mode.switch# configure terminal
Step 1
Enables the DHCP relay agent to insert and remove Option
82 information on the packets that it forwards. The Option
switch(config)# [no] ip dhcp relay information option
Step 2
82 information is in binary ifindex format by default. The
no option disables this behavior.
Programs Option 82 with the VLAN + slot + port format.
This command is applicable only for SVIs. The no option
disables this behavior.
(Optional) switch(config)# [no] ip dhcp relay sub-option
circuit-id customized
Step 3
Configures Option 82 to use encoded string format instead
of the default binary ifindex format. The no option disables
this behavior.
(Optional) switch(config)# [no] ip dhcp relay sub-option
circuit-id format-type string
Step 4
For VLANs and SVIs:
• When this command and the ip dhcp relay sub-option
circuit-id customized command are both configured,
the ip dhcp relay sub-option circuit-id format-type
string command is programmed.
• When the ip dhcp relay sub-option circuit-id
format-type string command is removed, the ip dhcp
relay sub-option circuit-id customized command is
programmed.
• When both commands are removed, the ifindex is
programmed.
For other interfaces, if the ip dhcp relay sub-option
circuit-id format-type string command is configured, it
is used. Otherwise, the default ifindex is programmed.
Displays the DHCP relay configuration.(Optional) switch(config)# show ip dhcp relay
Step 5
Displays the DHCP configuration.(Optional) switch(config)# show running-config dhcp
Step 6
Saves the change persistently through reboots and restarts
by copying the running configuration to the startup
configuration.
(Optional) switch(config)# copy running-config
startup-config
Step 7
Enabling or Disabling VRF Support for the DHCP Relay Agent
You can configure the device to support the relaying of DHCP requests that arrive on an interface in one VRF
to a DHCP server in a different VRF.
Before you begin
You must enable Option 82 for the DHCP relay agent.
Cisco Nexus 9000 Series NX-OS Security Configuration Guide, Release 9.x
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Configuring DHCP
Enabling or Disabling VRF Support for the DHCP Relay Agent