If you use the relay-option-82 statement to enable insertion of option 82 information in DHCP packets, you must also specify at least the circuit-id statement to include the agent-circuit-id suboption (suboption 1) of the DHCP relay agent information option.
If you specify the circuit-id statement, the format of the agent-circuit id information for Fast Ethernet (fe) or Gigabit Ethernet (ge) interfaces is one of the following, depending on your network configuration:
- (fe | ge)-fpc/pic/port
- (fe | ge)-fpc/pic/port:vlan-id
- (fe | ge)-fpc/pic/port:svlan-id-vlan-id
For example, the following is the agent-circuit-id format for a Gigabit Ethernet interface on Flexible PIC Concentrator (FPC) 4, PIC 1, port 1 with S-VLAN ID 122 and VLAN ID 500:
- ge-4/1/1:122-500