D-Link DGS-3612G - xStack Switch Reference Manual page 66

The Implementation of DHCP Information Option 82
The config dhcp_relay option_82 command configures the DHCP relay agent information option 82 setting of the Switch. The
formats for the circuit ID sub-option and the remote ID sub-option are as follows:
NOTE: For the circuit ID sub-option of a standalone switch, the module field is always zero.
Circuit ID sub-option format:
1.
1
1 byte 1 byte
a. Sub-option type
b. Length
c. Circuit ID type
d. Length
e. VLAN: the incoming VLAN ID of DHCP client packet.
f. Module: For a standalone switch, the Module is always 0; For a stackable switch, the Module is the Unit ID.
g. Port: The incoming port number of DHCP client packet, port number starts from 1.
Remote ID sub-option format:
1.
2
1 byte 1 byte
1. Sub-option type
2. Length
3. Remote ID type
4. Length
5. MAC address: The Switch's system MAC address.
®
xStack DGS-3600 Series Layer 3 Managed Gigabit Ethernet Switch
2. 3. 4.
6 0 4
1 byte 1 byte
2. 3. 4.
8 0 6
1 byte 1 byte
Figure 2- 48. Circuit ID and Remote ID Sub-option Format
5. 6.
VLAN Module
2 bytes 1 byte
5.
MAC address
6 bytes
50
7.
Port
1 byte