H3C Technologies H3C S12500 Series Switches - Manual (Page 45)

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Figure 21 Sub-option 2 in normal padding format
2. Verbose padding format
The padding contents for sub-options in the verbose padding format are:
{
Sub-option 1—Contains the user-specified access node identifier (ID of the switch that adds
Option 82 in DHCP messages), and type, number, and VLAN ID of the interface that received
the client's request. The VLAN ID field has a fixed length of 2 bytes. All the other padding
contents of sub-option 1 are length variable. See Figure 22 .
Figure 22 Sub-option 1 in verbose padding format
{
Sub-option 2—Contains the MAC address of the DHCP relay agent interface or the MAC
address of the DHCP snooping switch that received the client's request. It has the same format
as that in normal padding format. See Figure 21 .
3. Private padding format
{
Sub-option 1—Contains the VLAN ID of the interface that received the client's request, module
(slot number of the receiving port), and port (port number of the receiving port). The value of the
sub-option type is 1.
Figure 23 Sub-option 1 in Private padding format
{
Sub-option 2—Contains the MAC address of the DHCP relay agent interface or the MAC
address of the DHCP snooping device that received the client's request. The value of the
sub-option type is 2.
Figure 24 Sub-option 2 in Private padding format
{
Sub-option 9—Contains the sysname and the primary IP address of the Loopback0 interface.
The value of the sub-option type is 9.