H3C Technologies H3C WX6000 Series Access Controllers - Manual (Page 396)

38-3
Figure 38-2 Configure trusted ports in a cascaded network
DHCP Snooping Support for Option 82
Option 82 records the location information of the DHCP client. The administrator can locate the DHCP
client to further implement security control and accounting. For more information, refer to
Relay agent
option (Option 82) .
If DHCP snooping supports Option 82, it will handle a client’s request according to the contents defined
in Option 82, if any. The handling strategies are described in the table below.
If a reply returned by the DHCP server contains Option 82, the DHCP snooping device will remove the
Option 82 before forwarding the reply to the client. If the reply contains no Option 82, it forwards it
directly.
If a client’s requesting
message has…
Handling
strategy
Padding
format
The DHCP snooping device will…
Drop Random Drop the message.
Keep Random Forward the message without changing Option 82.
normal
Forward the message after replacing the original
Option 82 with the Option 82 padded in normal
format.
Option 82
Replace
verbose
Forward the message after replacing the original
Option 82 with the Option 82 padded in verbose
format.
— normal
Forward the message after adding the Option 82
padded in normal format.
no Option 82
— verbose
Forward the message after adding the Option 82
padded in verbose format.