H3C Technologies H3C S12500 Series Switches - Manual (Page 90)

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DHCP snooping support for Option 82
Option 82 records the location information about the DHCP client. The administrator can locate the
DHCP client for security control and accounting purposes. For more information, see " DHCP overview ."
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
Table 4 .
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, the DHCP
snooping device forwards it directly.
Table 4 Handling strategies of DHCP snooping
If a client's
requesting message
has…
Handling
strategy
Padding format The DHCP snooping switch…
Option 82
Drop Random Drops the message.
Keep Random
Forwards the message without changing
Option 82.
Replace
normal
Forwards the message after replacing the
original Option 82 with the Option 82 padded
in normal format.
verbose
Forwards the message after replacing the
original Option 82 with the Option 82 padded
in verbose format.
user-defined
Forwards the message after replacing the
original Option 82 with the user-defined
Option 82.
Append
normal
Forwards the message without changing
Option 82.
verbose
Forwards the message without changing
Option 82.
private
Forwards the message after adding sub-option
9 to option 82 or adding content to sub-option
9 that option 82 contains.
standard
Forwards the message without changing
Option 82.
user-defined
Forwards the message without changing
Option 82.
no Option 82 N/A normal
Forwards the message after adding the Option
82 padded in normal format.