R3303-HP HSR6800 Routers Layer 3 - IP Services Configuration Guide

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DHCP snooping support for Option 82
Option 82 records the location information about the DHCP client so the administrator can locate the
DHCP client for security control and accounting purposes. For more information, see "Configuring the
DH
CP relay agent."
If DHCP snooping supports Option 82, it handles clients' requests according to Option 82, if any. Table
4 de
scribes the handling strategies.
If a reply returned by the DHCP server contains Option 82, the DHCP snooping device removes 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 DHCP request
has…
Handling
strate
gy
Padding format
The DHCP snooping device…
Option 82
Drop N/A 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
Forward 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.