Dhcp Snooping Support For Option 82; Recommended Configuration Procedure - HP 1910 User Manual

Table 99 Roles of ports
Device
Switch A
Switch B
Switch C

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, see
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, the DHCP
snooping device forwards it directly.
Table 100 Handling strategy of DHCP snooping support for Option 82
If a client's requesting
message has...
Option 82
no Option 82

Recommended configuration procedure

Step
1. Enabling DHCP snooping
Untrusted port
GigabitEthernet 1/0/1
GigabitEthernet 1/0/3 and
GigabitEthernet 1/0/4
GigabitEthernet 1/0/1
Handling
strategy
Drop
Keep
Replace
N/A
Remarks
(Required)
By default, DHCP snooping is disabled.
Trusted port disabled from
recording binding entries
GigabitEthernet 1/0/3
GigabitEthernet 1/0/1
GigabitEthernet 1/0/3 and
GigabitEthernet 1/0/4
The DHCP snooping device will...
Drop the message.
Forward the message without changing Option 82.
Forward the message after replacing the original Option 82
with the Option 82 padded in normal format.
Forward the message after adding the Option 82 padded in
normal format.
287
Trusted port enabled to
record binding entries
GigabitEthernet 1/0/2
GigabitEthernet 1/0/2
GigabitEthernet 1/0/2
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