HP V1910, Руководство пользователя

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2 describes roles of the ports shown in a .
2.
Roles of ports
Device Untrusted port
Trusted port disabled from
recording binding entries
Trusted port enabled to
record binding entries
Switch A GigabitEthernet 1/0/1 GigabitEthernet 1/0/3 GigabitEthernet 1/0/2
Switch B
GigabitEthernet 1/0/3 and
GigabitEthernet 1/0/4
GigabitEthernet 1/0/1 GigabitEthernet 1/0/2
Switch C GigabitEthernet 1/0/1
GigabitEthernet 1/0/3 and
GigabitEthernet 1/0/4
GigabitEthernet 1/0/2
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 the chapter “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 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.
If a client’s requesting
message has…
Handling
strategy
The DHCP snooping device will…
Option 82
Drop Drop the message.
Keep Forward the message without changing Option 82.
Replace
Forward the message after replacing the original Option 82
with the Option 82 padded in normal format.
no Option 82 —
Forward the message after adding the Option 82 padded in
normal format.
DHCP snooping configuration task list
Complete the following tasks to configure DHCP snooping:
Task Remarks
Enabling DHCP snooping
Required
By default, DHCP snooping is disabled.