Dhcp Snooping Support For Option 82 - HP 10500 Series Configuration Manual

Figure 34 Configuring trusted ports in a cascaded network
Table 4 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 so the administrator can locate the DHCP
client for security control and accounting purposes. For more information, see
relay agent."
If DHCP snooping supports Option 82, it handles clients' requests according to Option 82, if any.
5 describes 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 5 Handling strategies of DHCP snooping
If a DHCP request
has...
Option 82
Untrusted port
GigabitEthernet 1/0/1
GigabitEthernet 1/0/3 and
GigabitEthernet 1/0/4
GigabitEthernet 1/0/1
Handling
strategy
Drop
Keep
Trusted port disabled from
recording binding entries
GigabitEthernet 1/0/3
GigabitEthernet 1/0/1
GigabitEthernet 1/0/3 and
GigabitEthernet 1/0/4
Padding format The DHCP snooping device will...
N/A Drop the message.
Forward the message without changing Option
Random
82.
74
Trusted port enabled to
record binding entries
GigabitEthernet 1/0/2
GigabitEthernet 1/0/2
GigabitEthernet 1/0/2
"Configuring the DHCP
Table