Step
5.
Configure Option 82 in
the
padding format.
6.
Configure
Option 82.
Configuring DHCP snooping entries backup
DHCP snooping entries cannot survive a reboot. If the DHCP snooping device is rebooted, security
modules (such as IP source guard) that use DHCP snooping entries to authenticate users reject requests
from clients until new entries are learned.
The DHCP snooping entries backup feature enables you to store DHCP snooping entries in a file. When
the DHCP snooping device reboots, it reads DHCP snooping entries from this file.
Command
•
Configure the padding format
for Option 82:
dhcp-snooping information
format { normal |verbose
[ node-identifier { mac |
sysname | user-defined
node-identifier } ] }
•
Configure the code type for the
non-user-defined
circuit ID sub-option:
dhcp-snooping information
circuit-id format-type { ascii |
hex }
•
Configure the code type for the
remote ID sub-option:
dhcp-snooping information
remote-id format-type { ascii |
hex }
•
Configure the padding content
for the circuit ID sub-option:
dhcp-snooping information
[ vlan vlan-id ] circuit-id string
circuit-id
user-defined
•
Configure the padding content
for the remote ID sub-option:
dhcp-snooping information
[ vlan vlan-id ] remote-id string
{ remote-id | sysname }
78
Remarks
Optional.
By default:
•
The padding format for Option
82 is normal.
•
The code type for the circuit ID
sub-option depends on the
padding format of Option 82.
Each field has its own code type.
•
The code type for the remote ID
sub-option is hex.
The remote ID sub-option
configuration and the circuit ID
sub-option code type configuration
apply only to non-user-defined Option
82.
Optional.
By default:
•
The padding content for the circuit
ID sub-option depends on the
padding format of Option 82.
•
The padding content for the
remote ID sub-option depends on
the padding format of Option 82.