Digisol DG-FS4528P, Management Manual

Page: 632 / 973

C
HAPTER
26 | General Security Measures
DHCP Snooping
– 632 –
command, DHCP packet filtering will be performed on any untrusted
ports within the VLAN according to the default status, or as specifically
configured for an interface with the no ip dhcp snooping trust
command.
When an untrusted port is changed to a trusted port, all the dynamic
DHCP snooping bindings associated with this port are removed.
Additional considerations when the switch itself is a DHCP client – The
port(s) through which it submits a client request to the DHCP server
must be configured as trusted.
E
XAMPLE
This example sets port 5 to untrusted.
Console(config)#interface ethernet 1/5
Console(config-if)#no ip dhcp snooping trust
Console(config-if)#
R
ELATED
C
OMMANDS
ip dhcp snooping (625)
ip dhcp snooping vlan (630)
clear ip dhcp
snooping database
flash
This command removes all dynamically learned snooping entries from flash
memory.
C
OMMAND
M
ODE
Privileged Exec
E
XAMPLE
Console(config)#ip dhcp snooping database flash
Console(config)#
ip dhcp snooping
database flash
This command writes all dynamically learned snooping entries to flash
memory.
C
OMMAND
M
ODE
Privileged Exec
C
OMMAND
U
SAGE
This command can be used to store the currently learned dynamic DHCP
snooping entries to flash memory. These entries will be restored to the
snooping table when the switch is reset. However, note that the lease time
shown for a dynamic entry that has been restored from flash memory will
no longer be valid.