Ip Dhcp Snooping Database Flash; Ip Dhcp Snooping Trust - Edge-Core ES3528-WDM Management Manual

22
Client Security Commands

ip dhcp snooping database flash

This command writes all dynamically learned snooping entries to flash memory.
Command Mode
Global Configuration
Command Usage
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.
Example
Console(config)#ip dhcp snooping database flash
Console(config)#

ip dhcp snooping trust

This command configures the specified interface as trusted. Use the no form to
restore the default setting.
Syntax
[no] ip dhcp snooping trust
Default Setting
All interfaces are untrusted
Command Mode
Interface Configuration (Ethernet, Port Channel)
Command Usage
• An untrusted interface is an interface that is configured to receive messages
from outside the network or firewall. A trusted interface is an interface that is
configured to receive only messages from within the network.
• When DHCP snooping enabled globally using the ip dhcp snooping
command (page 22-7), and enabled on a VLAN with this 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. All static bindings
are retained, but will have no effect unless the port is changed back to the
untrusted state.
• 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.
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