Clear ip dhcp snooping binding, Clear ip dhcp snooping database flash – Brocade Communications Systems Brocate Ethernet Access Switch 6910 User Manual

Page 273

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Brocade 6910 Ethernet Access Switch Configuration Guide

223

53-1002581-01

DHCP Snooping

10

Set all ports connected to DHCP servers within the local network or fire wall to trusted, and all
other ports outside the local network or fire wall to untrusted.

When DHCP snooping is enabled globally using the

ip dhcp snooping

command, and enabled

on a VLAN with

ip dhcp snooping vlan

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.

Example

This example sets port 5 to untrusted.

Console(config)#interface ethernet 1/5

Console(config-if)#no ip dhcp snooping trust

Console(config-if)#

Related Commands

ip dhcp snooping (216)
ip dhcp snooping vlan (220)

clear ip dhcp snooping binding

This command clears DHCP snooping binding table entries from RAM. Use this command without
any optional keywords to clear all entries from the binding table.

Syntax

clear ip dhcp snooping binding [mac-address vlan vlan-id]

mac-address - Specifies a MAC address entry.
(Format: xx-xx-xx-xx-xx-xx)

vlan-id - ID of a configured VLAN (Range: 1-4093)

Command Mode

Privileged Exec

Example

Console(config)#clear ip dhcp snooping binding 11-22-33-44-55-66 vlan 1

Console(config)#

clear ip dhcp snooping database flash

This command removes all dynamically learned snooping entries from flash memory.

Command Mode

Privileged Exec

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