User guide

216 Brocade 6910 Ethernet Access Switch Configuration Guide
53-1002581-01
DHCP Snooping
10
DHCP Snooping
DHCP snooping allows a switch to protect a network from rogue DHCP servers or other devices
which send port-related information to a DHCP server. This information can be useful in tracking an
IP address back to a physical port. This section describes commands used to configure DHCP
snooping.
ip dhcp snooping
This command enables DHCP snooping globally. Use the no form to restore the default setting.
Syntax
[no] ip dhcp snooping
Default Setting
Disabled
Command Mode
Global Configuration
TABLE 53 DHCP Snooping Commands
Command Function Mode
ip dhcp snooping Enables DHCP snooping globally GC
ip dhcp snooping information
option
Enables or disables the use of DHCP Option 82 information, and
specifies frame format for the remote-id
GC
ip dhcp snooping information
policy
Sets the information option policy for DHCP client packets that
include Option 82 information
GC
ip dhcp snooping verify
mac-address
Verifies the client’s hardware address stored in the DHCP packet
against the source MAC address in the Ethernet header
GC
ip dhcp snooping vlan Enables DHCP snooping on the specified VLAN GC
ip dhcp snooping information
option circuit-id
Enables or disables the use of DHCP Option 82 information circuit-id
suboption
IC
ip dhcp snooping trust Configures the specified interface as trusted IC
clear ip dhcp snooping binding Clears DHCP snooping binding table entries from RAM PE
clear ip dhcp snooping
database flash
Removes all dynamically learned snooping entries from flash
memory.
PE
ip dhcp snooping database
flash
Writes all dynamically learned snooping entries to flash memory GC
show ip dhcp snooping Shows the DHCP snooping configuration settings PE
show ip dhcp snooping
binding
Shows the DHCP snooping binding table entries PE