Quick Reference Guide

182 DHCP Snooping
Example
The following example configures the switch to verify on an untrusted port that the source MAC address
in a DHCP packet matches the client hardware address.
ip dhcp snooping database
The ip dhcp snooping database Global Configuration mode command configures the DHCP snooping
binding file. Use the no form of this command to delete the binding file.
Syntax
• ip dhcp snooping database
• no ip dhcp snooping database
Default Configuration
The URL is not defined.
Command Mode
Global Configuration mode.
User Guidelines
• To ensure that the lease time in the database is accurate, Simple Network Time Protocol (SNTP) is
enabled and configured.
• The switch writes binding changes to the binding file only when the switch system clock is
synchronized with SNTP.
Example
The following example configures the DHCP snooping binding file.
ip dhcp snooping database update-freq
The ip dhcp snooping database update-freq Global Configuration mode command configures the update
frequency ofthe DHCP snooping binding file. Use the no form of this command to return to default.
Syntax
• ip dhcp snooping database update-freq seconds
• no ip dhcp snooping database update-freq
• seconds — Specify, in seconds, the update frequency.
console (config)# ip dhcp snooping verify
console (config)# ip dhcp snooping database
5400_CLI.book Page 182 Wednesday, December 17, 2008 4:33 PM