Reference Guide

566 | Security
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Secure DHCP Commands
The dynamic host configuration protocol (DHCP) as defined by RFC 2131 provides no authentication
or security mechanisms. Secure DHCP is a suite of features that protects networks that use dynamic
address allocation from spoofing and attacks. The DHCP commands are:
• clear ip dhcp snooping
• ip dhcp relay
• ip dhcp snooping
• ip dhcp snooping database
• ip dhcp snooping binding
• ip dhcp snooping database renew
• ip dhcp snooping trust
• ip dhcp source-address-validation
• ip dhcp snooping vlan
• show ip dhcp snooping
clear ip dhcp snooping
Clear the DHCP binding table.
Syntax
clear ip dhcp snooping binding
Command Modes
EXEC Privilege
Default
none
Command
History
Related
Commands
ip dhcp relay
Enable Option 82.
Syntax
ip dhcp relay information-option [trust-downstream]
Parameters
Command Modes
CONFIGURATION
Default
Disabled
Command
History
Version 8.3.16.1 Introduced on MXL 10/40GbE Switch IO Module
show ip dhcp snooping Displays the contents of the DHCP binding table.
trust-downstream
Configure the system to trust Option 82 when it is received from the
previous-hop router.
Version 8.3.16.1 Introduced on MXL 10/40GbE Switch IO Module