Service Manual

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.
clear ip dhcp snooping
Clear the DHCP binding table.
Syntax
clear ip dhcp snooping binding
Defaults none
Command Modes EXEC Privilege
Command History
Version Description
9.9(0.0) Introduced on the FN IOM.
8.3.16.1 Introduced on the MXL 10/40GbE Switch IO Module.
Related Commands show ip dhcp snooping — displays the contents of the DHCP binding table.
ip dhcp relay
Enable Option 82.
Syntax
ip dhcp relay information-option [trust-downstream]
Parameters
trust-downstream Configure the system to trust Option 82 when it is received from the previous-hop
router.
Defaults Disabled.
Command Modes CONFIGURATION
Command History
Version Description
9.9(0.0) Introduced on the FN IOM.
8.3.16.1 Introduced on the MXL 10/40GbE Switch IO Module.
ip dhcp snooping
Enable DHCP Snooping globally.
Syntax
[no] ip dhcp snooping
Defaults Disabled.
Command Modes CONFIGURATION
Security 1117