Command Line Reference Guide

Dynamic Host Configuration Protocol (DHCP) | 453
Command
History
Usage
Information
When enabled the system begins creating entries in the binding table for the specified VLAN(s). Note
that learning only happens if there is a trusted port in the VLAN.
Related
Commands
ip dhcp relay information-option
c e s
Enable Option 82.
Syntax
ip dhcp relay information-option [trust-downstream]
Parameters
Command Modes
CONFIGURATION
Default
Disabled
Command
History
show ip dhcp snooping
c e s
Display the contents of the DHCP binding table or display the interfaces configured with IP Source
Guard.
Syntax
show ip dhcp snooping [binding | source-address-validation]
Parameters
Command Modes
EXEC
EXEC Privilege
Default
None
Command
History
Related
Commands
Version 8.3.1.0 Introduced on E-Series.
Version 7.8.1.0 Introduced on C-Series and S-Series
ip dhcp snooping trust
Configure an interface as trusted.
trust-downstream
Configure the system to trust Option 82 when it is received from the previous-hop
router.
Version 8.3.1.0 Introduced on E-Series.
Version 7.8.1.0 Introduced on C-Series and S-Series
binding
Display the binding table.
source-address-validation
Display the interfaces configured with IP Source Guard.
Version 8.3.1.0 Introduced on E-Series.
Version 7.8.1.0 Introduced on C-Series and S-Series
clear ip dhcp snooping Clear the contents of the DHCP binding table.