Edge-Core ES3528-WDM

DHCP Snooping Commands
22-9
22
Example
This example enables DHCP snooping globally for the switch.
Related Commands
ip dhcp snooping vlan (22-9)
ip dhcp snooping trust (22-12)
ip dhcp snooping binding (22-10)
ip dhcp snooping vlan
This command enables DHCP snooping on the specified VLAN. Use the no form to
restore the default setting.
Syntax
[no] ip dhcp snooping vlan vlan-id
vlan-id - ID of a configured VLAN (Range: 1-4093)
Default Setting
Disabled
Command Mode
Global Configuration
Command Usage
• When DHCP snooping enabled globally using the ip dhcp snooping
command (page 22-7), and enabled on a VLAN with this command, DHCP
packet filtering will be performed on any untrusted ports within the VLAN as
specified by the ip dhcp snooping trust command (page 22-12).
• When the DHCP snooping is globally disabled, DHCP snooping can still be
configured for specific VLANs, but the changes will not take effect until DHCP
snooping is globally re-enabled.
• When DHCP snooping is globally enabled, configuration changes for specific
VLANs have the following effects:
- If DHCP snooping is disabled on a VLAN, all dynamic bindings learned for
this VLAN are removed from the binding table; all static bindings configured
for this VLAN are retained in the binding table but have no effect.
- If DHCP snooping is re-enabled on a VLAN, any previously configured
static bindings stored in the binding table will take effect again.
Example
This example enables DHCP snooping for VLAN 1.
Console(config)#ip dhcp snooping
Console(config)#
Console(config)#ip dhcp snooping vlan 1
Console(config)#