Allied Telesis IE340 Series User Manual

C613-50631-01 Rev A Command Reference for IE340 Series 2579
AlliedWare Plus™ Operating System - Version 5.5.3-0.x
DHCP SNOOPING COMMANDS
SERVICE
DHCP-SNOOPING
service dhcp-snooping
Overview Use the service dhcp-snooping command to enable the DHCP snooping service
globally on the switch. As well, you need to enable it on the desired VLANs, using
the ip dhcp snooping command. The switch creates a global DHCP snooping
Access Control list (ACL) the first time you use the ip dhcp snooping command, to
send DHCP packets to the CPU for processing. Note that the switch will forward all
DHCP traffic to the CPU, no matter what VLAN it belongs to.
Alternatively, you can use the service dhcp-snooping per-vlan command instead
of the service dhcp-snooping command. This option only creates ACLs for the
VLANs that you configure with the ip dhcp snooping command. This limits the
amount of DHCP traffic that is forwarded to the CPU. However, using this option
creates 2 ACLs for each VLAN that DHCP snooping is enabled on, so it is most
suitable if you have a small number of VLANs. Use the show platform classifier
statistics utilization brief command to see the number of ACLs available for your
switch.
Use the no variant of this command to disable the DHCP snooping service on the
switch.
Syntax
service dhcp-snooping
service dhcp-snooping per-vlan
no service dhcp-snooping
Default Disabled
Mode Global Configuration
Usage notes Enabling DHCP snooping
For DHCP snooping to operate on a VLAN, you must:
• enable the service on the switch by using this command, and
• enable DHCP snooping on the particular VLAN by using the ip dhcp
snooping command, and
• if there is an external DHCP server, configure the port connected to the
server as a trusted port, by using the ip dhcp snooping trust command
Disabling DHCP snooping
Use no service dhcp-snooping to disable DHCP snooping.
Parameter Description
per-vlan This optional parameter only enables DHCP snooping for the
VLANs configured using the command ip dhcp snooping. Using
this option creates ACL entries for only the VLANs that DHCP
snooping is enabled on. This limits the DHCP traffic forwarded to
the CPU.

Allied Telesis IE340 Series Specifications

General

Brand	Allied Telesis
Model	IE340 Series
Category	Switch
Language	English