Cisco Catalyst 4500 Series Command Reference Guide

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Catalyst 4500 Series Switch Cisco IOS Command Reference—Release IOS XE 3.4.0SG and IOS 15.1(2)SG)
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Chapter 2 Cisco IOS Commands for the Catalyst 4500 Series Switches
ip dhcp snooping vlan information option format-type circuit-id string
ip dhcp snooping vlan information option format-type circuit-id
string
To enable circuit-id (a suboption of DHCP snooping option 82) on a VLAN, use the ip dhcp snooping
vlan information option format-type circuit-id string command. To disable circuit-id on a VLAN, use
the no form of this command.
ip dhcp snooping vlan number information option format-type circuit-id [override] string
string
no ip dhcp snooping vlan number information option format-type circuit-id [override] string
Syntax Description
Defaults VLAN-mod-port, if DHCP snooping option-82 is disabled.
Command Modes Interface configuration
Command History
Usage Guidelines The circuit-id suboption of DHCP option 82 is supported only when DHCP snooping is globally enabled
and on VLANs using DHCP option 82.
This command allows you to configure a string of ASCII characters to be the circuit ID. When you want
to override the vlan-mod-port format type and instead use the circuit-ID to define subscriber
information, use the override keyword.
Examples The following example shows how to enable DHCP snooping on VLAN 500 through 555 and option 82
circuit-id:
Switch# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)# ip dhcp snooping
Switch(config)# ip dhcp snooping vlan 500 555
Switch(config)# ip dhcp snooping information option format remote-id string switch123
Switch(config)# interface GigabitEthernet 5/1
Switch(config-if)# ip dhcp snooping trust
Switch(config-if)# ip dhcp snooping limit rate 100
number Specifies single or range of VLANs; valid values are from 1 to 4094.
override (Optional) Specifies an override string.
string string Specifies a user-defined string for the circuit ID; range of 3 to 63 ASCII characters
with no spaces.
Release Modification
12.2(40)SG Support for this command was introduced on the Catalyst 4500 series switch.
12.2(54)SG Added the override option

Cisco Catalyst 4500 Series Specifications

General

Series	Catalyst 4500 Series
Category	Switch
Layer Support	Layer 2, Layer 3
Form Factor	Modular chassis
Stackable	No
Chassis Slots	3, 6, 7, 10
Power Supply Options	AC, DC
Redundancy	Power supply, Supervisor engine
Network Management	Cisco IOS Software CLI, SNMP, Cisco Prime Infrastructure
Features	Security, QoS
Port Density	Up to 384 ports per chassis
Security Features	802.1X, ACLs, DHCP Snooping, Dynamic ARP Inspection, IP Source Guard
Supervisor Engine	8-E