Cisco Catalyst 4500 Series Software Configuration Guide

19-5
Catalyst 4500 Series Switch, Cisco IOS Software Configuration Guide - Cisco IOS XE 3.9.xE and IOS 15.2(5)Ex
Chapter 19 Configuring Layer 2 Ethernet Interfaces
Configuring Ethernet Interfaces for Layer 2 Switching
Configuring Ethernet Interfaces for Layer 2 Switching
The following sections describe how to configure Layer 2 switching on a Catalyst 4500 series switch
switch:
• Configuring an Ethernet Interface as a Layer 2 Trunk, page 19-5
• Configuring an Interface as a Layer 2 Access Port, page 19-7
• Clearing Layer 2 Configuration, page 19-8
Configuring an Ethernet Interface as a Layer 2 Trunk
Note The default for Layer 2 interfaces is switchport mode dynamic auto. If the neighboring interface
supports trunking and is configured to trunk mode or dynamic desirable mode, the link becomes a
Layer 2 trunk.
To configure an interface as a Layer 2 trunk, perform this task:
Command Purpose
Step 1
Switch(config)# interface {fastethernet |
gigabitethernet | tengigabitethernet}
slot/port
Specifies the interface to configure.
Step 2
Switch(config-if)# shutdown
(Optional) Shuts down the interface to prevent traffic flow until
configuration is complete.
Step 3
Switch(config-if)# switchport trunk
encapsulation {dot1q | negotiate}
(Optional) Specifies the encapsulation.
Note You must enter this command with the dot1q keyword to
support the switchport mode trunk command, which is
not supported by the default mode (negotiate).
Step 4
Switch(config-if)# switchport mode
{dynamic {auto | desirable} | trunk}
Configures the interface as a Layer 2 trunk. (Required only if the
interface is a Layer 2 access port or to specify the trunking mode.)
Step 5
Switch(config-if)# switchport access vlan
vlan_num
(Optional) Specifies the access VLAN, which is used if the
interface stops trunking. The access VLAN is not used as the
native VLAN.
Note The vlan_num parameter is either a single VLAN number
from 1 to 1005 or a range of VLANs described by two
VLAN numbers, the lesser one first, separated by a dash.
Do not enter any spaces between comma-separated vlan
parameters or in dash-specified ranges.
Step 6
Switch(config-if)# switchport trunk
native vlan vlan_num
For 802.1Q trunks, specifies the native VLAN.
Note If you do not set the native VLAN, the default is used
(VLAN 1).
Step 7
Switch(config-if)# switchport trunk
allowed vlan {add | except | all |
remove}
vlan_num[,vlan_num[,vlan_num[,....]]
(Optional) Configures the list of VLANs allowed on the trunk. All
VLANs are allowed by default. You cannot remove any of the
default VLANs from a trunk.

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