Table of Contents
Chapter 5: Virtual Local Area Networks.......................................................................................................88
In Depth.................................................................................................................................................88
The Flat Network of Yesterday..............................................................................................................88
Why Use VLANs?.................................................................................................................................89
VLAN Basics..................................................................................................................................90
A Properly Switched Network........................................................................................................90
Switched Internetwork Security......................................................................................................91
Scaling with VLANs..............................................................................................................................92
VLAN Boundaries...........................................................................................................................92
VLAN Membership Types..............................................................................................................93
Traffic Patterns Flowing through the Network...............................................................................93
Cisco’s VLAN Recommendations..................................................................................................93
VLAN Trunking.....................................................................................................................................94
Trunk Types....................................................................................................................................94
LAN Emulation (LANE).................................................................................................................97
VLAN Trunking Protocol (VTP)...........................................................................................................97
VTP Versions..................................................................................................................................98
VTP Advertisements.......................................................................................................................98
VTP Switch Modes.......................................................................................................................100
Methods for VLAN Identification.................................................................................................101
Dynamic Trunking Protocol..........................................................................................................101
InterVLAN Routing.............................................................................................................................101
Internal Route Processors..............................................................................................................102
How InterVLAN Routing Works..................................................................................................102
Configuring a Static VLAN on a Catalyst 5000 Series Switch...........................................................103
Configuring Multiple VLANs on a Catalyst 5000 Series Switch........................................................103
Creating VLANs on a Catalyst 1900EN Series...................................................................................103
Assigning a Static VLAN to an Interface on a 1900EN Series...........................................................104
Viewing the VLAN Configuration on a 1900 Series...........................................................................105
Viewing an Individual VLAN Configuration on a 1900 Series..........................................................105
Configuring a Trunk Port on a Cisco 5000 Series...............................................................................105
Mapping VLANs to a Trunk Port........................................................................................................107
Configuring a Trunk Port on a Cisco 1900EN Series..........................................................................107
Clearing VLANs from Trunk Links on a Cisco 5000 Series...............................................................107
Clearing VLANs from Trunk Links on a Cisco 1900EN Series.........................................................107
Verifying a Trunk Link Configuration on a 5000 Series.....................................................................108
Verifying a Trunk Link Configuration on a 1900EN Series................................................................108
Configuring the VTP Version on a Catalyst 5000 Switch...................................................................108
Configuring a VTP Domain on a Catalyst 1900 Switch......................................................................109
Setting a VTP Domain Password on a Catalyst Switch.......................................................................109
Configuring a Catalyst 1900 Switch as a VTP Server.........................................................................109
Configuring a Catalyst 1900 Switch as a VTP Client.........................................................................109
Configuring a Catalyst 1900 Switch for Transparent Mode................................................................109
Configuring VTP Pruning on a Catalyst 1900 Switch.........................................................................110
Configuring VTP on a Set/Clear CLI Switch......................................................................................110
Configuring VTP on a 1900 Cisco IOS CLI Switch...........................................................................110
Verifying the VTP Configuration on a Set/Clear CLI.........................................................................111
Displaying VTP Statistics....................................................................................................................111
Configuring VTP Pruning on a Set/Clear CLI Switch........................................................................112
Disabling Pruning for Unwanted VLANs............................................................................................112
Configuring IP InterVLAN Routing on an External Cisco Router......................................................112
Configuring IPX InterVLAN Routing on an External Router.............................................................113
v