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Creating Ethernet VLANs on Catalyst Switches

Document ID: 10023
Introduction Prerequisites Requirements Components Used Related Products Conventions Difference Between CatOS and Cisco IOS System Software Configure the VLAN on Catalyst Switches That Run CatOS Create VLANs and Ports Remove Ports or VLANs Troubleshooting Tips Configure the VLAN on Catalyst 2900XL, 3500XL, 2950, 2970, and 2940 Series Switches Create VLANs and Ports Remove Ports or VLANs Configure a Multi−VLAN Port on Catalyst 2900XL/3500XL Configure the VLAN on Catalyst 3550, 3750, 4500/4000, and 6500/6000 Switches That Run Cisco IOS Software Create VLANs and Ports Assign Multiple Ports to a Single VLAN Remove VLANs Rename VLANs How to Isolate the Communiation Between Two VLANs How to Configure Extended Range VLANs in a Catalyst 6500 Series Switch Troubleshooting Tips Verify Troubleshoot Inconsistent TLB Value Error on IOS Switches Recover the vlan.dat File on IOS Switches Failed to Create VLANs in Extended Range Failed to Configure VLAN from Startup−Config Backup and Restore of vlan.dat on Cisco IOS Switches VLAN Creation Fails with VLAN 1003 parent VLAN missing Error Message Related Information

Introduction
This document provides basic information on how to create VLANs on Catalyst switches that run Catalyst OS (CatOS) and Cisco IOS® System Software. The sample commands for each section use one Catalyst switch from each configuration section.

Prerequisites
Requirements
Cisco recommends that you have knowledge of the information in this section.

VLANs are a mechanism to allow network administrators to create logical broadcast domains that can span across a single switch or multiple switches, regardless of physical proximity. This function is useful to reduce the size of broadcast domains or to allow groups or users to be logically grouped without the need to be physically located in the same place. In order to create VLANs, you must decide how to configure these items: • What VLAN Trunk Protocol (VTP) domain name and VTP mode to use on this switch • Which ports on the switch belong to which VLAN • If you need to have communication between VLANs, or if they are isolated If you require communication between VLANs, you must use a Layer 3 routing device, such as an external Cisco router or an internal router module. Here are examples: ♦ WS−X4232−Layer 3 card for Catalyst 4500/4000 Switches with Supervisor Engine I and Supervisor Engine II ♦ Route Switch Module (RSM) or Route Switch Feature Card (RSFC) for Catalyst 5500/5000 Switches ♦ Multilayer Switch Module (MSM) or Multilayer Switch Feature Card (MSFC) for Catalyst 6500/6000 Switches Some of the switches have built−in support in software and hardware to do inter−VLAN routing. With inter−VLAN routing, no external device, modules, or daughter cards are required. Here are examples of such switches: ♦ Catalyst 3550/3750/6500 with Supervisor Engine 720 ♦ Catalyst 4500/4000 with Supervisor Engine II+, Supervisor Engine III, and Supervisor Engine IV Refer to these documents for more information on inter−VLAN routing configuration on an MSFC, RSM, RSFC, or external router: • Configuring InterVLAN Routing with Catalyst 3750/3560/3550 Series Switches • Configuring InterVLAN Routing on the MSFC section of Configuring InterVLAN Routing • Configuring InterVLAN Routing on the RSM section of Configuring InterVLAN Routing • Configuring InterVLAN Routing on the RSFC • Configuring InterVLAN Routing on an External Cisco Router section of Configuring InterVLAN Routing • Configuring InterVLAN Routing Using an Internal Router (Layer 3 Card) on Catalyst 5500/5000 and 6500/6000 Switches That Run CatOS System Software • Configuring InterVLAN Routing and ISL/802.1Q Trunking on a Catalyst 2900XL/3500XL/2950 Switch Using An External Router Note: This document assumes that you have basic connectivity to the switch, either through the console or through Telnet access. Refer to these documents for more information on how to get basic connectivity to the switches: • Catalyst 6500/6000 Series SwitchesBasic Software Configuration • Catalyst 2900 Series XL SwitchesQuick Start Guide

Components Used
The information in this document is based on these hardware and software versions: • Catalyst 6009 Switch that runs CatOS 5.5(x) software

• Catalyst 3524XL Switch that runs Cisco IOS Software Release 12.0(5.x)XU • Catalyst 4507 Switch with Supervisor Engine IV (WS−X4515) that runs Cisco IOS Software Release 12.1(13)EW1 The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.

Related Products
The information in this document can also be used with these switches: • Catalyst 4500/4000/2948G/2980G/4912G Switches • Catalyst 5000/2926G Series Switches • Catalyst 6500/6000 Series Switches • Catalyst 2900XL/3500XL/2950/3550/3750 Switches

Conventions
Refer to Cisco Technical Tips Conventions for more information on document conventions.

Difference Between CatOS and Cisco IOS System Software
CatOS on the Supervisor Engine and Cisco IOS Software on the MSFC (Hybrid): a CatOS image can be used as the system software to run the Supervisor Engine on Catalyst 6500/6000 Switches. If the optional MSFC is installed, a separate Cisco IOS Software image is used to run the MSFC. Cisco IOS Software on both the Supervisor Engine and MSFC (Native): a single Cisco IOS Software image can be used as the system software to run both the Supervisor Engine and MSFC on Catalyst 6500/6000 Switches. Note: Refer to Comparison of the Cisco Catalyst and Cisco IOS Operating Systems for the Cisco Catalyst 6500 Series Switch for more information.

Configure the VLAN on Catalyst Switches That Run CatOS
Create VLANs and Ports
Complete the steps in this section in order to create a VLAN. Before you can create a VLAN, the switch must be in VTP server mode or VTP transparent mode. If the switch is a VTP server, you must define a VTP domain name before you can add any VLANs. 1. Define a VTP domain name. You must define the VTP domain name regardless of: ♦ The number of switches in the network, whether one or many ♦ Whether you use VTP in order to propagate VLANs to other switches in the network This is the default VTP configuration on the switch:
CatosSwitch> (enable)show vtp domain

0. . there is only a single VLAN for all ports. This VLAN is called default. 3. CatosSwitch> (enable)show vtp domain Domain Name Domain Index VTP Version Local Mode Password −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− −−−−−−−−−−−− −−−−−−−−−−− −−−−−−−−−−− −−−−−−−−−− cisco 1 2 server − Vlan−count Max−vlan−storage Config Revision Notifications −−−−−−−−−− −−−−−−−−−−−−−−−− −−−−−−−−−−−−−−− −−−−−−−−−−−−− 5 1023 1 disabled Last Updater V2 Mode Pruning PruneEligible on Vlans −−−−−−−−−−−−−−− −−−−−−−− −−−−−−−− −−−−−−−−−−−−−−−−−−−−−−−−− 0.0.Domain Name Domain Index VTP Version Local Mode Password −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− −−−−−−−−−−−− −−−−−−−−−−− −−−−−−−−−−− −−−−−−−−−− 1 2 server − Vlan−count Max−vlan−storage Config Revision Notifications −−−−−−−−−− −−−−−−−−−−−−−−−− −−−−−−−−−−−−−−− −−−−−−−−−−−−− 5 1023 0 disabled Last Updater V2 Mode Pruning PruneEligible on Vlans −−−−−−−−−−−−−−− −−−−−−−− −−−−−−−− −−−−−−−−−−−−−−−−−−−−−−−−− 0. 2.0.0. By default. CatosSwitch> (enable)set vtp domain ? <name> Domain name CatosSwitch> (enable)set vtp domain cisco ? mode passwd pruning v2 Set Set Set Set VTP VTP VTP VTP mode password pruning version 2 CatosSwitch> (enable)set vtp domain cisco mode ? client server transparent VTP client mode VTP server mode VTP transparent mode CatosSwitch> (enable)set vtp domain cisco mode server VTP domain cisco modified Note: Refer to Understanding VLAN Trunk Protocol (VTP) for more information on VTP. you can use Output Interpreter ( registered customers only) in order to display potential issues and fixes. Issue the show vtp domain command in order to verify the VTP configuration. Issue the show vlan command in order to display the parameters for all configured VLANs in the administrative domain. begin to create VLANs on the switch.0 disabled disabled 2−1000 Note: If you have the output of a show vtp domain command from your Cisco device. You cannot rename or delete VLAN 1. After you set and verify the VTP domain.0 disabled disabled 2−1000 Issue the set vtp command in order to set the domain name and mode.

translation = 1.13) Set vlan commands: −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− set vlan Set vlan information set vlan mapping Map an 802.4294967294.4095 bridge_number = 0x1.0xf.1q vlan to an Ethernet vlan CatosSwitch> (enable)set vlan 2 name cisco_vlan_2 Vlan 2 configuration successful b. fddi.1005 hopcount = 1. Vlans −−−− −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− −−−−−−−−− −−−−−−− −−−−−−−−−−−−−−−−−−−−−−−− 1 default active 5 1/1−2 3/1−48 4/1−16 1002 fddi−default active 6 1003 token−ring−default active 9 1004 fddinet−default active 7 1005 trnet−default active 8 VLAN −−−− 1 1002 1003 1004 1005 VLAN −−−− 1 1002 1003 1004 1005 Type −−−−− enet fddi trcrf fdnet trbrf SAID −−−−−−−−−− 100001 101002 101003 101004 101005 MTU −−−−− 1500 1500 1500 1500 1500 Parent −−−−−− − − − − − RingNo −−−−−− − − − − − BrdgNo −−−−−− − − − − − Stp −−−− − − − − ibm BrdgMode −−−−−−−− − − − − − Trans1 −−−−−− 0 0 0 0 0 Trans2 −−−−−− 0 0 0 0 0 DynCreated −−−−−−−−−− static static static static static RSPAN −−−−−−−− disabled disabled disabled disabled disabled VLAN AREHops STEHops Backup CRF 1q VLAN −−−− −−−−−−− −−−−−−− −−−−−−−−−− −−−−−−− 1003 7 7 off a.3/1−2.. parent = 2.. Issue the set vlan command in order to create VLANs..CatosSwitch> (enable)show vlan VLAN Name Status IfIndex Mod/Ports. CatosSwitch> (enable)set vlan Usage: set vlan <vlan> <mod/port> (An example of mod/port is 1/1. Issue the show vlan command in order to verify the VLAN configuration.2/1−12.community.none) hex_ring_number = 0x1. trbrf) said = 1.4/1−12) set vlan <vlan_num> [name <name>] [type <type>] [state <state>] [pvlan−type <pvlan_type>] [said <said>] [mtu <mtu>] [ring <hex_ring_number>] [decring <decimal_ring_number>] [bridge <bridge_number>] [parent <vlan_num>] [mode <bridge_mode>] [stp <stp_type>] [translation <vlan_num>] [backupcrf <off|on>] [aremaxhop <hopcount>] [stemaxhop <hopcount>] [rspan] (name = 1. . state = (active.. srb) stp = (ieee..isolated. mode = (srt.. auto)... suspend) type = (ethernet. IBM. trcrf.1005. decimal_ring_number = 1.18190 pvlan−type = (primary. mtu = 576.32 characters..0xfff. fddinet.

Vlans −−−− −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− −−−−−−−−− −−−−−−− −−−−−−−−−−−−−−−−−−−− 1 default active 5 1/1−2 3/1−48 4/1−16 2 cisco_vlan_2 active 75 1002 fddi−default active 6 1003 token−ring−default active 9 1004 fddinet−default active 7 1005 trnet−default active 8 VLAN −−−− 1 2 1002 1003 1004 1005 Type −−−−− enet enet fddi trcrf fdnet trbrf SAID −−−−−−−−−− 100001 100002 101002 101003 101004 101005 MTU −−−−− 1500 1500 1500 1500 1500 1500 Parent −−−−−− − − − − − − RingNo −−−−−− − − − − − − BrdgNo −−−−−− − − − − − − Stp −−−− − − − − − IBM BrdgMode −−−−−−−− − − − − − − Trans1 −−−−−− 0 0 0 0 0 0 Trans2 −−−−−− 0 0 0 0 0 0 !−−− Output suppressed. Vlans −−−− −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− −−−−−−−−− −−−−−−− −−−−−−−−−−−−−−−−−−−−−−−− 1 default active 5 1/1−2 3/16−48 4/1−16 2 cisco_vlan_2 active 75 3/1−12 3 VLAN0003 active 76 3/13−15 1002 fddi−default active 6 1003 token−ring−default active 9 . CatosSwitch> (enable)set vlan 2 3/1−12 VLAN 2 modified. VLAN Mod/Ports −−−− −−−−−−−−−−−−−−−−−−−−−−− 2 3/1−12 15/1 Note: You can also create the VLAN and add the ports to that VLAN with all the information in a single command. If you want to add ports to the VLAN. c. if you want to create the third VLAN and then assign ports 3/13 through 3/15 to that VLAN.CatosSwitch> (enable)show vlan VLAN Name Status IfIndex Mod/Ports. Mod/Ports −−−−−−−−−−−−−−−−−−−−−−− 3/13−15 15/1 4. Issue the show vlan command in order to verify the VLAN configuration. issue the set vlan vlan_number mod/ports command. 1 modified. CatosSwitch> (enable)show vlan VLAN Name Status IfIndex Mod/Ports. For example. issue this command: CatosSwitch> (enable)set vlan 3 3/13−15 Vlan VLAN VLAN VLAN −−−− 3 3 configuration successful 3 modified. VLAN 1 modified.

Do you want to continue(y/n) [n]? y Vlan 3 deleted CatosSwitch> (enable)show vlan VLAN Name Status IfIndex Mod/Ports. and the VLAN no longer exists. The switch displays a warning and gives you the opportunity to cancel the current request. The ports are not displayed until you add them back in another VLAN. Issue the clear vlan command in order to delete a VLAN. The ports are deactivated because they remain a part of that VLAN. issue the set vlan vlan_number mod/ports command and place the ports in a different VLAN. Note: Ports 3/13 through 3/15 are not displayed in the output of the show vlan command because the removal of VLAN 3 deactivates these ports. This removal is essentially what happens when you assign a port to any VLAN because all ports initially belong to VLAN 1. Vlans −−−− −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− −−−−−−−−− −−−−−−− −−−−−−−−−−−−−−−−−−−−−−−− 1 default active 5 1/1−2 3/16−48 4/1−16 2 cisco_vlan_2 active 75 3/1−12 1002 fddi−default active 6 1003 token−ring−default active 9 1004 fddinet−default active 7 1005 trnet−default active 8 VLAN −−−− 1 2 1002 1003 1004 1005 Type −−−−− enet enet fddi trcrf fdnet trbrf SAID −−−−−−−−−− 100001 100002 101002 101003 101004 101005 MTU −−−−− 1500 1500 1500 1500 1500 1500 Parent −−−−−− − − − − − − RingNo −−−−−− − − − − − − BrdgNo −−−−−− − − − − − − Stp −−−− − − − − − IBM BrdgMode −−−−−−−− − − − − − − Trans1 −−−−−− 0 0 0 0 0 0 Trans2 −−−−−− 0 0 0 0 0 0 !−−− Output suppressed. .1004 fddinet−default 1005 trnet−default VLAN −−−− 1 2 3 1002 1003 1004 1005 Type −−−−− enet enet enet fddi trcrf fdnet trbrf SAID −−−−−−−−−− 100001 100002 100003 101002 101003 101004 101005 MTU −−−−− 1500 1500 1500 1500 1500 1500 1500 Parent −−−−−− − − − − − − − active active RingNo −−−−−− − − − − − − − BrdgNo −−−−−− − − − − − − − 7 8 Stp −−−− − − − − − − IBM BrdgMode −−−−−−−− − − − − − − − Trans1 −−−−−− 0 0 0 0 0 0 0 Trans2 −−−−−− 0 0 0 0 0 0 0 !−−− Output suppressed. CatosSwitch> (enable)clear vlan 3 This command will deactivate all ports on vlan 3 in the entire management domain. Remove Ports or VLANs In order to remove ports from a VLAN.

This state means that the VLAN to which the ports originally belonged was deleted. • Ports are in the inactive state in show port mod/port command output. RSFC. The Create VLANs and Ports section provides the procedure. you receive this error message: Cannot add/modify VLANs on a VTP client. • If you create a VLAN on a switch that is in VTP client mode. Note: A switch can only create VLANs if it is in VTP server mode or VTP transparent mode. create a VTP domain name on the switch. VLAN Type SAID MTU Parent RingNo BrdgNo Stp BrdgMode Trans1 Trans2 −−−− −−−−− −−−−−−−−−− −−−−− −−−−−− −−−−−− −−−−−− −−−− −−−−−−−− −−−−−− −−−−−− Unable to access VTP Vlan 2 information. In order to correct this. VLAN AREHops STEHops Backup CRF 1q VLAN −−−− −−−−−−− −−−−−−− −−−−−−−−−− −−−−−−− • The VLAN interfaces created in the routing modules (RSM. Refer to Understanding VLAN Trunk Protocol (VTP) for more information on VTP. you can use Output Interpreter ( registered customers only) in order to display potential issues and fixes.Troubleshooting Tips This section provides troubleshooting tips for common problems that you can encounter while you create VLANs on Catalyst switches that run CatOS: • If you create a VLAN when there is no VTP domain name defined. AuxiliaryVlan AuxVlan−Status PowerAllocated mWatt mA @42V −−−−− −−−−−−−− − − If you have the output of a show−tech support command from your Cisco device. or MSFC) come up only when the corresponding VLAN is available in the switch. Vlans −−−− −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− −−−−−−−−− −−−−−−− −−−−−−−−−−−−−−−−−−−−−−−− Unable to access VTP Vlan 2 information. you receive this error message: Cannot add/modify VLANs on a VTP server without a domain name. VLAN DynCreated RSPAN −−−− −−−−−−−−−− −−−−−−−− Unable to access VTP Vlan 2 information. This is sample show port mod/port command output: CatosSwitch> (enable)show port 3/1 Port Name Status Vlan Duplex Speed Type −−−−− −−−−−−−−−−−−−−−−−− −−−−−−−−−− −−−−−−−−−− −−−−−− −−−−− −−−−−−−−−−−− 3/1 inactive 2 auto auto 10/100BaseTX Port InlinePowered Admin Oper Detected −−−−− −−−−−−−−−−−−− −−−−−−−−−−−−−− −−−−− −−−−−− −−−−−−−− 3/1 none none − − − !−−− Output suppressed. You can either recreate that VLAN or correct the VTP configuration so that the VLAN is reestablished in the VTP domain. usually because of VTP. MSM. CatosSwitch> (enable)show vlan 2 VLAN Name Status IfIndex Mod/Ports. In order for the VLAN interface to be fully .

After you set and verify the VTP domain. Fa0/20. there is only a single VLAN for all ports. you can make configuration changes centrally on a single switch. Issue the show vlan command in order to check the VLAN information. VTP Domain Name : VTP Pruning Mode : Disabled VTP V2 Mode : Disabled VTP Traps Generation : Disabled MD5 digest : 0xBF 0x86 0x94 0x45 0xFC 0xDF 0xB5 0x70 Configuration last modified by 0. You cannot rename or delete VLAN 1. Fa0/15. Fa0/21. Fa0/10. Fa0/4. This VLAN is called default. Note: Issue the show vtp status command in order to check the VTP status on XL Series Switches. Configure the VLAN on Catalyst 2900XL. make sure to have at least one port as a member of that VLAN. Fa0/18. Fa0/3. and you can automatically communicate those changes to all the other switches in the network. Gi0/1. By default. 2950.0. 3524XL#show vlan VLAN Name Status Ports −−−− −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− −−−−−−−−− −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− 1 default active Fa0/1. Fa0/17. Fa0/12. Gi0/2 1002 fddi−default active . Fa0/24. Fa0/16. 3524XL#show vtp status VTP Version Configuration Revision Maximum VLANs supported locally Number of existing VLANs VTP Operating Mode !−−− This is the default mode. Fa0/9.0.active.0 at 0−0−00 00:00:00 : : : : : 2 0 254 5 Server 2. Fa0/22. Fa0/23. Fa0/2. Refer to Understanding VLAN Trunk Protocol (VTP) for more information on VTP. See the Requirements section of this document for configuration guidelines. 3500XL. Fa0/7. 2950. 2970. begin to create VLANs on the switch. The difference depends on the model of your switch. and 2940 Switches is the server mode. Fa0/14. With VTP. Fa0/13. Fa0/19. Fa0/8. and 2940 Series Switches Create VLANs and Ports Note: The output that you see can be different from some of the command output that this section displays. 3500XL. with an active device connected to the port. Fa0/11. Decide whether to use VTP in your network. Complete these steps in order to create a VLAN. 1. The default VTP mode on the Catalyst 2900XL. which means that it is administratively up and line protocol is up. Fa0/5. 2970. Fa0/6.

!−−− You can skip this command if the switch is already in server mode and you !−−− want the switch to be in server mode. Note: A switch can only create VLANs if it is in VTP server mode or VTP transparent mode. 3524XL(vlan)#vtp server Device mode already VTP SERVER. 524XL(vlan)#vlan ? <1−1005> ISL VLAN index 3524XL(vlan)#vlan 2 ? are backupcrf bridge media mtu name parent ring said state ste stp tb−vlan1 tb−vlan2 Maximum number of All Route Explorer hops for this VLAN Backup CRF mode of the VLAN Bridging characteristics of the VLAN Media type of the VLAN VLAN Maximum Transmission Unit Ascii name of the VLAN ID number of the Parent VLAN of FDDI or Token Ring type VLANs Ring number of FDDI or Token Ring type VLANs IEEE 802.10 SAID Operational state of the VLAN Maximum number of Spanning Tree Explorer hops for this VLAN Spanning tree characteristics of the VLAN ID number of the first translational VLAN for this VLAN (or zero if none) ID number of the second translational VLAN for this VLAN (or zero if none) 3524XL(vlan)#vlan 2 name ? WORD The ASCII name for the VLAN 3524XL(vlan)#vlan 2 name cisco_vlan_2 VLAN 2 added: Name: cisco_vlan_2 3524XL(vlan)#exit !−−− You must exit from the VLAN database in order for the changes !−−− to be committed.1003 token−ring−default 1004 fddinet−default 1005 trnet−default VLAN −−−− 1 1002 1003 1004 1005 Type −−−−− enet fddi tr fdnet trnet SAID −−−−−−−−−− 100001 101002 101003 101004 101005 MTU −−−−− 1500 1500 1500 1500 1500 Parent −−−−−− − − 1005 − − active active active RingNo −−−−−− − − 0 − − BridgeNo −−−−−−−− − − − 1 1 Stp −−−− − − − IBM IBM BrdgMode −−−−−−−− − − srb − − Trans1 −−−−−− 1002 1 1 0 0 Trans2 −−−−−− 1003 1003 1002 0 0 Issue this set of commands in privileged mode in order to create another VLAN: 3524XL#vlan database !−−− You must enter into VLAN database in order to configure any VLAN. . Refer to Understanding VLAN Trunk Protocol (VTP) for more information on VTP.

0. but the switch only supports one active management VLAN interface at a time and other switched virtual interfaces (SVIs) do not up/up because of Layer 2 functionality. Fa0/19.. You can add ports (interfaces) in the newly created VLAN. the switch supports only one active management Layer 3 address. Exiting. Fa0/23. Fa0/14. 3. Fa0/18. Fa0/13. Fa0/22. On a Layer 2 Catalyst Switch. 3524XL#show vlan VLAN Name Status Ports −−−− −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− −−−−−−−−− −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− 1 default active Fa0/1. Fa0/9. Fa0/17. Fa0/16. Switch#configure terminal Switch(config)#interface vlan 2 Switch(config−subif)#management Switch(config−subif)#^Z Switch#show ip interface brief Interface IP−Address VLAN1 10.0. you can issue the optional management command under the new SVI in order to automatically shut down VLAN 1 and transfer the IP address to the new VLAN. You must go to interface configuration mode for each of the interfaces that you want to add into the new VLAN. Fa0/8. Note: You can assign the ports of a Layer 2 Catalyst Switch to multiple VLANs.0. Fa0/4. Therefore. Always check that the switches that run in client mode support the same number of VLANs that the switches in server mode send. Fa0/5.2 VLAN2 20. Fa0/20. Fa0/24. Issue the show vlan command in order to ensure that the VLAN is created.2 FastEthernet0/1 unassigned FastEthernet0/2 unassigned OK? YES YES YES YES Method manual manual unset unset Status up up up up Protocol down up up up .. Fa0/3. Fa0/21. Fa0/6. Fa0/7. 3524XL# Note: The VTP mode can change from client mode to transparent mode if the switch attempts to learn or pass a greater number of VLANs than it supports. Fa0/10. Fa0/2. Fa0/11. Fa0/12. Gi0/1.. Fa0/15.APPLY completed. Gi0/2 2 cisco_vlan_2 active 1002 fddi−default active 1003 token−ring−default active 1004 fddinet−default active 1005 trnet−default active VLAN −−−− 1 2 1002 1003 1004 1005 Type −−−−− enet enet fddi tr fdnet trnet SAID −−−−−−−−−− 100001 100002 101002 101003 101004 101005 MTU −−−−− 1500 1500 1500 1500 1500 1500 Parent −−−−−− − − − 1005 − − RingNo −−−−−− − − − 0 − − BridgeNo −−−−−−−− − − − − 1 1 Stp −−−− − − − − IBM BrdgMode −−−−−−−− − − − srb − Trans1 −−−−−− 1002 0 1 1 0 Trans2 −−−−−− 1003 0 1003 1002 0 4.0.

Fa0/12. Fa0/6. Gi0/1. 5.!−−− Output suppressed. 3524XL#show vlan VLAN Name Status Ports −−−− −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− −−−−−−−−− −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− 1 default active Fa0/1. Building configuration. 3524XL(config−if)#exit 3524XL(config)#interface fastethernet 0/3 3524XL(config−if)#switchport access vlan 2 !−−− These commands assign interface Fast Ethernet 0/3 to VLAN 2. Fa0/15.. Fa0/4. 3524XL(config)#interface fastethernet 0/2 3524XL(config−if)#switchport access ? vlan Set VLAN when interface is in access mode End with CNTL/Z. Fa0/18. Fa0/11. Fa0/24. one per line. Fa0/22. Fa0/10. Fa0/23. Fa0/16. Fa0/13. Issue this set of commands in privileged mode in order to add a particular interface in the VLAN: 3524XL#configure terminal Enter configuration commands. Fa0/17. Fa0/20. Fa0/8. Fa0/21. Fa0/3 1002 fddi−default active 1003 token−ring−default active 1004 fddinet−default active 1005 trnet−default active VLAN −−−− 1 2 Type −−−−− enet enet SAID −−−−−−−−−− 100001 100002 MTU −−−−− 1500 1500 Parent −−−−−− − − RingNo −−−−−− − − BridgeNo −−−−−−−− − − Stp −−−− − − BrdgMode −−−−−−−− − − Trans1 −−−−−− 1002 0 Trans2 −−−−−− 1003 0 . this interfaces VLAN is controlled by VMPS 3524XL(config−if)#switchport access vlan 2 !−−− These commands assign interface Fast Ethernet 0/2 to VLAN 2. Fa0/14.. Fa0/9. 3524XL(config−if)#switchport access vlan ? <1−1001> dynamic VLAN ID of the VLAN when this port is in access mode When in access mode. Fa0/5. Gi0/2 2 cisco_vlan_2 active Fa0/2. 3524XL(config−if)#end 3524XL# 00:55:26: %SYS−5−CONFIG_I: Configured from console by console 3524XL#write memory !−−− This saves the configuration. Fa0/19. Issue the show vlan command in order to verify the VLAN configuration. Fa0/7.

Fa0/10. Fa0/19. For example. Fa0/9. issue the no switchport access vlan vlan_number command in interface configuration mode. if you want to remove interface Fast Ethernet 0/2 from cisco_vlan_2 (VLAN 2). if you want to delete cisco_vlan_2 from the switch. 2 1002 1003 1004 1005 VLAN −−−− 1 2 1002 1003 1004 1005 cisco_vlan_2 fddi−default token−ring−default fddinet−default trnet−default Type −−−−− enet enet fddi tr fdnet trnet SAID −−−−−−−−−− 100001 100002 101002 101003 101004 101005 MTU −−−−− 1500 1500 1500 1500 1500 1500 Parent −−−−−− − − − 1005 − − active active active active active RingNo −−−−−− − − − 0 − − BridgeNo −−−−−−−− − − − − 1 1 Stp −−−− − − − − IBM IBM BrdgMode −−−−−−−− − − − srb − − Trans1 −−−−−− 1002 0 1 1 0 0 Trans2 −−−−−− 1003 0 1003 1002 0 0 In order to delete the VLAN. Fa0/15. Interfaces in that VLAN remain a part of that VLAN and are deactivated because they no longer belong to any VLAN. 3524XL(config−if)#end 3524XL#show vlan VLAN Name Status Ports −−−− −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− −−−−−−−−− −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− 1 default active Fa0/1. Gi0/1. Fa0/2.1002 1003 1004 1005 fddi tr fdnet trnet 101002 101003 101004 101005 1500 1500 1500 1500 − 1005 − − − 0 − − − − 1 1 − − IBM IBM − srb − − 1 1 0 0 1003 1002 0 0 Remove Ports or VLANs In order to remove ports from the VLAN. After the port is removed from a VLAN that is not VLAN 1 (the default VLAN). Fa0/13. Fa0/5. Fa0/7. one per line. Gi0/2 Fa0/3 End with CNTL/Z. Fa0/24. Fa0/4. Fa0/6. issue this set of commands in privileged mode: 3524XL#vlan database . Fa0/21. Fa0/22. Fa0/23. Fa0/8. issue this set of commands in privileged mode: 3524XL#configure terminal Enter configuration commands. that port is automatically added back to the default VLAN. issue the no vlan vlan_number command in VLAN database mode. Fa0/17. Fa0/11. Fa0/16. 3524XL(config)#interface fastethernet 0/2 3524XL(config−if)#no switchport access vlan 2 !−−− These two commands remove interface Fast Ethernet 0/2 from VLAN 2. Fa0/18. Fa0/20. Fa0/14. !−−− Note: Fast Ethernet 0/2 is added back to the default VLAN. Fa0/12. For example.

However. 3524XL#show vlan VLAN Name Status Ports −−−− −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− −−−−−−−−− −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− 1 default active Fa0/1.. Configure a Multi−VLAN Port on Catalyst 2900XL/3500XL The multi−VLAN port feature on Catalyst 2900XL/3500XL Switches allows you to configure a single port in two or more VLANs. A multi−VLAN port performs normal switching functions . Refer to the Configuring Layer 3 Interfaces section of Configuring Interface Characteristics for more information on Layer 3 interfaces on Catalyst 3550 Switches. you must ensure that it belongs to some VLAN. Unless you add the port back in another VLAN. Gi0/1. If you have the output of a show−tech support command from your Cisco device. 3524XL(vlan)#exit APPLY completed.. Fa0/9. Fa0/23. Fa0/20. line protocol is down !−−− Output suppressed. Fa0/8. Fa0/5. Fa0/17.. Fa0/12. This feature allows users from different VLANs to access a server or router without the implementation of inter−VLAN routing capability. Note: In the case of Catalyst 3550 Switches. Fa0/4. Gi0/2 1002 fddi−default active 1003 token−ring−default active 1004 fddinet−default active 1005 trnet−default active !−−− Output suppressed. Notice that port Fast Ethernet 0/3 is not displayed in the show vlan command output. you must add interface Fast Ethernet 0/3 to the default VLAN (VLAN 1) in order to make this interface usable. Fa0/15. Exiting. Fa0/21. Fa0/6. In order to make the interface usable. 3524XL#show interfaces fastethernet 0/3 FastEthernet0/3 is down. Fa0/16. The removal of VLAN 2 deactivates this port. Fa0/7. Deleting VLAN 2.. 3524XL(vlan)#no vlan 2 !−−− This command removes the VLAN from the database. Fa0/14.!−−− This command enters you into the VLAN database mode. the port is neither displayed or usable. Fa0/22. you can use Output Interpreter ( registered customers only) in order to display potential issues and fixes. Fa0/13. Fa0/19.. you need to make that interface a Layer 3 interface. Fa0/11. Fa0/2. you can still use the interface without the addition of the interface to a VLAN. Fa0/18. Fa0/24. Fa0/10. In the case in this section of the document.

Fa0/11. and one port of the switch is connected to an external router. 2. 1. three VLANs are created on a Catalyst 3512XL Switch.3 !−−− This command assigns VLANs 1. 6−3512xl#configure terminal Enter configuration commands. No VTP configuration is necessary. Here. Gi0/2 Fa0/2. Fa0/12. This example configures the port that is connected to the router as a multi−VLAN port. Fa0/7. Determine which port to configure as a multi−VLAN port. Fa0/4 Fa0/5 2 3 4 5 6 VLAN0002 VLAN0003 VLAN0004 VLAN0005 VLAN0006 active active active active active In the example. which disables the VTP. Fa0/3. This feature is not supported on Catalyst 4500/4000. 2. 3500XL. and 2940 Series Switches section of this document. Gi0/1. VLAN traffic on the multi−VLAN port is not encapsulated as it is in trunking. Fa0/10. For more information about how to create VLANs and assign ports to VLANs. • The multi−VLAN port feature is supported only on Catalyst 2900XL/3500XL Series Switches.in all of its assigned VLANs. 6−3512xl(config−if)#switchport multi vlan 1. one per line. and 3 to multi−VLAN port Fast Ethernet 0/1. or 6500/6000 Series Switches or any other Catalyst switches.2. Note: These are the limitations to the implementation of multi−VLAN port features: • You cannot configure a multi−VLAN port when a trunk is configured on the switch. 5500/5000. 6−3512xl(config−if)#switchport multi vlan ? LINE add remove VLAN IDs of VLANs to be used in multi−VLAN mode add VLANs to the current list remove VLANs from the current list End with CNTL/Z. 2970. port Fast Ethernet 0/1 is connected to an external router. 6−3512xl(config−if)#^Z 6−3512xl# . see the Configure the VLAN on Catalyst 2900XL. 2950. The switch automatically transitions to VTP transparent mode when the multi−VLAN port feature is enabled. and add assigned VLANs to the multi−VLAN port. 6−3512xl(config)#interface fastethernet 0/1 6−3512xl(config−if)#switchport mode multi !−−− This command changes the port Fast Ethernet 0/1 mode to multi. Fa0/9. 6−3512xl#show vlan VLAN Name Status −−−− −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− −−−−−−−−− 1 default active Ports −−−−−−−−−−−−−−−−−−−−−−−−−−−−− Fa0/1. Configure the Fast Ethernet 0/1 port in multi−VLAN mode. You can connect the multi−VLAN port only to a router or server. Fa0/8. Fa0/6.

Fa0/1 Fa0/12. timeout is 2 seconds: End with CNTL/Z. Fa0/9. Fa0/10. Fa0/2. one per line. Fa0/4 2 VLAN0002 active !−−− Note: Previously. 2. Fa0/3.168. Fa0/8. !−−− Now the port is assigned to multiple VLANs 1. Gi0/2 Fa0/1. Sending 5.1. 6−3512xl#show interface fastethernet 0/1 switchport Name: Fa0/1 Operational Mode: multi !−−− The port is in multi−VLAN mode.1 255.168.0 !−−− The management IP address is assigned to VLAN 1.255. or 3. 100−byte ICMP Echos to 192. Issue the show interface interface_id switchport command and the show vlan command in order to verify the configuration. 6−3512xl(config)#interface vlan 1 6−3512xl(config−if)#ip address 192. and 3. Gi0/1.255. 2. 6−3512xl(config−if)#^Z 6−3512xl# 23:56:54: %SYS−5−CONFIG_I: Configured from console by console 6−3512xl#ping 192.1. Fa0/6.1 Type escape sequence to abort. Fa0/7. . port Fast Ethernet 0/1 was only in VLAN 1.3.168. The ping command receives a reply from the router each time the management IP address is assigned to any of the VLANs 1. Issue the ping command from the switch to the router in order to verify the multi−VLAN operation.1. 3 4 5 VLAN0003 VLAN0004 VLAN0005 active active active Fa0/1.1. Fa0/5 4. Administrative Trunking Encapsulation: isl Operational Trunking Encapsulation: isl Negotiation of Trunking: Disabled Access Mode VLAN: 0 ((Inactive)) Trunking Native Mode VLAN: 1 (default) Trunking VLANs Enabled: NONE Pruning VLANs Enabled: NONE Priority for untagged frames: 0 Override vlan tag priority: FALSE Voice VLAN: none Appliance trust: none 6−3512xl#show vlan brief VLAN Name Status −−−− −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− −−−−−−−−− 1 default active Ports −−−−−−−−−−−−−−−−−−−−−−−−−−−− Fa0/1. 6−3512xl#configure terminal Enter configuration commands.

2 !−−− You can ping the router from VLAN 1.2.255.1. round−trip min/avg/max = 1/1/3 ms 6−3512xl#ping 192. round−trip min/avg/max = 1/1/3 ms 6−3512xl#configure terminal Enter configuration commands.1 Type escape sequence to abort.168.!!!!! Success rate is 100 percent (5/5).168. 6−3512xl(config)#interface vlan 2 6−3512xl(config−subif)#no ip address !−−− The management IP address is removed from VLAN 2. 6−3512xl(config−if)#shutdown 6−3512xl(config−if)#exit 6−3512xl(config)#interface vlan 2 6−3512xl(config−subif)#ip address 192.1.1 255. timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5). one per line. .168. timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5).2 !−−− You can ping the router from VLAN 2. one per line.168. Sending 5. 100−byte ICMP Echos to 192. round−trip min/avg/max = 1/202/1004 ms 6−3512xl#configure terminal Enter configuration commands. Type escape sequence to abort. End with CNTL/Z. 6−3512xl(config−subif)#exit 6−3512xl(config)#exit 6−3512xl#ping 192.2.1.255. Type escape sequence to abort.168. timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5).1. round−trip min/avg/max = 1/2/3 ms 6−3512xl#ping 192.1. 100−byte ICMP Echos to 192.1. Sending 5. 100−byte ICMP Echos to 192.1.1. 6−3512xl(config−subif)#shutdown End with CNTL/Z. Sending 5.168. 6−3512xl(config)#interface vlan 1 6−3512xl(config−if)#no ip address !−−− The management IP address is removed from VLAN 1.0 6−3512xl(config−subif)#no shutdown !−−− The management IP address is assigned to VLAN 2.168.

The VTP mode must be set to transparent in order to create these VLANs. 3570. the switch must be in VTP server mode or VTP transparent mode.168. and 6500 Series Switches that run Cisco IOS Software.255.168.dat file in Catalyst 4000 Switches with Supervisor Engine IV is the cat4000_flash directory.1. you must define a VTP domain name before you add any VLANs. 6−3512xl(config−subif)#exit 6−3512xl(config)#exit 6−3512xl#ping 192. Switch#dir cat4000_flash: . 100−byte ICMP Echos to 192.2. The default location of the VLAN . Furthermore. Refer to the LAN Product Support Pages in order to locate the Software Configuration Guide.1.168.1. timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5).0 6−3512xl(config−subif)#no shut !−−− The management IP address is assigned to VLAN 3. whether one or many • Whether you use VTP in order to propagate VLANs to other switches in the network Refer to Understanding and Configuring VTP for more information on how to configure VTP on Catalyst 4500/4000 Cisco IOS Software−based Supervisor Engine modules. 3750. Sending 5. VLANs that are numbered higher than 1005 are not advertised by VTP. Before you can create a VLAN. but the configuration tasks also apply to other switches that run Layer 3 (or Cisco IOS Software).1.dat file. You must define a VTP domain name regardless of: • The number of switches in the network. Sending 5. These other switches include the Catalyst 3550.168. You can create VLANs in either VLAN database mode or global configuration mode. Type escape sequence to abort. Refer to the Software Configuration Guide for the switch platform under consideration for VTP configuration information for other Catalyst switch platforms.1 Type escape sequence to abort.1 255.6−3512xl(config−subif)#exit 6−3512xl(config)#interface vlan 3 6−3512xl(config−subif)#ip address 192. round−trip min/avg/max = 1/205/1004 ms Configure the VLAN on Catalyst 3550.2 !−−− You can ping the router from VLAN 3. 4500/4000. You must create VLANs that are numbered higher than 1005 in global configuration mode. round−trip min/avg/max = 1/1/3 ms 6−3512xl#ping 192. 100−byte ICMP Echos to 192.1.255. timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5). If the switch is a VTP server. VLANs that are numbered higher than 1005 are stored in the switch configuration file and not in the VLAN .168.1. and 6500/6000 Switches That Run Cisco IOS Software Create VLANs and Ports This section uses the Catalyst 4500 Switch for sample configuration commands.

either database mode or global configuration mode. Switch#show vtp status VTP Version : 2 Configuration Revision : 0 Maximum VLANs supported locally : 1005 Number of existing VLANs : 8 VTP Operating Mode : Server VTP Domain Name : cisco VTP Pruning Mode : Enabled VTP V2 Mode : Disabled VTP Traps Generation : Disabled MD5 digest : 0xA4 0x18 0x78 0x52 0x5A 0x1B 0x2E 0x14 Configuration last modified by 0.Directory of cat4000_flash:/ 1 −rw− 676 <no date> vlan. Gi3/14 Gi3/15. Gi3/8. Gi3/4. Switch#vlan database . Gi3/16. Enter the correct mode. Gi3/17. Gi3/18 !−−− Output suppressed. Gi3/2 Gi3/3. Switch#show vlan VLAN Name Status Ports −−−− −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− −−−−−−−−− −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− 1 default active Gi1/1. Gi3/10 Gi3/11.10.0.0. Gi3/12. Gi3/1. Gi3/5.0 at 5−28−01 05:17:02 Local updater ID is 10. VLAN −−−− 1002 1003 1004 1005 VLAN −−−− 1 1002 1003 1004 1005 Name −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− fddi−default token−ring−default fddinet−default trnet−default Type −−−−− enet fddi tr fdnet trnet SAID −−−−−−−−−− 100001 101002 101003 101004 101005 MTU −−−−− 1500 1500 1500 1500 1500 Parent −−−−−− − − − − − Status Ports −−−−−−−−− −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− act/unsup act/unsup act/unsup act/unsup BridgeNo −−−−−−−− − − − − − Stp −−−− − − − ieee ibm BrdgMode −−−−−−−− − − − − − Trans1 −−−−−− 0 0 0 0 0 Trans2 −−−−−− 0 0 0 0 0 RingNo −−−−−− − − − − − Primary Secondary Type Ports −−−−−−− −−−−−−−−− −−−−−−−−−−−−−−−−− −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− 2. The show vtp status command shows the VTP information in the switch.dat 524260 bytes total (523584 bytes free) Note: A Catalyst 6500 Switch that runs Cisco IOS Software allows you to create VLANs in server mode without a VTP domain name.10. Gi3/13. Gi3/6 Gi3/7. Issue the vlan database command in privileged mode in order to enter VLAN database mode. Gi3/9. Gi1/2. Issue the show vlan command in order to check the VLAN information.1 on interface Vl1 (lowest numbered VLAN interface) 1.

Switch(vlan)# 3. Issue the exit command in order to exit out of VLAN database mode. Current configuration : 2975 bytes ! version 12. Switch#show running−config Building configuration.. The end keyword and Ctrl−Z exit methods do not work in VLAN database mode. Switch(vlan)#vlan 2 VLAN 2 added: Name: VLAN0002 Switch(vlan)#apply APPLY completed. Note: For the configuration to take effect. .. you can either issue the apply command or exit out of VLAN database mode. Issue the show run command in order to view VLANs that are numbered higher than 1005 in the running configuration. Issue these commands in order to perform the VLAN configuration in global configuration mode: Switch(config)#vlan 3 Switch(config−vlan)#exit Switch(config)# 4. Issue the vlan vlan_number command in order to configure a VLAN.1 no service pad service timestamps debug uptime service timestamps log uptime no service password−encryption service compress−config ! hostname Switch ! ! ip subnet−zero ! spanning−tree extend system−id ! redundancy mode rpr main−cpu auto−sync standard ! ! vlan 2000 ! interface GigabitEthernet1/1 ! interface GigabitEthernet1/2 ! !−−− Output suppressed.

The native VLAN is the VLAN that is used if the interface is to become a Layer 2 interface. Ensure that the trunk ports on both of the connected devices have the same native VLAN. You can configure the interface as a Layer 2 interface with the switchport command in interface configuration mode. The command is useful if the native VLAN of the interface has been changed or needs to be changed from its defaults. among other problems. VLAN 1 becomes the native VLAN by default. the port becomes active if it senses the presence of a physical link. By default. Switch(config−if)#switchport access vlan 2 Switch(config−if)#no shutdown Issue the show interface gigabitethernet module/interface switchport command in order to check the Layer 2 interface status. Cisco IOS Software interfaces are Layer 2 interfaces on Catalyst 3550. In CatOS. this minimum configuration is required: Switch(config)#interface gigabitethernet 3/1 Switch(config−if)#switchport !−−− This command is required if the interface is in Layer 3 mode.1Q header is not added when data are sent on the native VLAN. Note: If the interface is configured as a Layer 3 interface. 3750. In order to associate the ports to VLANs in Cisco IOS Software. The interfaces are Layer 3 interfaces on Catalyst 6500/6000 Series Switches. the switchport trunk native vlan command can be useful. . and 4500 Series Switches. A mismatch in native VLANs can cause inter−VLAN routing issues. Switch#show interface gigabitethernet 3/1 switchport Name: Gi3/1 Switchport: Enabled Administrative Mode: dynamic auto Operational Mode: static access Administrative Trunking Encapsulation: negotiate Operational Trunking Encapsulation: native Negotiation of Trunking: On Access Mode VLAN: 2 (VLAN0002) Trunking Native Mode VLAN: 1 (default) Voice VLAN: none Administrative private−vlan host−association: none Administrative private−vlan mapping: none Administrative private−vlan trunk native VLAN: none Administrative private−vlan trunk encapsulation: dot1q Administrative private−vlan trunk normal VLANs: none Administrative private−vlan trunk private VLANs: none Operational private−vlan: none Trunking VLANs Enabled: ALL Pruning VLANs Enabled: 2−1001 Capture Mode Disabled Capture VLANs Allowed: ALL Voice VLAN: none (Inactive) Appliance trust: none If the port is set up as a trunk. Be aware that an IEEE 802. unlike in CatOS−based switches. which is a port that can carry more than one VLAN. you cannot assign the interface to a VLAN.In Cisco IOS Software. which means that the no switchport command is configured. The command to assign an interface to a VLAN is switchport access vlan vlan_number . if the interface is in Layer 3 mode. You must issue this command before you assign an interface to a VLAN. If you do not explicitly define a native VLAN. interfaces are in the shutdown state by default.

1q trunking 2 Port Vlans allowed on trunk Gi3/1 1−4094 Port Vlans allowed and active in management domain Gi3/1 1−4. Issue the show interfaces module/interface trunk command in order to see the native VLAN. Switch#show interfaces gigabitethernet 3/1 trunk Port Mode Encapsulation Status Native vlan Gi3/1 on 802. Issue these commands: 1. Switch(config)#interface range fastethernet [mod/slot − mod/slot] Switch(config−if−range)#switchport access vlan vlan_number Switch(config−if−range)#switchport mode access Switch(config−if−range)#no shut Note: The interface range command is not supported in all software releases. Switch(config)#interface gigabitethernet 3/1 Switch(config−if)#switchport trunk native vlan 2 Issue this command in order to verify: Switch#show interfaces gigabitethernet 3/1 trunk Port Mode Encapsulation Status Native vlan Gi3/1 on 802.1(13)EW and later. Remove VLANs In order to remove a VLAN from the VLAN database.3000 Port Vlans in spanning tree forwarding state and not pruned Gi3/1 none If you use the default configuration.3000 Port Vlans in spanning tree forwarding state and not pruned Gi3/1 none Assign Multiple Ports to a Single VLAN You can assign the multiple interfaces on a switch to a single VLAN. the native VLAN is VLAN 2 on one of the switches. issue the switchport trunk native vlan vlan_number command. In order to change the native VLAN on the interface that is trunking. This example uses the VLAN database mode to remove . with D−R3550−9B GigabitEthernet0/1 (1) In this example message. encapsulation. and trunking VLAN information. 4. 2. native VLAN is set to VLAN 1.This message appears when the native VLAN is mismatched on the two Cisco switches: %CDP−4−NATIVE_VLAN_MISMATCH: Native VLAN mismatch discovered on GigabitEhernet1/1 (2).2000.2000. but the neighboring switch has native VLAN 1. 3. The interface range command is supported in Cisco IOS Software Release 12.1q trunking 1 Port Vlans allowed on trunk Gi3/1 1−4094 Port Vlans allowed and active in management domain Gi3/1 1−4. issue the no vlan vlan_number command in either VLAN database mode or global configuration mode.

switch#show vlan brief VLAN Name Status Ports −−−− −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− −−−−−−−−− −−−−−−−−−−− 3 CISCO active Fa0/3 Note: When you rename the VLAN. .. you can issue the show vlan command in order to verify the deletion of the VLAN. Private VLANs provide Layer 2 isolation between ports within the same private VLAN (isolated VLAN) or between the private VLANs (community VLANs). one per line.VLAN 2. Switch#vlan database Switch(vlan)#no vlan 2 Deleting VLAN 2.. Switch(vlan)#apply APPLY completed. issue the name vlan_name command in either VLAN database mode or global configuration mode. issue the show vlan brief or show vlan−switch brief command. Switch(vlan)#vlan 3 Switch(vlan)#name CISCO End with CNTL/Z. There are two scenarios for when you try to isolate two VLANs. How to Isolate the Communiation Between Two VLANs This section does not discuss private VLANs. In order to verify. However. This example uses VLAN database mode to rename VLAN 3: Switch#vlan database Switch(vlan)#vlan 3 Switch(vlan)#name CISCO Switch(vlan)#apply APPLY completed. This example uses global configuration mode to rename the VLAN 3: Switch#conf t Enter configuration commands. it is not necessary to remove the VLAN assigned to the port using the switchport access vlan vlan_number command. The global configuration mode does not log any message on the console that indicates the deletion of the VLAN. Rename VLANs In order to rename a VLAN from the VLAN database.

4. The newly created VLAN is VLAN 5. Switch(config)#interface fastEthernet 2/1 Switch(config−if)#switchport mode access Switch(config−if)#switchport access vlan 5 Switch(config−if)#no shut witch(config)#interface fastEthernet 2/2 Switch(config−if)#switchport mode access Switch(config−if)#switchport access vlan 6 Switch(config−if)#no shut 5. Assign to each host a static IP address. ACLs are implemented to deny traffic so that VLAN 1 and VLAN 2 cannot communicate with VLAN 5 and so that VLAN 5 does not communicate either . In this example. You can use ACLs to deny communication between the VLANs. This causes hosts on the ports fa 2/1 and 2/2 to not communicate with each other. Switch#vlan database !−−− You must enter into VLAN database mode in order to !−−− configure any VLAN. 3. This section shows an example of how to isolate the communication between a newly created Layer 3 VLAN and an older VLAN. Devices that belong to one VLAN do not reach anything else but devices within the same VLAN. The new VLAN must appear in the output of the show vlan command. Isolation Between Two Layer 3 VLANs When you create a VLAN and assign an IP address with the interface vlan <vlan_number> command. and do not set a default gateway. Switch(vlan)#vlan 5 VLAN 5 added: Name: VLAN0005 Switch(vlan)#vlan 6 VLAN 6 added: Name: VLAN0006 Switch(vlan)#exit APPLY completed. the VLAN becomes a Layer 3 VLAN. Configure physical interfaces that connect the clients to the corresponding VLAN.. Complete these steps in order to create a Layer 2 VLAN and isolate it from older VLANs: 1. Hosts in the different Layer 2 VLANs cannot communicate with each other. the hosts between the two VLANs can communicate with each other (if the hosts are configured with the default gateway as the VLAN interface IP address). VLAN 1. Exiting. Do not set an IP address to the newly created VLANs. subnet mask. When you exit vlan database mode. Create the new VLAN in the database. In Layer 3 switches. the 3750 switch has two old VLANs (VLAN 1 and VLAN 2). VLAN 2 and VLAN 5 are Layer 3 VLANs. the configuration changes are applied...• Layer 2 VLANs • Layer 3 VLANs Isolation Between Two Layer 2 VLANs A Layer 2 VLAN is the VLAN created in the switch and not configured with the interface vlan <vlan_number> command. Make sure the VLAN is created in the vlan database. 2.

Switch#vlan database !−−− You must enter into VLAN database mode !−−− in order to configure any VLAN.0 0.0 0.0 /24 • VLAN 2 − 172.1. Switch(config)#interface fastEthernet 2/1 Switch(config−if)#switchport mode access Switch(config−if)#switchport access vlan 5 Switch(config−if)#no shut You need to configure three access−lists.0 0.0.0. apply the access lists to interface VLAN 1.0. interface VLAN 2 and interface VLAN 5.1. Make sure the VLAN is created in the vlan database.16.0 0.1. Switch(vlan)#vlan 5 VLAN 5 added: Name: VLAN0005 Switch(vlan)#exit APPLY completed.168.0 Switch(config)#no shut 4.255.16.255 192.168.0.1.0 0.10.168.1. one for each VLAN.1.1.0 0.0 0. 3.255 Switch(config)#access−list 101 permit ip 10..1. Exiting.0 Switch(config)#access−list 102 permit ip 172.0 /24 1. 2. Switch#configure terminal Switch(config)#interface vlan 1 .0. Check the output of the show vlan command.10.0.0 0.0 Switch(config)#access−list 105 deny ip 192.with VLAN 1 or VLAN 2.10. Create the new VLAN in the database. Switch#configure terminal Switch(config)#access−list 102 deny ip 172.1.0 Switch(config)#access−list 105 permit ip 192..168.10.255. !−−− Some of the commands in this output are wrapped !−−− to a second line due to spatial reasons.255 172.1 255.0.1. ♦ This access list denies traffic that comes from VLAN 1 to get to VLAN 5.168. the configuration changes are applied.0.0 0.0.255 192.0.255 any ♦ This access list denies traffic that comes from VLAN 5 to get to VLAN 1 and VLAN 2. Configure physical interfaces that connect the clients to the corresponding VLAN. Switch(config)#interface vlan 5 Switch(config−if)#ip address 192.0.1.0. When you exit vlan database mode.255 any ♦ This access list denies traffic that comes from VLAN 2 to get to VLAN 5.0.10.0 0.0 0.10.255 10.168.10.0 /24 • VLAN 5 − 192.0. Set an IP address for the newly created VLAN.0.0. • VLAN 1 − 10. Switch#configure terminal Switch(config)#access−list 105 deny ip 192.16.255 any And once they are configured.0.0.16..0. In this case the new VLAN is VLAN 5.168. Switch#configure terminal Switch(config)#access−list 101 deny ip 10.10.

Switch#show vlan VLAN Name −−−− −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− 1 default 101 VLAN0101 1002 fddi−default 1003 token−ring−default 1004 fddinet−default 1005 trnet−default 1311 VLAN1311 VLAN Type SAID MTU Status Ports −−−−−−−−− −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− active active Gi4/8. Enter the vtp mode transparent command in configuration mode: Switch(config)#vtp mode transparent 5. Switch(config)# End with CNTL/Z. Gi4/10 act/unsup act/unsup act/unsup act/unsup active BrdgMode Trans1 Trans2 Parent RingNo BridgeNo Stp . Create the VLAN in configuration mode: Switch(config)#vlan 1311 Notice Switch(config−vlan)#exit 6. one per line. Issue the show vlan command in order to check the VLAN information. 3.Switch(config−if)#ip access−group 101 in Switch(config−if)#exit Switch#configure terminal Switch(config)#interface vlan 2 Switch(config−if)#ip access−group 102 in Switch(config−if)#exit Switch#configure terminal Switch(config)#interface vlan 5 Switch(config−if)#ip access−group 105 in Switch(config−if)#end How to Configure Extended Range VLANs in a Catalyst 6500 Series Switch In order to configure extended VLANs on the Catalyst 6500 Series Switches running Cisco IOS. Then the extended VLAN must be created in the configuration mode and not from the vlan database mode. Enter configuration mode: Switch#configure terminal Enter configuration commands. Exit configuration mode: Switch(config)#exit 7. Complete these steps in order to create extended VLANs on the Catalyst 6500 Series Switches that run Cisco IOS: 1. you need to enter the spanning−tree extend system−id command. Enter the spanning−tree extend system−id command in configuration mode: Switch(config)#spanning−tree extended system−id 4. Console into the switch: Switch>enable Switch# 2.

If you copy the configuration from another switch. In order for the SVI to be fully active. a VLAN must be created in VLAN database mode or (in later Cisco IOS Software releases) in global configuration mode. the VLAN database is not copied. Translational VLANs translate Fiber Distributed Data Interface (FDDI) or Token Ring to Ethernet. Troubleshoot Inconsistent TLB Value Error on IOS Switches The inconsistent translational bridging (TLB) value error occurs when you create a VLAN on a Cisco IOS switch that recently received a VTP update from a CatOS switch or which was converted from CatOS. The translation bridge (tb) VLANs for VLAN 1. If the Layer 2 VLAN is not created on the switch. which means that it is administratively up and line protocol is up. make sure to have at least one port as a member of that VLAN.dat). On switches that run Cisco IOS Software. as the procedure in the Create VLANs and Ports section of this document shows. or you must recreate the VLANs. This same issue applies when you copy configurations from a different switch or restore configurations with VLANs that were created in VLAN database mode. it generates this error message: . SVI interfaces show as UP/DOWN in the show ip interface brief command output when the configuration is applied to the switch. Verify There is currently no verification procedure available for this configuration. instead of an external router. You must also replace the VLAN database file (vlan. with an active device connected to the port. Ensure that all previous VLANs that were created in VLAN database mode or global configuration mode still exist after the configuration is copied to the switch. it does not automatically create a VLAN in the Layer 2 database.−−−− 1 101 1002 1003 1004 1005 1311 −−−−− enet enet fddi tr fdnet trnet enet −−−−−−−−−− 100001 100101 101002 101003 101004 101005 101311 −−−−− 1500 1500 1500 1500 1500 1500 1500 −−−−−− − − − − − − − −−−−−− − − − − − − − −−−−−−−− − − − − − − − −−−− − − − − ieee ibm − −−−−−−−− − − − − − − − −−−−−− 0 0 0 0 0 0 0 −−−−−− 0 0 0 0 0 0 0 Troubleshooting Tips This section provides troubleshooting tips for common problems that you can encounter during the creation of VLANs on Catalyst switches that run Cisco IOS Software. This is because CatOS and Cisco IOS have some different default values for translation bridge VLAN. 1002 and 1003 are different in CatOS and are 0 by default . The factory default translation bridge VLANs in Cisco IOS switches are: Vlan ID −−−−−−−− 1 1002 1003 tb1 −−−−− 1002 1 1 tb2 −−−−− 1003 1003 1002 A Cisco IOS switch that recently received a VTP update from a CatOS switch or which was converted from CatOS overwrites the default tb values. you can use the switch itself for interVLAN routing. When you try to create any VLAN after this. In order for an SVI to come up. When an SVI is created.

Issue the show vlan command in order to confirm the availability of VLAN information.dat File on IOS Switches For Cisco Catalyst Switches that run Cisco IOS software.dat file is deleted accidently and the switch gets reloaded. Fa0/11. all the VLANs that were available on the switch are lost. Fa0/4 Fa0/5. Switch#show vlan VLAN Name Status Ports −−−− −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− −−−−−−−−− −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− 1 default active Fa0/1. If the vlan. Fa0/7.. one per line.. make modifications to the VLAN database at any VTP Server of the same domain. the VLAN information is present in the switch. Switch(config)#vlan 50 Switch(config−vlan)#name 50thVLAN Switch(config−vlan)#end Switch# End with CNTL/Z. the VLAN information is on a separate file named vlan. Fa0/3.VLAN 1002 TLB 1 VLAN 1 has inconsistent TLB values (0 / 0) As a workaround for this issue. . switch#vlan data switch(vlan)#no vlan 1002 tb−vlan1 tb−vlan2 switch(vlan)#no vlan 1003 tb−vlan1 tb−vlan2 switch(vlan)#apply APPLY completed. switch(vlan)#exit APPLY completed. ♦ Modify the properties of any existing VLAN. make any modifications to the VLAN database.dat. Modifications to the VLAN database can be any of these: ♦ Create any VLAN. Recover the vlan. change the Cisco IOS switch tb default values for VLAN 1.. 1002 and 1003 to match the CatOS values. If the switch is in VTP Client mode.dat file: 1. Fa0/12. Switch#configure terminal Enter configuration commands. If the switch is in VTP Server or Transparent mode. ♦ Delete any VLAN. Complete these steps in order to recover the vlan. Gi0/1 Gi0/2 10 VLAN0010 active 11 VLAN0011 active 20 VLAN0020 active 21 VLAN0021 active 30 VLAN0030 active 31 VLAN0031 active 40 VLAN0040 active 41 VLAN0041 active 50 Vlan50 active 100 100thVLAN active 2. Fa0/2. Until the switch is reloaded. Fa0/8 Fa0/10.Exiting. Fa0/6.

Issue the show flash: command in order to verify the creation of the vlan.bin vlan.dat file.dat file. You can configure ascending internal VLAN allocation (from 1006 and up) or descending internal VLAN allocation (from 4094 and down). as a workaround. issue the show vlan internal usage command. Note: Switches that run Catalyst product family software do not support the configuration of VLANs 1006−1024.text html c2950−i6q4l2−mz. Layer 3 LAN ports.dat config. which transfers all traffic received in one VLAN to the other VLAN. Switch#show flash: Directory of flash:/ 2 3 4 16 6 7 −rwx −rwx −rwx −rwx drwx −rwx 5 2980487 1156 1014 4096 3121383 Mar Mar Mar Mar Mar Mar 01 02 01 01 02 02 1993 1993 1993 1993 1993 1993 00:04:47 06:08:14 01:51:27 00:04:47 03:49:26 03:47:52 private−config. and some software features. In order to display the VLANs used internally. You cannot use an extended range VLAN that is allocated for internal use. Error 2 %Failed to commit extended VLAN(s) changes .Once any change has been done to the VLAN database. Switch(config)#vlan internal allocation policy {ascending | descending} !−−− Enter the ascending keyword to allocate internal VLANs from 1006 and up. On trunk ports. !−−− Enter the descending keyword to allocate internal VLAN from 4094 and down. The internal VLAN allocation policy is applied only after a reload.text c2950−i6q4l2−mz.EA9. such as RSPAN. If a device reload is not an option. you can translate one VLAN number to another VLAN number.121−22. Refer to the Configuring VLAN Translation section of Configuring VLANs for more information. WAN interfaces and subinterfaces. you can use VLAN Translation. use internal VLANs in the extended range. 3. Switch(config)#end Switch#reload Caution: You do not need to issue the reload command immediately.bin 7741440 bytes total (65536 bytes free) Failed to Create VLANs in Extended Range Error 1 % Failed to create VLANs [dec] VLAN(s) not available in Port Manager.EA1a. Issue the reload command during a planned maintenance window. ensure that the VLANs do not extend to any switches that run Catalyst product family software.121−19. the switch automatically creates the vlan. If you configure VLANs 1006−1024.

dat. Backup and Restore of vlan. complete these steps: 1. In Cisco Catalyst 6500/6000 Series Switches.dat file. If the values do not match. Fallback to use VLAN configuration file from non−volatile memory This message indicates that the VLAN software failed to use the VLAN configuration from the startup configuration file.dat file and the configuration file in order to restore the complete configuration.dat file. Reload the switch. the switch compares the VTP domain name and VTP mode in the startup configuration file and the vlan. In most cases. VLAN Creation Fails with VLAN 1003 parent VLAN missing Error Message Switch#conf t Enter configuration commands. the vlan. Refer to the respective product documentation before issuing the copy command.dat file into the device's NVRAM from a TFTP server or an external PCMCIA card.dat is empty (0). Make sure that the device (Switch or Router) is in Transparent mode when you create extended range VLANs. as vlan. In order to restore the vlan. When the Supervisor module is replaced. Copy the vlan.dat on Cisco IOS Switches In order to backup the vlan. complete this step: Copy the vlan. The network administrator must upload both the vlan. A misconfiguration on a switch can cause the configuration updates of the VTP to fail. The vlan. copy tftp: const_nvram: 2.dat file. vlan. On bootup. it is const_nvram:. Similarily for Catalyst 4500/4000 Switches.dat tftp: Note: The memory location where the vlan.dat file.dat file must be included in the backup with the configuration. Failed to Configure VLAN from Startup−Config SW−VLAN−4−BAD−STARTUP−VLAN−CONFIG−FILE: Failed to configure VLAN from startup−config.dat file is stored varies from device to device. In order to perform a complete backup of your configuration. one per line.dat file from the device's NVRAM to a TFTP server or an external PCMCIA card. the switch uses the configuration in the vlan. Switch(config)#end Switch# End with CNTL/Z.dat is read only during the booting process. it is cat4000_flash:.dat file resides in non−volatile memory. copy const_nvram:vlan.You might receive this message when you are trying to create Extended VLANs in Server or Client mode of VTP. Switch(config)#vlan 102 Switch(config−vlan)#name marketing Switch(config−vlan)#exit VLAN 1003 parent VLAN missing APPLY VLAN changes failed. Refer to the VLAN Trunking Protocol Guidelines section of Extended VLAN ID for more information. The VLAN configuration is stored in the vlan. the problem is that the new VLAN created in the VTP server switch does not propagate to the VTP client .

then the removal of a dummy VLAN on the VTP server. provided that VTP version 2 is disabled on the VTP version 2 capable network device. • Verify that the VTP password is exactly the same on all the switches in the domain. Every network device in the VTP domain must use the same VTP version.1Q Trunking on a Catalyst 2900XL/3500XL/2950 Switch Using an External Router • Cisco IOS Desktop Switching Command Reference. All rights reserved. VTP version 1 and VTP version 2 are not interoperable on the network devices in the same VTP domain. where a VTP client does not update the VLAN information. 5. • Verify that the VTP domain name is exactly the same on the appropriate switches. Related Information • Configuring InterVLAN Routing Using an Internal Router (Layer 3 Card) on Catalyst 5500/5000 and 6500/6000 Switches That Run CatOS System Software • Configuring InterVLAN Routing and ISL/802. Verify the VTP version that runs on a switch. which creates host connectivity issues. Updated: Jul 09. The name is case sensitive. If VTP version 2 is enabled.5 • Understanding VLAN Trunk Protocol (VTP) • LAN Product Support • LAN Switching Technology Support • Technical Support & Documentation − Cisco Systems Contacts & Feedback | Help | Site Map © 2009 − 2010 Cisco Systems.switches. This increments the revision number and forces all VTP clients to update their VLAN database. the workaround is to force a VTP convergence by the creation. If a password is configured. Release 12.0(5)XU • Index − Catalyst 6500 Series Command Reference. VTP version 2 is disabled by default. it must be configured on all switches in the domain and the password must be the same. Verify if the switch is configured properly for other VTP parameters: • Verify that the switches are connected through trunk links. A VTP version 2 capable network device can operate with a network device that runs VTP version 1. In case of a VTP convergence issue. The password is case sensitive. Terms & Conditions | Privacy Statement | Cookie Policy | Trademarks of Cisco Systems. because VTP updates are only exchanged over trunk links. disable it in order to resolve this issue. A common cause for this issue is a VTP version mismatch between the switches in a VTP domain. 2007 Document ID: 10023 . Inc. Inc. The VTP updates are only exchanged between switches in the same VTP domain.