Guest

Cisco Catalyst 2900 XL Series Switches

Catalyst 2900XL/3500XL Switch FAQ

Document ID: 17068

Updated: Sep 25, 2008

   Print

Introduction

This document provides answers to frequently asked questions about the Cisco Catalyst 2900XL/3500XL Series switch.

Prerequisites

Requirements

There are no specific requirements for this document.

Conventions

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

FAQs

Is the port administratively disabled?

Make sure that the "Port Mode" LED indicates STAT mode. If it does not, use the Mode button to cycle through the modes, and set the mode to STAT. If the "Port Status" LED is now amber (does not flash or alternate with green), the port is not forwarding and can be disabled.

  • In order to verify that the port is administratively disabled from the Cisco IOS® command-line interface, use the show interfaces f0/[y] command, where y is the port number. If the first line of output that begins FastEthernet0/[y] is administratively down, the port is administratively disabled.

  • In order to verify that the port is administratively disabled with Switch Manager, click the image of the problem port on the Basic System Configuration page. This displays the Port Management page. For the problem port, check the "Status: Admin/Actual" column. If the Enable box is not checked and it says ADMINDOWN, the port is administratively disabled.

What are the proper cables for this product?

  • 10/100 port - straight through the RJ-45 cable to a router or workstation, or an Ethernet crossover RJ-45 cable to a hub or another switch (Category 5 UTP)

  • 100BaseFX port - multimode fiber with a MIC connector (for connections up to 2 km long), or singlemode fiber with an ST connector (for connections longer than 2 km)

How do I enable the port module?

  • If you use the Cisco IOS command-line interface, use the no shutdown command in interface configuration mode.

  • If you use Switch Manager, click the image of the problem port on the Basic System Configuration page. This displays the Port Management page. For the problem port, check the Enable box in the "Status: Admin/Actual" column.

How do I determine if an IP address is configured on the switch?

From the Cisco IOS command-line interface, do this:

  1. Use the enable command to enter privileged EXEC mode.

  2. Use the show running-config command.

  3. The current IP address for the domain is on the line that begins "ip address" (right under the line that reads "interface VLAN1").

From the Switch Manager, the current IP address for the domain of the switch is the URL in your browser (everything after "http://").

How do I configure an IP address?

You cannot change the IP address in Switch Manager.

  1. From the command line, use the enable command to enter privileged EXEC mode.

  2. Use the configure terminal to enter configuration mode.

  3. Enter interface vlan1 to choose the switch interface for configuration.

  4. Use the command ip address [ip_address] [subnet_mask].

How do I check the subnet mask on the switch and reconfigure it?

If you use Switch Manager to check the subnet mask on the switch, do this:

From the Main menu, choose IP, and the IP Management page displays. The "IP Mask" field contains the current IP subnet mask.

If you use the Cisco IOS line interface, use the enable command to enter privileged EXEC mode. Use the show running-config command to check the subnet mask.

If you use Switch Manager to configure the subnet mask on the switch, enter the subnet mask in the "IP Mask" field. If you use the Cisco IOS line interface, use the configure terminal command to enter configuration mode. Type "interface vlan1" to choose the switch interface for configuration. Use the command ip address [ip_address] [subnet_mask] .

Is there a default route on the switch?

If you use the Cisco IOS command-line interface, use the enable command to enter privileged EXEC mode. Then use the show running-config command and check for a line that begins "ip default-gateway." If you use Switch Manager, choose IP at the Main Menu. The default gateway is shown on the IP Management screen.

How do I set a default route on the switch?

If you use the Cisco IOS command-line interface, use the ip default-gateway [ip_address] command. If you use Switch Manager, choose IP at the Main Menu. You can configure the default gateway on the IP Management screen.

How do I disable auto-negotiation and change the speed and/or duplex settings?

  • If you use Switch Manager, choose PORT from the Main menu to display the Port Management page. You can set the speed and duplex for each port with the pull-down lists in the "Speed" and "Duplex" columns.

  • If you use the Cisco IOS line interface, use the configure terminal command to enter configuration mode. Use the interface [interface] command to choose the switch interface for configuration. In order to set the port speed, use the speed [#] command, where "#" is either "10", "100", or "auto." In order to set the duplex parameter, use the duplex [type] command, where "type" is either "full", "half", or "auto."

What is the procedure so I can retrieve the configuration file from the switch through SNMP?

The only way to retrieve the config file from the switch is to use the Password Recovery procedure. The 3500XL Series switches do not support the procedure to retrieve the configuration through SNMP.

How do I configure voice VLANs?

Cisco Catalyst 2900XL/3500XL switches do not support voice VLANs. These switches support these VLAN post membership modes:

  1. Static-access

  2. Multi-VLAN

  3. Trunk (ISL, Dot1Q, LANE)

  4. Dynamic-access

In order to know more about these post membership modes characteristics, refer to Assigning VLAN Port Membership Modes.

caution Caution: You cannot configure a multi-VLAN port when a trunk is configured on the switch. VLAN traffic on the multi-VLAN port is not encapsulated.

Because the switch does not support voice (auxiliary) VLANs, Cisco recommends IEEE 802.1Q trunk when you connect to Cisco IP phones. By default, a trunk port sends to and receives traffic from all VLANs in the VLAN database. If the switch is configured with a number of VLANs and it is connected to Cisco IP phones through IEEE 802.1Q trunk ports, the switch sends spanning-tree BPDUs for all VLANs to all of the phones. This can flood the phones with traffic, so the allowed VLAN list must include only the VLANs that are necessary on that port, which are usually the voice and data VLANs.

What results if a Catalyst 3550 switch drops the tagged frames or blocks tagged traffic?

The Catalyst 3550 switch does not normally accept 802.1Q tagged frames on access ports. You have to enable features that require these frames to be forwarded, such as QinQ (IEEE 802.1ad or VLAN double tagging or IEEE 802.1q tunneling) or a voice VLAN.

The Catalyst 3750/3560/2970/2960 switches are also normally configured to drop priority tagged frames that are received on access ports unless the QinQ or voice VLAN is configured.

Related Information

Updated: Sep 25, 2008
Document ID: 17068