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Cisco Catalyst 3560 Series Switches

Release Notes for the Catalyst 3750, 3560, and 2970 Switches, Cisco IOS Release 12.2(25)SEB and Later

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Release Notes for the Catalyst 3750, 3560, and 2970 Switches, Cisco IOS Release 12.2(25)SEB and Later

Table Of Contents

Release Notes for the Catalyst 3750, 3560, and 2970 Switches, Cisco IOS Release 12.2(25)SEB and Later

Contents

System Requirements

Hardware Supported

Device Manager System Requirements

Hardware Requirements

Software Requirements

Cluster Compatibility

Upgrading the Switch Software

Finding the Software Version and Feature Set

Deciding Which Files to Use

Upgrading a Switch by Using the Device Manager or Network Assistant

Upgrading a Switch by Using the CLI

Recovering from a Software Failure

Installation Notes

New Features

New Hardware Features

New Software Features

Minimum Cisco IOS Release for Major Features

Limitations and Restrictions

Cisco IOS Limitations

Configuration

Ethernet

Fallback Bridging

HSRP

IP

IP Telephony

Management

MAC Addressing

Multicasting

QoS

Routing

SPAN and RSPAN

Stacking (Catalyst 3750 switch stack only)

Trunking

VLAN

Device Manager Limitations

Important Notes

Switch Stack Notes

Cisco IOS Notes

Device Manager Notes

Open Caveats

Resolved Caveats

Resolved IOS Caveats in Cisco IOS Release 12.2(25)SEB4

Resolved IOS Caveats in Cisco IOS Release 12.2(25)SEB3

Resolved IOS Caveats in Cisco IOS Release 12.2(25)SEB2

Resolved IOS Caveats in Cisco IOS Release 12.2(25)SEB1

Resolved IOS Caveats in Cisco IOS Release 12.2(25)SEB

Documentation Updates in Cisco IOS Release 12.2(25)SEB

Updates to the Software Configuration Guides

Configuring Interface Characteristics for the Catalyst 3750 Switch

Unsupported CLI Commands

Supported MIBs

Port Security Updates

IGMP Updates

QoS Updates

Updates to the Command Reference

clear port-security

ip igmp snooping last-member-query interval

show ip igmp snooping

show version

switchport port-security

Documentation Updates in Cisco IOS Release 12.2(25)SEA

Correction to the Software Configuration Guides

Updates for the Software Configuration Guides

Updates for the Command Reference

Related Documentation

Obtaining Documentation

Cisco.com

Product Documentation DVD

Ordering Documentation

Documentation Feedback

Cisco Product Security Overview

Reporting Security Problems in Cisco Products

Obtaining Technical Assistance

Cisco Technical Support & Documentation Website

Submitting a Service Request

Definitions of Service Request Severity

Obtaining Additional Publications and Information


Release Notes for the Catalyst 3750, 3560, and 2970 Switches, Cisco IOS Release 12.2(25)SEB and Later


Revised November 2, 2005

The Cisco IOS Release 12.2(25)SEB and later run on all Catalyst 3750, 3560, and 2970 switches.

The Catalyst 3750 switches support stacking through Cisco StackWise technology. The Catalyst 3560 and 2970 switches do not support switch stacking. Unless otherwise noted, the term switch refers to a standalone switch and to a switch stack.

These release notes include important information about Cisco IOS Release 12.2(25)SEB, Cisco IOS Release 12.2(25)SEB1, Cisco IOS Release 12.2(25)SEB2, Cisco IOS Release 12.2(25)SEB3, and Cisco IOS Release 12.2(25)SEB4, and any limitations, restrictions, and caveats that apply to them. Verify that these release notes are correct for your switch:

If you are installing a new switch, see the Cisco IOS release label on the rear panel of your switch.

If your switch is on, use the show version privileged EXEC command. See the "Finding the Software Version and Feature Set" section.

If you are upgrading to a new release, see the software upgrade filename for the software version. See the "Deciding Which Files to Use" section.

For the complete list of Catalyst 3750, 3560, and 2970 switch documentation, see the "Related Documentation" section.

You can download the switch software from this site (registered Cisco.com users with a login password):

http://www.cisco.com/kobayashi/sw-center/sw-lan.shtml


Note For IPv6 capability on the Catalyst 3750 or 3560 switches, you must order the advanced IP services image upgrade from Cisco.


This software release is part of a special release of Cisco IOS software that is not released on the same 8-week maintenance cycle that is used for other platforms. As maintenance releases and future software releases become available, they will be posted to Cisco.com in the Cisco IOS software area.

Cisco IOS Release 12.2(25)SEB and later are based on Cisco IOS Release 12.2(25)S. Open caveats in Cisco IOS Release 12.2(25)S also affect Cisco IOS Release 12.2(25)SEB and later, unless they are listed in the Cisco IOS Release 12.2(25)SEB and later resolved caveats list. The list of open caveats in Cisco IOS Release 12.2(25)S is available at this URL:

http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122relnt/122srn.htm#wp2367913

Contents

This information is in the release notes:

"System Requirements" section

"Upgrading the Switch Software" section

"Installation Notes" section

"New Features" section

"Minimum Cisco IOS Release for Major Features" section

"Limitations and Restrictions" section

"Important Notes" section

"Open Caveats" section

"Resolved Caveats" section

"Documentation Updates in Cisco IOS Release 12.2(25)SEB" section

"Documentation Updates in Cisco IOS Release 12.2(25)SEA" section

"Related Documentation" section

"Obtaining Documentation" section

"Documentation Feedback" section

"Cisco Product Security Overview" section

"Obtaining Technical Assistance" section

"Obtaining Additional Publications and Information" section

System Requirements

The system requirements are described in these sections:

"Hardware Supported" section

"Device Manager System Requirements" section

"Cluster Compatibility" section

Hardware Supported

Table 1 lists the hardware supported on Cisco IOS Release 12.2SE.

Table 1 Catalyst 3750, 3560, and 2970 Supported Hardware 

Switch
Description
Supported by Minimum Cisco IOS Release

Catalyst 3750-24FS

24 100BASE-FX ports and 2 SFP1 module slots

Cisco IOS Release 12.2(25)SEB

Catalyst 3750-24PS

24 10/100 PoE2 ports and 2 SFP module slots

Cisco IOS Release 12.2(18)SE

Catalyst 3750-24TS

24 10/100 Ethernet ports and 2 SFP module slots

Cisco IOS Release 12.2(18)SE

Catalyst 3750-48PS

48 10/100 PoE ports and 4 SFP module slots

Cisco IOS Release 12.2(18)SE

Catalyst 3750-48TS

48 10/100 Ethernet ports and 4 SFP module slots

Cisco IOS Release 12.2(18)SE

Catalyst 3750G-12S

12 SFP module slots

Cisco IOS Release 12.2(18)SE

Catalyst 3750G-12S-SD

12 SFP module slots

Cisco IOS Release 12.2(25)SEB

Catalyst 3750G-16TD

16 10/100/1000 Ethernet ports and 1 XENPAK 10-Gigabit Ethernet module slot

Cisco IOS Release 12.2(18)SE

Catalyst 3750G-24PS

24 10/100/1000 PoE ports and 4 SFP module slots

Cisco IOS Release 12.2(20)SE3

Catalyst 3750G-24T

24 10/100/1000 Ethernet ports

Cisco IOS Release 12.2(18)SE

Catalyst 3750G-24TS

24 10/100/1000 Ethernet ports and 4 SFP module slots

Cisco IOS Release 12.2(18)SE

Catalyst 3750G-24TS-1U

24 10/100/1000 Ethernet ports and 4 SFP module slots

Cisco IOS Release 12.2(20)SE3

Catalyst 3750G-48PS

48 10/100/1000 PoE ports and 4 SFP module slots

Cisco IOS Release 12.2(20)SE3

Catalyst 3750G-48TS

48 10/100/1000 Ethernet ports and 4 SFP module slots

Cisco IOS Release 12.2(20)SE3

Catalyst 3560-24PS

24 10/100 PoE ports and 2 SFP module slots

Cisco IOS Release 12.2(18)SE

Catalyst 3560-24TS

24 10/100 ports and 2 SFP module slots

Cisco IOS Release 12.2(20)SE3

Catalyst 3560-48PS

48 10/100 PoE ports and 4 SFP module slots

Cisco IOS Release 12.2(18)SE

Catalyst 3560-48TS

48 10/100 ports and 4 SFP module slots

Cisco IOS Release 12.2(20)SE3

Catalyst 3560G-24PS

24 10/100 PoE ports and 4 SFP module slots

Cisco IOS Release 12.2(20)SE3

Catalyst 3560G-24TS

24 10/100/1000 Ethernet ports and 4 SFP module slots

Cisco IOS Release 12.2(20)SE3

Catalyst 3560G-48PS

48 10/100/1000 PoE ports and 4 SFP module slots

Cisco IOS Release 12.2(20)SE3

Catalyst 3560G-48TS

48 10/100/1000 Ethernet ports and 4 SFP module slots

Cisco IOS Release 12.2(20)SE3

Catalyst 2970G-24T

24 10/100/1000 Ethernet ports

Cisco IOS Release 12.2(18)SE

Catalyst 2970G-24TS

24 10/100/1000 Ethernet ports and 4 SFP module slots

Cisco IOS Release 12.2(18)SE

SFP modules

1000BASE-T, 1000BASE-SX

1000BASE-LX, 1000BASE-ZX, and CWDM3

100BASE-FX MMF4

Cisco IOS Release 12.2(18)SE

Cisco IOS Release 12.2(20)SE

XENPAK modules5

XENPAK-10-GB-ER, XENPAK-10-GB-LR, XENPAK-10-GB-LX4, XENPAK-10-GB-SR, and XENPAK-10-GB-CX4

Cisco IOS Release 12.2(18)SE

Redundant power systems

Cisco RPS 675 Redundant Power System

Supported on all software releases

1 SFP = small form-factor pluggable

2 PoE = Power over Ethernet

3 CWDM = coarse wavelength-division multiplexer

4 MMF = multimode fiber

5 XENPAK modules are only supported on the Catalyst 3750G-16TD switches.


Device Manager System Requirements

These sections describes the hardware and software requirements for using the device manager:

"Hardware Requirements" section

"Software Requirements" section

Hardware Requirements

Table 2 lists the minimum hardware requirements for running the device manager.

Table 2 Minimum Hardware Requirements 

Processor Speed
DRAM
Number of Colors
Resolution
Font Size

Intel Pentium II1

64 MB2

256

1024 x 768

Small

1 We recommend Intel Pentium 4.

2 We recommend 256-MB DRAM.


Software Requirements

Table 3 lists the supported operating systems and browsers for using the device manager. The device manager verifies the browser version when starting a session to ensure that the browser is supported.


Note The device manager does not require a plug-in.


Table 3 Supported Operating Systems and Browsers 

Operating System
Minimum Service Pack or Patch
Microsoft Internet Explorer 1
Netscape Navigator

Windows 98

None

5.5 or 6.0

7.1

Windows NT 4.0

Service Pack 6 or later

5.5 or 6.0

7.1

Windows 2000

None

5.5 or 6.0

7.1

Windows XP

None

5.5 or 6.0

7.1

1 Service Pack 1 or higher is required for Internet Explorer 5.5.


Cluster Compatibility

You cannot create and manage switch clusters through the device manager. To create and manage switch clusters, use the command-line interface (CLI) or the Network Assistant application.

When creating a switch cluster or adding a switch to a cluster, follow these guidelines:

When you create a switch cluster, we recommend configuring the highest-end switch in your cluster as the command switch.

If you are managing the cluster through Network Assistant, the switch with the latest software should be the command switch, unless your command switch is running Cisco IOS Release 12.1(19)EA1 or later.

The standby command switch must be the same type as the command switch. For example, if the command switch is a Catalyst 3750 switch, all standby command switches must be Catalyst 3750 switches.

For additional information about clustering, see Getting Started with Cisco Network Assistant and Release Notes for Cisco Network Assistant (not orderable but available on Cisco.com), the software configuration guide, and the command reference.

Upgrading the Switch Software

These are the procedures for downloading software. Before downloading software, read this section for important information:

"Finding the Software Version and Feature Set" section

"Deciding Which Files to Use" section

"Upgrading a Switch by Using the Device Manager or Network Assistant" section

"Upgrading a Switch by Using the CLI" section

"Recovering from a Software Failure" section

Finding the Software Version and Feature Set

The Cisco IOS image is stored as a bin file in a directory that is named with the Cisco IOS release. A subdirectory contains the files needed for web management. The image is stored on the system board flash device (flash:).

You can use the show version privileged EXEC command to see the software version that is running on your switch. The second line of the display shows the version.


Note For Catalyst 3750 and 3560 switches, although the show version output always shows the software image running on the switch, the model name shown at the end of this display is the factory configuration (IP base image [formerly known as the SMI] or IP services image [formerly known as the EMI]) and does not change if you upgrade the software image.


You can also use the dir filesystem: privileged EXEC command to see the directory names of other software images that you might have stored in flash memory.

Deciding Which Files to Use

The upgrade procedures in these release notes describe how to perform the upgrade by using a combined tar file. This file contains the Cisco IOS image file and the files needed for the embedded device manager. You must use the combined tar file to upgrade the switch through the device manager. To upgrade the switch through the command-line interface (CLI), use the tar file and the archive download-sw privileged EXEC command.

For the Catalyst 3750 and 3560 switches, Cisco IOS Release 12.2(25)SEA and earlier referred to the image that provides Layer 2+ features and basic Layer 3 routing as the standard multilayer image (SMI). The image that provides full Layer 3 routing and advanced services was referred to as the enhanced multilayer image (EMI).

Cisco IOS Release 12.2(25)SEB and later refers to the SMI as the IP base image and the EMI as the IP services image.

Cisco IOS Release 12.2(25)SEB and later refers to the Catalyst 2970 image as the LAN base image.

Table 4 lists the different file-naming conventions before and after Cisco IOS Release 12.2(25)SEB.

Table 4 Cisco IOS Image File Naming Convention

Cisco IOS 12.2(25)SEA and earlier
Cisco IOS 12.2(25)SEB and later

c3750-i9-mz (SMI1 )

c3750-ipbase-mz

c3750-i9k91-mz (SMI)

c3750-ipbasek9-mz

c3750-i5-mz (EMI2 )

c3750-ipservices-mz

c3750-i5k91-mz (EMI)

c3750-ipservicesk9-mz

c3560-i9-mz (SMI)

c3560-ipbase-mz

c3560-i9k91-mz (SMI)

c3560-ipbasek9-mz

c3560-i5-mz (EMI)

c3560-ipservices-mz

c3560-i5k91-mz (EMI)

c3560-ipservicesk9-mz

c2970-i6l2-mz

c2970-lanbase-mz

c2970-i6k91l2-mz

c2970-lanbasek9-mz

1 SMI = standard multilayer image

2 EMI = enhanced multilayer image


Table 5 lists the filenames for this software release.


Note For IPv6 capability on the Catalyst 3750 or 3560, you must order the advanced IP services image upgrade from Cisco.


Table 5 Cisco IOS Software Image Files 

Filename

Description

c3750-ipbase-tar.122-25.SEB4.tar

Catalyst 3750 IP base image and device manager files.
This image has Layer 2+ and basic Layer 3 routing features.

c3750-ipservices-tar.122-25.SEB4.tar

Catalyst 3750 IP services image and device manager files.
This image has both Layer 2+ and full Layer 3 routing features.

c3750-ipbasek9-tar.122-25.SEB4.tar

Catalyst 3750 IP base cryptographic image and device manager files.
This image has the Kerberos, SSH1 , Layer 2+, and basic Layer 3 routing features.

c3750-ipservicesk9-tar.122-25.SEB4.tar

Catalyst 3750 IP services cryptographic image and device manager files.
This image has the Kerberos, SSH, Layer 2+, and full Layer 3 features.

c3750-advipservicesk9-tar.122-25.SEB4.tar

Catalyst 3750 advanced IP services image, cryptographic file, and device manager files.
This image has all the IP services image (formerly known as the EMI) features and the capability for unicast routing of IPv6 packets.

c3560-ipbase-tar.122-25.SEB4.tar

Catalyst 3560 IP base image file and device manager files.
This image has Layer 2+ and basic Layer 3 routing features.

c3560-ipservices-tar.122-25.SEB4.tar

Catalyst 3560 IP services image and device manager files.
This image has both Layer 2+ and full Layer 3 routing features.

c3560-ipbasek9-tar.122-25.SEB4.tar

Catalyst 3560 IP base cryptographic image and device manager files.
This image has the Kerberos, SSH, and Layer 2+, and basic Layer 3 routing features.

c3560-ipservicesk9-tar.122-25.SEB4.tar

Catalyst 3560 IP services cryptographic image and device manager files. This image has the Kerberos, SSH, Layer 2+, and full Layer 3 features.

c3560-advipservicesk9-tar.122-25.SEB4.tar

Catalyst 3560 advanced IP services image, cryptographic file, and device manager files.
This image has all the IP services image (formerly known as the EMI) features and the capability for unicast routing of IPv6 packets.

c2970-lanbase-tar.122-25.SEB4.tar

Catalyst 2970 image file and device manager files.
This image has Layer 2+ features.

c2970-lanbasek9-tar.122-25.SEB4.tar

Catalyst 2970 cryptographic image file and device manager files.
This image has the Kerberos and SSH features.

1 SSH = Secure Shell


Upgrading a Switch by Using the Device Manager or Network Assistant

You can upgrade switch software by using the device manager or Network Assistant. For detailed instructions, click Help.


Note When using the device manager to upgrade your switch, do not use or close your browser session after the upgrade process begins. Wait until after the upgrade process completes.


Upgrading a Switch by Using the CLI

This procedure is for copying the combined tar file to the switch. You copy the file to the switch from a TFTP server and extract the files. You can download an image file and replace or keep the current image.

To download software, follow these steps:


Step 1 Use Table 5 to identify the file that you want to download.

Step 2 Download the software image file. If you have a SmartNet support contract, go to this URL, and log in to download the appropriate files:

http://www.cisco.com/kobayashi/sw-center/sw-lan.shtml

To download the image for a Catalyst 2970 switch, click Catalyst 2970 software. To obtain authorization and to download the cryptographic software files, click Catalyst 2970 3DES Cryptographic Software.

To download the IP services image (formerly known as the EMI) or IP base image (formerly known as the SMI) files for a Catalyst 3560 switch, click Catalyst 3560 software. To obtain authorization and to download the cryptographic software files, click Catalyst 3560 3DES Cryptographic Software.

To download the IP services image (formerly known as the EMI) or IP base image (formerly known as the SMI) files for a Catalyst 3750 switch, click Catalyst 3750 software. To obtain authorization and to download the cryptographic software files, click Catalyst 3750 3DES Cryptographic Software.


Caution If you are upgrading a Catalyst 3750 or a Catalyst 2970 switch that is running a release earlier than Cisco IOS Release 12.1(19)EA1c, this release includes a bootloader upgrade. The bootloader can take up
to 1 minute to upgrade the first time that the new software is loaded. Do not power cycle the switch during the bootloader upgrade.

Step 3 Copy the image to the appropriate TFTP directory on the workstation, and make sure that the TFTP server is properly configured.

For more information, refer to Appendix B in the software configuration guide for this release.

Step 4 Log into the switch through the console port or a Telnet session.

Step 5 (Optional) Ensure that you have IP connectivity to the TFTP server by entering this privileged EXEC command:

Switch# ping tftp-server-address

For more information about assigning an IP address and default gateway to the switch, refer to the software configuration guide for this release.

Step 6 Download the image file from the TFTP server to the switch. If you are installing the same version of software that is currently on the switch, overwrite the current image by entering this privileged EXEC command:

Switch# archive download-sw /overwrite /reload 
tftp:[[//location]/directory]/image-name.tar

The /overwrite option overwrites the software image in flash memory with the downloaded one.

The /reload option reloads the system after downloading the image unless the configuration has been changed and not saved.

For //location, specify the IP address of the TFTP server.

For /directory/image-name.tar, specify the directory (optional) and the image to download. Directory and image names are case sensitive.

This example shows how to download an image from a TFTP server at 198.30.20.19 and to overwrite the image on the switch:

Switch# archive download-sw /overwrite 
tftp://198.30.20.19/c3750-ipservices-tar.122-25.SEB.tar

You can also download the image file from the TFTP server to the switch and keep the current image by replacing the /overwrite option with the /leave-old-sw option.


Recovering from a Software Failure

For recovery procedures, see the "Troubleshooting" chapter in the software configuration guide for this release.

Installation Notes

You can assign IP information to your switch by using these methods:

The Express Setup program, as described in the switch getting started guide.

The CLI-based setup program, as described in the switch hardware installation guide.

The DHCP-based autoconfiguration, as described in the switch software configuration guide.

Manually assigning an IP address, as described in the switch software configuration guide.


Note If you are upgrading a Catalyst 3750 or a 2950 switch running Cisco IOS Release 12.1(11)AX, which uses the IEEE 802.1x feature, you must re-enable IEEE 802.1x after upgrading the software. For more information, see the "Cisco IOS Notes" section.



Note When upgrading or downgrading from Cisco IOS Release 12.2(18)SE, you might need to reconfigure the switch with the same password that you were using when running Cisco IOS Release 12.2(18)SE. This problem only occurs when changing from Cisco IOS Release 12.2(18)SE to any other release. (CSCed88768)


New Features

These sections describe the new supported hardware and the new software features provided in this release:

"New Hardware Features" section

"New Software Features" section

New Hardware Features

There are no new hardware features for this release. For a list of all supported hardware, see the "Hardware Supported" section.

New Software Features

This release contains these new Catalyst 3750, 3560, and 2970 switch features or enhancements (available in all software images):

IGMP leave timer to configure the leave latency for the network.

The Private VLAN feature is now supported by the IP base image (formerly known as the SMI). In previous releases, this feature was only supported by the IP services image (formerly known as the EMI).

This release uses a Cisco IOS image file-naming convention that is different from previous releases. For more information, see Table 4.

This release contains these new Catalyst 3750 and 3560 switch features or enhancements (available in all software images):

IP Source Guard and Dynamic ARP Inspection are now supported by the IP base image (formerly known as the SMI). In previous releases, these features were only supported by the IP services image (formerly known as the EMI).

Minimum Cisco IOS Release for Major Features

Table 6 lists the minimum software release required to support the major features of the Catalyst 3750, 3560, and 2970 switches.

Table 6 Catalyst 3750, 3560, and 2970 Switch Features and the Minimum Cisco IOS Release Required 

Feature
Minimum Cisco IOS Release Required
Catalyst Switch Support

Support for configuring private-VLAN ports on interfaces that are configured for dynamic ARP inspection (IP base image [formerly known as the SMI] only)

12.2(25)SEB

3750, 3560, 2970

Support for IP source guard on private VLANs (IP base image [formerly known as the SMI] only)

12.2(25)SEB

3750 and 3560

IGMP leave timer

12.2(25)SEB

3750, 3560, 2970

IGMP snooping querier

12.2(25)SEA

3750, 3560, 2970

Advanced IP services

12.2(25)SEA

3750, 3560

Support for DSCP transparency

12.2(25)SE

3750, 3560, 2970

Support for VLAN-based QoS1 and hierarchical policy maps on SVIs2

12.2(25)SE

3750, 3560, 2970

Device manager

12.2(25)SE

3750, 3560, 2970

IEEE 802.1Q tunneling and Layer 2 protocol tunneling

12.2(25)SE

3750, 3560

Layer 2 point-to-point tunneling and Layer 2 point-to-point tunneling bypass

12.2(25)SE

3750, 3560

Support for SSL version 3.0 for secure HTTP communication (cryptographic images only)

12.2(25)SE

3750, 3560, 2970

Support for configuring private-VLAN ports on interfaces that are configured for dynamic ARP inspection (IP services image [formerly known as the EMI] only)

12.2(25)SE

3750 and 3560

Support for IP source guard on private VLANs (IP services image [formerly known as the EMI] only)

12.2(25)SE

3750 and 3560

Cisco intelligent power management to limit the power allowed on a port, or pre-allocate (reserve) power for a port.

12.2(25)SE

3750 and 3560

IEEE 802.1x accounting and MIBs (IEEE 8021-PAE-MIB and CISCO-PAE-MIB)

12.2(20)SE

3750, 3560, 2970

Dynamic ARP inspection (IP services image [formerly known as the EMI] only)

12.2(20)SE

3750, 3560

Flex Links

12.2(20)SE

3750, 3560, 2970

Software upgrade (device manager or Network Assistant only)

12.2(20)SE

3750, 3560, 2970

IP source guard (IP services image [formerly known as the EMI] only)

12.2(20)SE

3750, 3560

Private VLAN (IP services image [formerly known as the EMI] only)

12.2(20)SE

3750, 3560

SFP module diagnostic management interface

12.2(20)SE

3750, 3560, 2970

Switch stack offline configuration

12.2(20)SE

3750

Stack-ring activity statistics

12.2(20)SE

3750

Smartports macros

12.2(18)SE

3750, 3560, 2970

1 QoS = quality of service

2 SVIs = switched virtual interfaces


Limitations and Restrictions

You should review this section before you begin working with the switch. These are known limitations that will not be fixed, and there is not always a workaround. Some features might not work as documented, and some features could be affected by recent changes to the switch hardware or software.

This section contains these limitations:

"Cisco IOS Limitations" section

"Device Manager Limitations" section

Cisco IOS Limitations

Unless otherwise noted, these limitations apply to the Catalyst 3750, 3560, and 2970 switches:

"Configuration" section

"Ethernet" section

"Fallback Bridging" section

"HSRP" section

"IP" section

"IP Telephony" section

"MAC Addressing" section

"Management" section

"Multicasting" section

"QoS" section

"Routing" section

"SPAN and RSPAN" section

"Stacking (Catalyst 3750 switch stack only)" section

"Trunking" section

"VLAN" section

Configuration

These are the configuration limitations:

A static IP address might be removed when the previously acquired DHCP IP address lease expires.

This problem occurs under these conditions:

When the switch is booted without a configuration (no config.text file in flash memory).

When the switch is connected to a DHCP server that is configured to give an address to it (the dynamic IP address is assigned to VLAN 1).

When an IP address is configured on VLAN 1 before the dynamic address lease assigned to VLAN 1 expires.

The workaround is to reconfigure the static IP address. (CSCea71176 and CSCdz11708)

(Catalyst 3750 or 3560 switches) When the show interface privileged EXEC is entered on a port that is running IEEE 802.1Q, inconsistent statistics from ports running IEEE 802.1Q might be reported. The workaround is to upgrade to Cisco IOS Release 12.1(20)EA1. (CSCec35100)

(Catalyst 3750 or 3560 switches) When you change a port from a nonrouted port to a routed port or the reverse, the applied auto-QoS setting is not changed or updated when you verify it by using the show running interface or show mls qos interface user EXEC commands. These are the workarounds:

1. Disable auto-QoS on the interface.

2. Change the routed port to a nonrouted port or the reverse.

3. Re-enable auto-QoS on the interface. (CSCec44169)

The DHCP snooping binding database is not written to flash memory or a remote file in any of these situations:

(Catalyst 3750 switch) When the Network Time Protocol (NTP) is configured, but the NTP clock is not synchronized. You can check the clock status by entering the show NTP status privileged EXEC command and verifying that the network connection to the NTP server and the peer work correctly.

(Catalyst 3750, 3560, or 2970 switches) The DHCP snooping database file is manually removed from the file system. After enabling the DHCP snooping database by configuring a database URL, a database file is created. If the file is manually removed from the file system, the DHCP snooping database does not create another database file. You need to disable the DHCP snooping database and enable it again to create the database file.

(Catalyst 3750, 3560, or 2970 switches) The URL for the configured DHCP snooping database was replaced because the original URL was not accessible. The new URL might not take effect after the timeout of the old URL.

No workaround is necessary; these are the designed behaviors. (CSCed50819)

(Catalyst 3750 or 3560 switches) When dynamic ARP inspection is enabled on a switch or switch stack, ARP and RARP packets greater than 2016 bytes are dropped by the switch or switch stack. This is a hardware limitation.

However, when dynamic ARP inspection is not enabled and a jumbo MTU is configured, ARP and RARP packets are correctly bridged in hardware. (CSCed79734)

When connected to some third-party devices that send early preambles, a switch port operating at 100 Mbps full duplex or 100 Mbps half duplex might bounce the line protocol up and down. The problem is observed only when the switch is receiving frames.

The workaround is to configure the port for 10 Mbps and half duplex or to connect a hub or a nonaffected device to the switch. (CSCed39091)

(Catalyst 3750 switches) Dynamic ARP inspection log entries might be lost after a switch failure. Any log entries that are still in the log buffer (have not been output as a system message) on a switch that fails are lost.

When you enter the show ip arp inspection log privileged EXEC command, the log entries from all switches in the stack are moved to the switch on which you entered the command.

There is no workaround. (CSCed95822)

When port security is enabled on an interface in restricted mode and the switchport block unicast interface command has been entered on that interface, MAC addresses are incorrectly forwarded when they should be blocked

The workaround is to enter the no switchport block unicast interface configuration command on that specific interface. (CSCee93822)

A traceback error occurs if a crypto key is generated after an SSL client session.

There is no workaround. This is a cosmetic error and does not affect the functionality of the switch. (CSCef59331)

Ethernet

These are the Ethernet limitations:

Subnetwork Access Protocol (SNAP) encapsulated IP packets are dropped without an error message being reported at the interface. The switch does not support SNAP-encapsulated IP packets. There is no workaround. (CSCdz89142)

Link connectivity might be lost between some older models of the Intel Pro1000 NIC and the 10/100/1000 switch port interfaces. The loss of connectivity occurs between the NIC and these switch ports:

Ports 3, 4, 7, 8, 11, 12, 15, 16, 19, 20, 23, 24 of the Catalyst 3750G-24T and 3750G-24TS switches

Ports 3, 4, 7, 8, 11, 12, 15, 16, 19, 20 of the Catalyst 2970G-24T and 2970G-24TS switches

These are the workarounds:

Contact the NIC vendor, and obtain the latest driver for the card.

Configure the interface for 1000 Mbps instead of for 10/100 Mbps.

Connect the NIC to an interface that is not listed here. (CSCea77032)

For more information, enter CSCea77032 in the Bug Toolkit at this URL:

http://www.cisco.com/cgi-bin/Support/Bugtool/home.pl

Fallback Bridging

These are the fallback bridging limitations:

(Catalyst 3750 or 3560 switches) If a bridge group contains a VLAN to which a static MAC address is configured, all non-IP traffic in the bridge group with this MAC address destination is sent to all ports in the bridge group. The workaround is to remove the VLAN from the bridge group or to remove the static MAC address from the VLAN. (CSCdw81955)

(Catalyst 3750 or 3560 switches) Known unicast (secured) addresses are flooded within a bridge group if secure addresses are learned or configured on a port and the VLAN on this port is part of a bridge group. Non-IP traffic destined to the secure addresses is flooded within the bridge group. The workaround is to disable fallback bridging or to disable port security on all ports in all VLANs participating in fallback bridging. To remove an interface from a bridge group and to remove the bridge group, use the no bridge-group bridge-group interface configuration command. To disable port security on all ports in all VLANs participating in fallback bridging, use the no switchport port-security interface configuration command. (CSCdz80499)

HSRP

This is the Hot Standby Routing Protocol (HSRP) limitation:

When the active switch fails in a switch cluster that uses HSRP redundancy, the new active switch might not contain a full cluster member list. The workaround is to ensure that the ports on the standby cluster members are not in the spanning-tree blocking state. To verify that these ports are not in the blocking state, see the "Configuring STP" chapter in the software configuration guide. (CSCec76893)

IP

These are the IP limitations:

(Catalyst 3750 or 3560 switches) The switch does not create an adjacent table entry when the ARP timeout value is 15 seconds and the ARP request times out. The workaround is to not set an ARP timeout value lower than 120 seconds. (CSCea21674)

When the rate of received DHCP requests exceeds 2,000 packets per minute for a long time, the response time might be slow when you are using the console. The workaround is to use rate limiting on DHCP traffic to prevent a denial of service attack from occurring. (CSCeb59166)

IP Telephony

These are the IP telephony limitations:

Some access point (AP)-350 devices are incorrectly discovered as IEEE 802.3af Class 1 devices. These APs should be discovered as Cisco pre-standard devices. The show power inline user EXEC command shows the AP-350 as an IEEE Class 1 device. The workaround is to power the AP by using an AC wall adaptor. (CSCin69533)

When a Cisco IP Phone is connected to the switch, the port VLAN ID (PVID) and the voice VLAN ID (VVID) both learn its MAC address. However, after dynamic MAC addresses are deleted, only the VVID relearns the phone MAC address. MAC addresses are manually or automatically deleted when a topology change occurs or when port security or an IEEE 802.1x feature is enabled or disabled. There is no workaround. (CSCea80105)

After you change the access VLAN on a port that has IEEE 802.1x enabled, the IP Phone address is removed. Because learning is restricted on IEEE 802.1x capable ports, it takes approximately 30 seconds before the address is relearned. No workaround is necessary. (CSCea85312)

(Catalyst 3750 or 3560 PoE-capable switches) The switch uses the IEEE classification to learn the maximum power consumption of a powered device before powering it. The switch grants power only when the maximum wattage configured on the port is less than or equal to the IEEE class maximum. This ensures that the switch power budget is not oversubscribed. There is no such mechanism in Cisco prestandard powered devices.

The workaround for networks with pre-standard powered devices is to leave the maximum wattage set at the default value (15.4 W). You can also configure the maximum wattage for the port for no less than the value the powered device reports as the power consumption through CDP messages. For networks with IEEE Class 0, 3, or 4 devices, do not configure the maximum wattage for the port at less than the default 15.4 W (15,400 milliwatts). (CSCee80668)

Management

CiscoWorks is not supported on the Catalyst 3750-24FS switch at this time.

MAC Addressing

This is the MAC addressing limitation:

(Catalyst 3750 or 3560 switches) When a MAC address is configured for filtering on the internal VLAN of a routed port, incoming packets from the MAC address to the routed port are not dropped. (CSCeb67937)

Multicasting

These are the multicasting limitations:

(Catalyst 3750 or 3560 switches) The switch does not support tunnel interfaces for unicast routed traffic. Only Distance Vector Multicast Routing Protocol (DVMRP) tunnel interfaces are supported for multicast routing.

(Catalyst 3750 or 3560 switches) Nonreverse-path forwarded (RPF) IP multicast traffic to a group that is bridged in a VLAN is leaked onto a trunk port in the VLAN even if the port is not a member of the group in the VLAN, but it is a member of the group in another VLAN. Because unnecessary traffic is sent on the trunk port, it reduces the bandwidth of the port. There is no workaround for this problem because non-RPF traffic is continuous in certain topologies. As long as the trunk port is a member of the group in at least one VLAN, this problem occurs for the non-RPF traffic. (CSCdu25219)

If the number of multicast routes and Internet Group Management Protocol (IGMP) groups are more than the maximum number specified by the show sdm prefer global configuration command, the traffic received on unknown groups is flooded in the received VLAN even though the show ip igmp snooping multicast-table privileged EXEC command output shows otherwise. The workaround is to reduce the number of multicast routes and IGMP snooping groups to less than the maximum supported value. (CSCdy09008)

IGMP filtering is applied to packets that are forwarded through hardware. It is not applied to packets that are forwarded through software. Hence, with multicast routing enabled, the first few packets are sent from a port even when IGMP filtering is set to deny those groups on that port. There is no workaround. (CSCdy82818)

(Catalyst 3750 or 3560 switches) When you use the ip access-group interface configuration command with a router access control list (ACL) to deny access to a group in a VLAN, multicast data to the group that is received in the VLAN is always flooded in the VLAN, regardless of IGMP group membership in the VLAN. This provides reachability to directly connected clients, if any, in the VLAN. The workaround is to not apply a router ACL set to deny access to a VLAN interface. Apply the security through other means; for example, apply VLAN maps to the VLAN instead of using a router ACL for the group. (CSCdz86110)

(Catalyst 3750 switch stack) If the stack master is power cycled immediately after you enter the ip mroute global configuration command, there is a slight chance that this configuration change might be lost after the stack master changes. This occurs because the stack master did not have time to propagate the running configuration to all the stack members before it was powered down. This problem might also affect other configuration commands. There is no workaround. (CSCea71255)

(Catalyst 3750 switches) When you enable IP Protocol-Independent Multicast (PIM) on a tunnel interface, the switch incorrectly displays the Multicast is not supported on tunnel interfaces error message. IP PIM is not supported on tunnel interfaces. There is no workaround. (CSCeb75366)

If an IG MP report packet has two multicast group records, the switch removes or adds interfaces depending on the order of the records in the packet:

If the ALLOW_NEW_SOURCE record is before the BLOCK_OLD_SOURCE record, the switch removes the port from the group.

If the BLOCK_OLD_SOURCE record is before the ALLOW_NEW_SOURCE record, the switch adds the port to the group.

There is no workaround. (CSCec20128)

When IGMP snooping is disabled and you enter the switchport block multicast interface configuration command, IP multicast traffic is not blocked.

The switchport block multicast interface configuration command is only applicable to non-IP multicast traffic.

There is no workaround. (CSCee16865)

Incomplete multicast traffic can be seen under either of these conditions:

You disable IP multicast routing or re-enable it globally on an interface.

A switch mroute table temporarily runs out of resources and recovers later.

The workaround is to enter the clear ip mroute privileged EXEC command on the interface. (CSCef42436)

QoS

These are the quality of service (QoS) limitations:

Some switch queues are disabled if the buffer size or threshold level is set too low with the mls qos queue-set output global configuration command. The ratio of buffer size to threshold level should be greater than 10 to avoid disabling the queue. The workaround is to choose compatible buffer sizes and threshold levels. (CSCea76893)

When auto-QoS is enabled on the switch, priority queuing is not enabled. Instead, the switch uses shaped round robin (SRR) as the queuing mechanism. The auto-QoS feature is designed on each platform based on the feature set and hardware limitations, and the queuing mechanism supported on each platform might be different. There is no workaround. (CSCee22591)

Routing

These are the routing limitations:

(Catalyst 3750 or 3560 switches) The switch does not support tunnel interfaces for unicast routed traffic. Only Distance Vector Multicast Routing Protocol (DVMRP) tunnel interfaces are supported for multicast routing.

(Catalyst 3750 or 3560 switches) A route map that has an ACL with a Differentiated Services Code Point (DSCP) clause cannot be applied to a Layer 3 interface. The switch rejects this configuration and displays a message that the route map is unsupported. There is no workaround. (CSCea52915)

On a Catalyst 3750 switch stack with a large number of switched virtual interfaces (SVIs), routes, or both on a fully populated nine-member switch stack, this message might appear when you reload the switch stack or add a switch to the stack:

%SYS-2-MALLOCFAIL: Memory allocation of 4252 bytes failed from 0x179C80, alignment 0
Pool: I/O Free: 77124  Cause: Memory fragmentation
Alternate Pool: None Free: 0  Cause: No Alternate pool

This error message means there is a temporary memory shortage that normally recovers by itself. You can verify that the switch stack has recovered by entering the show cef line user EXEC command and verifying that the line card states are up and sync. No workaround is required because the problem is self-correcting. (CSCea71611)

(Catalyst 3750 switches) A spanning-tree loop might occur if all of these conditions are true:

Port security is enabled with the violation mode set to protected.

The maximum number of secure addresses is less than the number of switches connected to the port.

There is a physical loop in the network through a switch whose MAC address has not been secured, and its BPDUs cause a secure violation.

The workaround is to change any one of the listed conditions. (CSCed53633)

SPAN and RSPAN

These are the SPAN and Remote SPAN (RSPAN) limitations.

(Catalyst 3750 or 3560 switches) An egress SPAN copy of routed unicast traffic might show an incorrect destination MAC address on both local and remote SPAN sessions. This limitation does not apply to bridged packets. The workaround for local SPAN is to use the replicate option. For a remote SPAN session, there is no workaround.

This is a hardware limitation and only applies to these switches (CSCdy72835):

3560-24PS

3560-48PS

3750-24PS

3750-48PS

3750-24TS

3750-48TS

3750G-12S

3750G-24T

3750G-24TS

3750G-16TD

Egress SPAN routed packets (both unicast and multicast) show the incorrect source MAC address. For remote SPAN packets, the source MAC address should be the MAC address of the egress VLAN, but instead the packet shows the MAC address of the RSPAN VLAN. For local SPAN packets with native encapsulation on the destination port, the packet shows the MAC address of VLAN 1. This problem does not appear with local SPAN when the encapsulation replicate option is used. This limitation does not apply to bridged packets. The workaround is to use the encapsulate replicate keywords in the monitor session global configuration command. Otherwise, there is no workaround.

This is a hardware limitation and only applies to these switches (CSCdy81521):

2970G-24T

2970G-24TS

3560-24PS

3560-48PS

3750-24PS

3750-48PS

3750-24TS

3750-48TS

3750G-12S

3750G-24T

3750G-24TS

3750G-16TD

During periods of very high traffic, when two RSPAN source sessions are configured, the VLAN ID of packets in one RSPAN session might overwrite the VLAN ID of the other RSPAN session. If this occurs, packets intended for one RSPAN VLAN are incorrectly sent to the other RSPAN VLAN. This problem does not affect RSPAN destination sessions. The workaround is to configure only one RSPAN source session.

This is a hardware limitation and only applies to these switches (CSCea72326):

2970G-24T

2970G-24TS

3560-24PS

3560-48PS

3750-24PS

3750-48PS

3750-24TS

3750-48TS

3750G-12S

3750G-24T

3750G-24TS

3750G-16TD

(Catalyst 3750 or 3560 switches) The egress SPAN data rate might degrade when fallback bridging or multicast routing is enabled. The amount of degradation depends on the processor loading. Typically, the switch can egress SPAN at up to 40,000 packets per second (64-byte packets). As long as the total traffic being monitored is below this limit, there is no degradation. However, if the traffic being monitored exceeds the limit, only a portion of the source stream is spanned. When this occurs, the following console message appears: Decreased egress SPAN rate. In all cases, normal traffic is not affected; the degradation limits only how much of the original source stream can be egress spanned. If fallback bridging and multicast routing are disabled, egress SPAN is not degraded. There is no workaround. If possible, disable fallback bridging and multicast routing. If possible, use ingress SPAN to observe the same traffic. (CSCeb01216)

On Catalyst 3750 switches running Cisco IOS Release 12.1(14)EA1 and later and on Catalyst 3560 switches running Cisco IOS release 12.1(19)EA1 or later, some IGMP report and query packets with IP options might not be ingress-spanned. Packets that are susceptible to this problem are IGMP packets containing 4 bytes of IP options (IP header length of 24). An example of such packets would be IGMP reports and queries having the router alert IP option. Ingress-spanning of such packets is not accurate and can vary with the traffic rate. Typically, very few or none of these packets are spanned. There is no workaround. (CSCeb23352)

Cisco Discovery Protocol (CDP), VLAN Trunking Protocol (VTP), and Port Aggregation Protocol (PAgP) packets received from a SPAN source are not sent to the destination interfaces of a local SPAN session. The workaround is to use the monitor session session_number destination {interface interface-id encapsulation replicate} global configuration command for local SPAN. (CSCed24036)

Stacking (Catalyst 3750 switch stack only)

These are the Catalyst 3750 switch stack limitations:

If the stack master is immediately reloaded after adding multiple VLANs, the new stack master might fail. The workaround is to wait a few minutes after adding VLANs before reloading the stack master. (CSCea26207)

If the console speed is changed on a stack, the configuration file is updated, but the baud rate is not. When the switch is reloaded, meaningless characters might appear on the console during bootup before the configuration file is parsed and the console speed is set to the correct value. If manual boot is enabled or the startup configuration is deleted after you change the console speed, you cannot access the console after the switch reboots. There is no workaround. (CSCec36644)

If a switch is forwarding traffic from a Gigabit ingress interface to a 100 Mbps egress interface, the ingress interface might drop more packets due to oversubscription if the egress interface is on a Fast Ethernet switch (such as a Catalyst 3750-24TS or 3750-48TS switch) than if it is on a Gigabit Ethernet switch (such as a Catalyst 3750G-24T or 3750G-24TS switch). There is no workaround. (CSCed00328)

If a stack member is removed from a stack and either the configuration is not saved or another switch is added to the stack at the same time, the configuration of the first member switch might be lost. The workaround is to save the stack configuration before removing or replacing any switch in the stack. (CSCed15939)

When the switchport and no switchport interface configuration commands are entered more than 20,000 times on a port of a Catalyst 3750 switch, all available memory is used, and the switch halts.

There is no workaround. (CSCed54150)

In a private-VLAN domain, only the default private-VLAN IP gateways have sticky ARP enabled. The intermediate Layer 2 switches that have private VLAN enabled disable sticky ARP. When a stack master switch-over occurs on one of the Catalyst 3750 default IP gateways, the message IP-3-STCKYARPOVR appears on the consoles of other default IP gateways. Because sticky ARP is not disabled, the MAC address update caused by the stack master switch-over cannot complete.

The workaround is to complete the MAC address update by entering the clear arp privileged EXEC command. (CSCed62409)

When a Catalyst 3750 switch is being reloaded in a switch stack, packet loss might occur for up to 1 minute while the Cisco Express Forwarding (CEF) table is downloaded to the switch. This only impacts traffic that will be routed through the switch that is being reloaded. There is no workaround. (CSCed70894)

Inconsistent private-VLAN configuration can occur on a switch stack if a new stack master is running the IP base image (formerly known as the SMI) and the old stack master was running the IP services image (formerly known as the EMI).

Private VLAN is enabled or disabled on a switch stack, depending on whether or not the stack master is running the IP services image (formerly known as the EMI) or the IP base image (formerly known as the SMI):

If the stack master is running the IP services image (formerly known as the EMI), all stack members have private VLAN enabled.

If the stack master is running the IP base image (formerly known as the SMI), all stack members have private VLAN disabled.

This occurs after a stack master re-election when the previous stack master was running the IP services image (formerly known as the EMI) and the new stack master is running the IP base image (formerly known as the SMI). The stack members are configured with private VLAN, but any new switch that joins the stack will have private VLAN disabled.

These are the workarounds. Only one of these is necessary:

Reload the stack after an IP services image (formerly known as the EMI) to IP base image (formerly known as the SMI) master switch change (or the reverse).

Before an IP services image (formerly known as the EMI)-to-IP base image (formerly known as the SMI) master switch change, delete the private-VLAN configuration from the existing stack master. (CSCee06802)

Port configuration information is lost when changing from switchport to no switchport modes on Catalyst 3750 switches.

This is the expected behavior of the offline configuration (provisioning) feature. There is no workaround. (CSCee12431)

Trunking

These are the trunking limitations:

The switch treats frames received with mixed encapsulation (IEEE 802.1Q and Inter-Switch Link [ISL]) as frames with FCS errors, increments the error counters, and the port LED blinks amber. This happens when an ISL-unaware device receives an ISL-encapsulated packet and forwards the frame to an IEEE 802.1Q trunk interface. There is no workaround. (CSCdz33708)

IP traffic with IP options set is sometimes leaked on a trunk port. For example, a trunk port is a member of an IP multicast group in VLAN X but is not a member in VLAN Y. If VLAN Y is the output interface for the multicast route entry assigned to the multicast group and an interface in VLAN Y belongs to the same multicast group, the IP-option traffic received on an input VLAN interface other than one in VLAN Y is sent on the trunk port in VLAN Y because the trunk port is forwarding in VLAN Y, even though the port has no group membership in VLAN Y. There is no workaround. (CSCdz42909).

If a Catalyst 3750 switch stack is connected to a designated bridge and the root port of the switch stack is on a different switch than the alternate root port, changing the port priority of the designated ports on the designated bridge has no effect on the root port selection for the Catalyst 3750 switch stack. There is no workaround. (CSCea40988)

For trunk ports or access ports configured with IEEE 802.1Q tagging, inconsistent statistics might appear in the show interfaces counters privileged EXEC command output. Valid IEEE 802.1Q frames of 64 to 66 bytes are correctly forwarded even though the port LED blinks amber, and the frames are not counted on the interface statistics. There is no workaround. (CSCec35100).

VLAN

These are the VLAN limitations:

If the number of VLANs times the number of trunk ports exceeds the recommended limit of 13,000, the switch can fail.

The workaround is to reduce the number of VLANs or trunks. (CSCeb31087)

(Catalyst 3750 or 3560 switches) A CPUHOG message sometimes appears when you configure a private VLAN. Enable port security on one or more of the ports affected by the private VLAN configuration.

There is no workaround. (CSCed71422)

(Catalyst 3750) When you apply a per-VLAN quality of service (QoS), per-port policer policy-map to a VLAN Switched Virtual Interface (SVI), the second-level (child) policy-map in use cannot be re-used by another policy-map.

The workaround is to define another policy-map name for the second-level policy-map with the same configuration to be used for another policy-map. (CSCef47377)

Device Manager Limitations

When you are prompted to accept the security certificate and you click No, you only see a blank screen, and the device manager does not launch.

The workaround is to click Yes when you are prompted to accept the certificate. (CSCef45718)

Important Notes

These sections describe the important notes related to this software release for the Catalyst 3750, 3560, and 2970 switches:

"Switch Stack Notes" section

"Cisco IOS Notes" section

"Device Manager Notes" section

Switch Stack Notes

These notes apply to switch stacks:

Always power off a switch before adding or removing it from a switch stack.

The Catalyst 3560 and 2970 switches do not support switch stacking. However, the show processes privileged EXEC command still lists stack-related processes. This occurs because these switches share common code with other switches that do support stacking.

Catalyst 3750 switches running Cisco IOS Release 12.2(25)SEB are compatible with Cisco EtherSwitch service modules running Cisco IOS Release 12.2(25)EZ. Catalyst 3750 switches and Cisco EtherSwitch service modules can be in the same switch stack. In this switch stack, the Catalyst 3750 switch or the Cisco EtherSwitch service module can be the stack master.

Cisco IOS Notes

These notes apply to Cisco IOS software:

The IEEE 802.1x feature in Cisco IOS Release 12.1(14)EA1 and later is not fully backward-compatible with the same feature in Cisco IOS Release 12.1(11)AX. If you are upgrading a Catalyst 3750 or a 2970 switch running Cisco IOS Release 12.1(11)AX that has IEEE 802.1x configured, you must re-enable IEEE 802.1x after the upgrade by using the dot1x system-auth-control global configuration command. This global command does not exist in Cisco IOS Release 12.1(11)AX. Failure to re-enable IEEE 802.1x weakens security because some hosts can then access the network without authentication.

The behavior of the no logging on global configuration command changed in Cisco IOS Release 12.2(18)SE and later. In Cisco IOS Release 12.1(19)EA and earlier, both of these command pairs disabled logging to the console:

the no logging on and then the no logging console global configuration commands

the logging on and then the no logging console global configuration commands

In Cisco IOS Release 12.2(18)SE and later, you can only use the logging on and then the no logging console global configuration commands to disable logging to the console. (CSCec71490)

Device Manager Notes

These notes apply to the device manager:

You cannot create and manage switch clusters through the device manager. To create and manage switch clusters, use the CLI or Cisco Network Assistant.

The Legend on the device manager incorrectly includes the 1000BASE-BX SFP module.

We recommend this browser setting to speed up the time needed to display the device manager from Microsoft Internet Explorer.

From Microsoft Internet Explorer:

1. Choose Tools > Internet Options.

2. Click Settings in the "Temporary Internet files" area.

3. From the Settings window, choose Automatically.

4. Click OK.

5. Click OK to exit the Internet Options window.

The HTTP server interface must be enabled to display the device manager. By default, the HTTP server is enabled on the switch. Use the show running-config privileged EXEC command to see if the HTTP server is enabled or disabled.

Beginning in privileged EXEC mode, follow these steps to configure the HTTP server interface:

 
Command
Purpose

Step 1 

configure terminal

Enter global configuration mode.

Step 2 

ip http authentication {aaa | enable | local}

Configure the HTTP server interface for the type of authentication that you want to use.

aaa—Enable the authentication, authorization, and accounting feature. You must enter the aaa new-model interface configuration command for the aaa keyword to appear.

enable—Enable password, which is the default method of HTTP server user authentication, is used.

local—Local user database, as defined on the Cisco router or access server, is used.

Step 3 

end

Return to privileged EXEC mode.

Step 4 

show running-config

Verify your entries.

The device manager uses the HTTP protocol (the default is port 80) and the default method of authentication (the enable password) to communicate with the switch through any of its Ethernet ports and to allow switch management from a standard web browser.

If you change the HTTP port, you must include the new port number when you enter the IP address in the browser Location or Address field (for example, http://10.1.126.45:184 where 184 is the new HTTP port number). You should write down the port number through which you are connected. Use care when changing the switch IP information.

If you are not using the default method of authentication (the enable password), you need to configure the HTTP server interface with the method of authentication used on the switch.

Beginning in privileged EXEC mode, follow these steps to configure the HTTP server interface:

 
Command
Purpose

Step 1 

configure terminal

Enter global configuration mode.

Step 2 

ip http authentication {enable | local | tacacs}

Configure the HTTP server interface for the type of authentication that you want to use.

enable—Enable password, which is the default method of HTTP server user authentication, is used.

local—Local user database, as defined on the Cisco router or access server, is used.

tacacs—TACACS server is used.

Step 3 

end

Return to privileged EXEC mode.

Step 4 

show running-config

Verify your entries.

If you use Internet Explorer Version 5.5 and select a URL with a nonstandard port at the end of the address (for example, www.cisco.com:84), you must enter http:// as the URL prefix. Otherwise, you cannot launch the device manager.

Open Caveats

This section describes the open caveats with possible unexpected activity in this software release. Unless otherwise noted, these severity 3 Cisco IOS configuration caveats apply to the Catalyst 3750, 3560, and 2970 switches:

CSCef37624 (Catalyst 3750 switches)

You cannot ping a Layer 3 interface that has a Network Address Translation (NAT) configuration.

There is no workaround.

CSCef94884 (Catalyst 3750 switches)

Disabling OSPFv3 causes a memory leak.

There is no workaround.

CSCeg27382 (Catalyst 3750 switches)

If the per-VLAN QoS per-port policer policy-map is already attached to a VLAN switched virtual interface (SVI), do not modify the second level (port-level) policy-map. If you modify the policy-map by removing the policer while it is still attached, an error message appears, and the policy-map is detached by the switch. The policer cannot be re-applied back to that policy-map.

The workaround is to redefine the second-level (port level) policy map if the policy map has already been detached by the system.

CSCeh15112 (Catalyst 3750)

When IEEE 802.1x is enabled on one or more ports of a member switch and you enter the show dot1x all privileged EXEC command, the command output does not have IEEE 802.1x information about ports on the member switches.

The workaround is to use the show dot1x interface privileged EXEC command to display the information for a specific interface.

CSCeh15601 (Catalyst 3750)

In a switch stack with Catalyst 3750 switches running Cisco IOS Release 12.2(20)SE4 or Cisco IOS Release 12.2(25)SEA, if the main power supply of a member switch or a redundant power system (RPS) connected to the member switch fails, the switch stack does not generate a ciscoEnvMonMIBNotificationPrefix trap.

However, if the internal power supply of the stack master fails or the RPS status changes, the stack master sends the appropriate trap. If a power supply fails on a member switch, the stack master sends a trap that the RPS is not available. You can use the show env all privileged EXEC command to determine if the power supply of the member switch or the RPS has failed.

The workaround is to configure the trap in CLI using the snmp-server enable traps envmon supply privileged EXEC command. Reboot the slave switch by using the reload slot switch number privileged EXEC command.

CSCeh16869

In an multiple spanning-tree (MST) region in which Switch 1 is connected to Switch 2 and
Switch 2 is connected to Switch 3, if Switch 2 has a root port and a designated port in MST
instance 2, the root port flaps. The designated port is not synchronized with the other switches in the MST region, and the convergence of the port from the blocking state to the learning state is slow.

The workaround is to modify the switch priority to a lower value so that the Switch 2 becomes the root switch for the MST instances 0 and 2.

CSCeh19672

If an IEEE 802.1x client configured for both machine and user authentication is connected to a Catalyst 3750, 3560, 3550, or 2970 switch running Cisco IOS Release 12.2(25)SE and RADIUS VLAN assignment is used only for the machine authentication, the user might take 2 to 5 minutes to authenticate.

Use one of these workarounds:

Use the same VLAN for machine and user authentication.

If the same VLAN cannot be used, reduce the quiet period by using the dot1x timeout quiet-period seconds interface configuration command.

Resolved Caveats

These sections describe the caveats have been resolved in this release. Unless otherwise noted, these resolved caveats apply to the Catalyst 3750, 3560, and 2970 switches:

"Resolved IOS Caveats in Cisco IOS Release 12.2(25)SEB4" section

"Resolved IOS Caveats in Cisco IOS Release 12.2(25)SEB3" section

"Resolved IOS Caveats in Cisco IOS Release 12.2(25)SEB2" section

"Resolved IOS Caveats in Cisco IOS Release 12.2(25)SEB1" section

"Resolved IOS Caveats in Cisco IOS Release 12.2(25)SEB" section

Resolved IOS Caveats in Cisco IOS Release 12.2(25)SEB4

These Cisco IOS caveats were resolved:

CSCei61732

Cisco IOS may permit arbitrary code execution after exploitation of a heap-based buffer overflow vulnerability. Cisco has included additional integrity checks in its software, as further described below, that are intended to reduce the likelihood of arbitrary code execution.

Cisco has made free software available that includes the additional integrity checks for affected customers.

This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20051102-timers.shtml.

CSCei76358

Through normal software maintenance processes, Cisco is removing deprecated functionality. These changes have no impact on system operation or feature availability.

Resolved IOS Caveats in Cisco IOS Release 12.2(25)SEB3

This caveat was resolved:

CSCef68324 (Catalyst 3560 and 3750 switches)

Cisco Internetwork Operating System (IOS) software is vulnerable to a Denial of Service (DoS) and potentially an arbitrary code execution attack from a specifically crafted IPv6 packet. The packet must be sent from a local network segment. Only devices that have been explicitly configured to process IPv6 traffic are affected. Upon successful exploitation, the device may reload or be open to further exploitation.

Cisco has made free software available to address this vulnerability for all affected customers.

More details can be found in the security advisory that is posted at http://www.cisco.com/warp/public/707/cisco-sa-20050729-ipv6.shtml.

Resolved IOS Caveats in Cisco IOS Release 12.2(25)SEB2

These Cisco IOS caveats were resolved:

CSCee45312

Remote Authentication Dial In User Service (RADIUS) authentication on a device that is running certain versions of Cisco Internetworking Operating System (IOS) and configured with a fallback method to none can be bypassed.

Systems that are configured for other authentication methods or that are not configured with a fallback method to none are not affected.

Only the systems that are running certain versions of Cisco IOS are affected.

Not all configurations using RADIUS and none are vulnerable to this issue. Some configurations using RADIUS, none and an additional method are not affected.

Cisco has made free software available to address this vulnerability. There are workarounds available to mitigate the effects of the vulnerability.

Refer to the Security Advisory at the following URL for more details

http://www.cisco.com/warp/public/707/cisco-sa-20050629-aaa.shtml

CSCef88326

When you use the cns config retrieve global configuration command, the switch now gets the configuration of a routing device.

CSCeh13489 (Catalyst 3750 and 3560 switches)

When a switch is running Border Gateway Protocol (BGP) and is peering with other Layer 3 devices, the switch no longer causes other peering devices to reset their BGP sessions if the switch sends BGP advertisements with an AS-path length that is 255 or greater.

CSCeh97062 (Catalyst 3750 and 3560 switches)

While starting, a PoE switch running Cisco IOS Release 12.2(25)SEB1 no longer stops and restarts.

CSCsa74002

If a network scanner is connected to a switch and the number of AAA accounting-request and access-request packets received by the switch port exceeds the ingress buffer size, the ingress interface no longer becomes wedged.

Resolved IOS Caveats in Cisco IOS Release 12.2(25)SEB1

These Cisco IOS caveats were resolved:

CSCeh45368 (Catalyst 3750 switches)

If switch stack with more than five switches reloads or RMON is configured on the stack members, the switches now start correctly and no longer remain in the initializing state.

CSCsa78000

When you enter the show cdp neighbor detail privileged EXEC command, your switch no longer restarts if it is one of these switches:

Catalyst 3750, 3560, 3550, and 2970 switches running Cisco IOS Release 12.2(25)SEA or Cisco IOS Release 12.2(25)SEB

Catalyst 3750 Metro switches running Cisco IOS Release 12.2(25)EY

Resolved IOS Caveats in Cisco IOS Release 12.2(25)SEB

These Cisco IOS caveats were resolved:

CSCef28173

After you enable VLAN-based QoS on a physical port, the previous configuration with the mls qos cos override interface configuration command is removed. The setting to override the packet CoS value is still in effect when you disable VLAN-based QoS.

CSCef60659

A document that describes how the Internet Control Message Protocol (ICMP) could be used to perform a number of Denial of Service (DoS) attacks against the Transmission Control Protocol (TCP) has been made publicly available. This document has been published through the Internet Engineering Task Force (IETF) Internet Draft process, and is entitled "CMP Attacks Against TCP" (draft-gont-tcpm-icmp-attacks-03.txt).

These attacks, which only affect sessions terminating or originating on a device itself, can be of three types:

1. Attacks that use ICMP "hard" error messages
2. Attacks that use ICMP "fragmentation needed and Don't Fragment (DF) bit set" messages, also known as Path Maximum Transmission Unit Discovery (PMTUD) attacks
3. Attacks that use ICMP "source quench" messages

Successful attacks may cause connection resets or reduction of throughput in existing connections, depending on the attack type.

Multiple Cisco products are affected by the attacks described in this Internet draft.

Cisco has made free software available to address these vulnerabilities. In some cases there are workarounds available to mitigate the effects of the vulnerability.

This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20050412-icmp.shtml.

The disclosure of these vulnerabilities is being coordinated by the National Infrastructure Security Coordination Centre (NISCC), based in the United Kingdom. NISCC is working with multiple vendors whose products are potentially affected. Its posting can be found at: http://www.niscc.gov.uk/niscc/docs/re-20050412-00303.pdf?lang=en.

CSCef61610

A document that describes how the Internet Control Message Protocol (ICMP) could be used to perform a number of Denial of Service (DoS) attacks against the Transmission Control Protocol (TCP) has been made publicly available. This document has been published through the Internet Engineering Task Force (IETF) Internet Draft process, and is entitled "ICMP Attacks Against TCP" (draft-gont-tcpm-icmp-attacks-03.txt).

These attacks, which only affect sessions terminating or originating on a device itself, can be of three types:

1. Attacks that use ICMP "hard" error messages
2. Attacks that use ICMP "fragmentation needed and Don't Fragment (DF) bit set" messages, also known as Path Maximum Transmission Unit Discovery (PMTUD) attacks
3. Attacks that use ICMP "source quench" messages

Successful attacks may cause connection resets or reduction of throughput in existing connections, depending on the attack type.

Multiple Cisco products are affected by the attacks described in this Internet draft.

Cisco has made free software available to address these vulnerabilities. In some cases there are workarounds available to mitigate the effects of the vulnerability.

This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20050412-icmp.shtml.

The disclosure of these vulnerabilities is being coordinated by the National Infrastructure Security Coordination Centre (NISCC), based in the United Kingdom. NISCC is working with multiple vendors whose products are potentially affected. Its posting can be found at: http://www.niscc.gov.uk/niscc/docs/re-20050412-00303.pdf?lang=en.

CSCef65928

When a class map of an attached policy map has its match condition removed and is then re-applied, free memory is no longer lost.

CSCeg29704 (Catalyst 3750 and 3560 switches)

When QoS is enabled, bursty and TCP-based applications no longer have significant performance degradation due to unexpected packet drops on some of the egress queues.

CSCeg40067

Both sides of a link no longer stay in the loop-inconsistent state under these conditions:

Rapid PVST is being used.

Loopguard is enabled, and there are multiple paths to the root bridge.

The root is either removed from the network or its priority changes.

CSCeg59320 (Catalyst 3750 switches)

When spanning-tree logging is enabled on a stack of four or more switches, several CPUHOG traceback messages no longer appear if the stack master is reloaded.

CSCeg63653 (Catalyst 3750)

If a combination of VACLs and per-port access control lists (PACLs) are configured in a switch stack such that the TCAM is full and the PACL does not fit into the TCAM, if a master-switch change occurs, an assert message no longer appears stating that the old and new port label for the PACL are the same. A traceback message no longer appears after the assert message.

CSCeh38060

A switch stack no longer generates unnecessary topology change notifications (TCNs) under these conditions:

The stack contains three or more switches. Catalyst 3750 switches can be stacked by using the Stackwise connection. Other Catalyst switches can be stacked by using a Gigastack GBIC.

The stack is running either Cisco IOS Release 12.2(25)SEA or Cisco IOS Release 12.1(22)EA3. (This caveat does not affect any other Cisco IOS release.)

The stack is running cross-stack rapid transition (CSRT) and rapid PVST (rapid PVST+).

Documentation Updates in Cisco IOS Release 12.2(25)SEB

These are the updates to the product documentation that occurred in Cisco IOS Release 12.2(25)SEB.

Updates to the Software Configuration Guides

This section contains these updates to the switch software configuration guides:

"Configuring Interface Characteristics for the Catalyst 3750 Switch" section

"Unsupported CLI Commands" section

"Supported MIBs" section

"Port Security Updates" section

"IGMP Updates" section

"QoS Updates" section

Configuring Interface Characteristics for the Catalyst 3750 Switch

This information was added to the "Configuration Guidelines" section of the "Configuring Interface Speed and Duplex Mode" section in the Catalyst 3750 Switch Software Configuration Guide:

100BASE-FX ports operate only at 100 Mbps in either full- or half-duplex mode and do not support autonegotation.

Unsupported CLI Commands

In Cisco IOS Release 12.1(11)AX and later, the transmit-interface type number interface configuration command is not supported.

In Cisco IOS Release 12.2(25)SEA and later, these commands are not supported:

snmp-server ifindex persist global configuration command

ip pim register-rate-limit global configuration command

Supported MIBs

In Appendix A, "Supported MIBs," the "Using FTP to Access the MIB Files" section was revised. This is the correct procedure.

You can obtain each MIB file by using this procedure:


Step 1 Make sure that your FTP client is in passive mode.


Note Some FTP clients do not support passive mode.


Step 2 Use FTP to access the server ftp.cisco.com.

Step 3 Log in with the username anonymous.

Step 4 Enter your e-mail username when prompted for the password.

Step 5 At the ftp> prompt, change directories to /pub/mibs/v1 and /pub/mibs/v2.

Step 6 Use the get MIB_filename command to get a copy of the MIB file.


Port Security Updates

The port security section was changed in the "Configuring Port-Based Traffic Control" chapter to include port security on voice VLANs. These sections are revised:

"Port Security Configuration Guidelines" section

"Enabling and Configuring Port Security" section

Port Security Configuration Guidelines

Follow these guidelines when configuring port security:

Port security can only be configured on static access ports or trunk ports. A secure port cannot be a dynamic access port.

A secure port cannot be a destination port for Switched Port Analyzer (SPAN).

A secure port cannot belong to a Fast EtherChannel or a Gigabit EtherChannel port group.


Note Voice VLAN is only supported on access ports and not on trunk ports, even though the configuration is allowed.


A secure port cannot be a private-VLAN port. (Catalyst 3750 and 3560 only)

When you enable port security on an interface that is also configured with a voice VLAN, you must set the maximum allowed secure addresses on the port to two plus the maximum number of secure addresses allowed on the access VLAN. When the port is connected to a Cisco IP Phone, the IP phone requires up to two MAC addresses. The IP phone address is learned on the voice VLAN and might also be learned on the access VLAN. Connecting a PC to the IP phone requires additional MAC addresses.

When you enter a maximum secure address value for an interface, and the new value is greater than the previous value, the new value overwrites the previously configured value. If the new value is less than the previous value and the number of configured secure addresses on the interface exceeds the new value, the command is rejected.

The switch does not support port security aging of sticky secure MAC addresses.

Table 7 summarizes port security compatibility with other port-based features.

Table 7 Port Security Compatibility with Other Switch Features 

Type of Port or Feature on Port
Compatible with Port Security

DTP1 port2

No

Trunk port

Yes

Dynamic-access port3

No

Routed port (Catalyst 3750 and 3560 only)

No

SPAN source port

Yes

SPAN destination port

No

EtherChannel

No

Tunneling port (Catalyst 3750 and 3560 only)

Yes

Protected port

Yes

IEEE 802.1x port

Yes

Voice VLAN port4

Yes

Private VLAN port (Catalyst 3750 and 3560 only)

Note The switch must be running the IP services image (formerly known as the EMI).

No

IP source guard (Catalyst 3750 and 3560 only)

Yes

Dynamic ARP5 inspection (Catalyst 3750 and 3560 only)

Yes

Flex Links

Yes

1 DTP = Dynamic Trunking Protocol

2 A port configured with the switchport mode dynamic interface configuration command.

3 A VLAN Query Protocol (VQP) port configured with the switchport access vlan dynamic interface configuration command.

4 You must set the maximum allowed secure addresses on the port to two plus the maximum number of secure addresses allowed on the access VLAN.

5 ARP = Address Resolution Protocol


Enabling and Configuring Port Security

Beginning in privileged EXEC mode, follow these steps to restrict input to an interface by limiting and identifying MAC addresses of the stations allowed to access the port:

 
Command
Purpose

Step 1 

configure terminal

Enter global configuration mode.

Step 2 

interface interface-id

Specify the interface to be configured, and enter interface configuration mode.

Step 3 

switchport mode {access | trunk}

Set the interface switchport mode as access or trunk. An interface in the default mode (dynamic auto) cannot be configured as a secure port.

Step 4 

switchport voice vlan vlan-id

Enable voice VLAN on a port.

vlan-id—Specify the VLAN to be used for voice traffic.

Step 5 

switchport port-security

Enable port security on the interface.

Step 6 

switchport port-security [maximum value [vlan {vlan-list | {access | voice}}]]

(Optional) Set the maximum number of secure MAC addresses for the interface. The maximum number of secure MAC addresses that you can configure on a switch or switch stack is set by the maximum number of available MAC addresses allowed in the system.

On the Catalyst 3750 and 3560, the number is set by the active Switch Database Management (SDM) template. See Chapter 8, "Configuring SDM Templates."

This number is the total of available MAC addresses, including those used for other Layer 2 functions and any other secure MAC addresses configured on interfaces.

(Optional) vlan—set a per-VLAN maximum value

Enter one of these options after you enter the vlan keyword:

vlan-list—On a trunk port, you can set a per-VLAN maximum value on a range of VLANs separated by a hyphen or a series of VLANs separated by commas. For nonspecified VLANs, the per-VLAN maximum value is used.

access—On an access port, specify the VLAN as an access VLAN.

voice—On an access port, specify the VLAN as a voice VLAN.

Note The voice keyword is available only if voice VLAN is configured on a port and if that port is not the access VLAN.

Step 7 

switchport port-security violation {protect | restrict | shutdown}

(Optional) Set the violation mode, the action to be taken when a security violation is detected, as one of these:

protect—When the number of port secure MAC addresses reaches the maximum limit allowed on the port, packets with unknown source addresses are dropped until you remove a sufficient number of secure MAC addresses to drop below the maximum value or increase the number of maximum allowable addresses. You are not notified that a security violation has occurred.

Note We do not recommend configuring the protect mode on a trunk port. The protect mode disables learning when any VLAN reaches its maximum limit, even if the port has not reached its maximum limit.

restrict—When the number of secure MAC addresses reaches the limit allowed on the port, packets with unknown source addresses are dropped until you remove a sufficient number of secure MAC addresses or increase the number of maximum allowable addresses. An SNMP trap is sent, a syslog message is logged, and the violation counter increments.

shutdown—The interface is error-disabled when a violation occurs, and the port LED turns off. An SNMP trap is sent, a syslog message is logged, and the violation counter increments.

Note When a secure port is in the error-disabled state, you can bring it out of this state by entering the errdisable recovery cause psecure-violation global configuration command, or you can manually re-enable it by entering the shutdown and no shutdown interface configuration commands.

Step 8 

switchport port-security [mac-address mac-address [vlan {vlan-id | {access | voice}}]

(Optional) Enter a secure MAC address for the interface. You can use this command to enter the maximum number of secure MAC addresses. If you configure fewer secure MAC addresses than the maximum, the remaining MAC addresses are dynamically learned.

Note If you enable sticky learning after you enter this command, the secure addresses that were dynamically learned are converted to sticky secure MAC addresses and are added to the running configuration.

(Optional) vlan—set a per-VLAN maximum value.

Enter one of these options after you enter the vlan keyword:

vlan-id—On a trunk port, you can specify the VLAN ID and the MAC address. If you do not specify a VLAN ID, the native VLAN is used.

access—On an access port, specify the VLAN as an access VLAN.

voice—On an access port, specify the VLAN as a voice VLAN.

Note The voice keyword is available only if voice VLAN is configured on a port and if that port is not the access VLAN.

Step 9 

switchport port-security mac-address sticky

(Optional) Enable sticky learning on the interface.

Step 10 

switchport port-security mac-address sticky [mac-address | vlan {vlan-id | {access | voice}}]

(Optional) Enter a sticky secure MAC address, repeating the command as many times as necessary. If you configure fewer secure MAC addresses than the maximum, the remaining MAC addresses are dynamically learned, are converted to sticky secure MAC addresses, and are added to the running configuration.

Note If you do not enable sticky learning before this command is entered, an error message appears, and you cannot enter a sticky secure MAC address.

(Optional) vlan—set a per-VLAN maximum value.

Enter one of these options after you enter the vlan keyword:

vlan-id—On a trunk port, you can specify the VLAN ID and the MAC address. If you do not specify a VLAN ID, the native VLAN is used.

access—On an access port, specify the VLAN as an access VLAN.

voice—On an access port, specify the VLAN as a voice VLAN.

Note The voice keyword is available only if voice VLAN is configured on a port and if that port is not the access VLAN.

Step 11 

end

Return to privileged EXEC mode.

Step 12 

show port-security

Verify your entries.

Step 13 

copy running-config startup-config

(Optional) Save your entries in the configuration file.

This example shows how to enable sticky port security on a port, to manually configure MAC addresses for data VLAN and voice VLAN, and to set the total maximum number of secure addresses to 20 (10 for data VLAN and 10 for voice VLAN).

Switch(config)# interface FastEthernet1/0/1
Switch(config-if)# switchport access vlan 21
Switch(config-if)# switchport mode access
Switch(config-if)# switchport voice vlan 22
Switch(config-if)# switchport port-security
Switch(config-if)# switchport port-security maximum 20
Switch(config-if)# switchport port-security violation restrict
Switch(config-if)# switchport port-security mac-address sticky
Switch(config-if)# switchport port-security mac-address sticky 0000.0000.0002
Switch(config-if)# switchport port-security mac-address 0000.0000.0003
Switch(config-if)# switchport port-security mac-address sticky 0000.0000.0001 vlan voice
Switch(config-if)# switchport port-security mac-address 0000.0000.0004 vlan voice
Switch(config-if)# switchport port-security maximum 10 vlan access
Switch(config-if)# switchport port-security maximum 10 vlan voice

IGMP Updates

The configurable IGMP leave timer was added to the "Configuring IGMP Snooping" chapter in this release. These sections describe the timer:

"Understanding the IGMP Configurable-Leave Timer" section

"IGMP Leave Timer Guidelines" section

"Configuring the IGMP Leave Timer" section

Understanding the IGMP Configurable-Leave Timer

In Cisco IOS Release 12.2(25)SEA and earlier, the IGMP snooping leave time was fixed at 5 seconds. If membership reports were not received by the switch before the query response time expired, a port was removed from the multicast group membership. However, some applications require a leave latency of less than 5 seconds.

In Cisco IOS Release 12.2(25)SEB and later, you can configure the time that the switch waits after sending a group-specific query to determine if hosts are still interested in a specific multicast group. The IGMP leave response time can be configured from 100 to 5000 milliseconds. The timer can be set either globally or on a per-VLAN basis. The VLAN configuration of the leave time overrides the global configuration.

IGMP Leave Timer Guidelines

Follows these guidelines when configuring the IGMP leave timer:

You can configure the leave time globally or on a per-VLAN basis.

Configuring the leave time on a VLAN overrides the global setting.

The default leave time is 1000 milliseconds.

The IGMP configurable leave time is only supported on hosts running IGMP Version 2.

The actual leave latency in the network is usually the configured leave time. However, the leave time might vary around the configured time, depending on real-time CPU load conditions, network delays and the amount of traffic sent through the interface.

Configuring the IGMP Leave Timer

Beginning in privileged EXEC mode, follow these steps to configure the IGMP leave timer:

 
Command
Purpose

Step 1 

configure terminal

Enter global configuration mode.

Step 2 

ip igmp snooping last-member-query-interval time

Configure the IGMP leave timer globally. The range is from 100 to 5000 milliseconds.

Step 3 

ip igmp snooping vlan vlan-id last-member-query-interval time

(Optional) Configure the IGMP leave timer on the VLAN interface. The range is from 100 to 5000 milliseconds.

Note Configuring the leave time on a VLAN overrides the globally configured timer.

Step 4 

end

Return to privileged EXEC mode.

Step 5 

show ip igmp snooping

(Optional) Display the configured IGMP leave time.

Step 6 

copy running-config startup-config

(Optional) Save your entries in the configuration file.

Use the no ip igmp snooping last-member-query-interval global configuration command to globally reset the IGMP leave timer to the default setting (1000 milliseconds).

Use the no ip igmp snooping vlan vlan-id last-member-query-interval global configuration command to remove the configured IGMP leave-time setting from the specified VLAN.

For more information about commands that support the IGMP configurable leave time, see these sections:

"ip igmp snooping last-member-query interval" section

"show ip igmp snooping" section

QoS Updates

The default QoS egress queue settings for Queue 2 changed in Cisco IOS Release 12.2(25)SEB. These are the new settings for Queue 2:

Table 8 Default Egress Queue Configuration 

Feature
Queue 1
Queue 2
Queue 3
Queue 4

Buffer allocation

25 percent

25 percent

25 percent

25 percent

WTD drop threshold 1

100 percent

200 percent

100 percent

100 percent

WTD drop threshold 2

100 percent

200 percent

100 percent

100 percent

Reserved threshold

50 percent

50 percent

50 percent

50 percent

Maximum threshold

400 percent

400 percent

400 percent

400 percent

SRR shaped weights (absolute) 1

25

0

0

0

SRR shared weights 2

25

25

25

25

1 A shaped weight of zero means that this queue is operating in shared mode.

2 One quarter of the bandwidth is allocated to each queue.


Updates to the Command Reference

These sections describe the commands that were added or updated in the command reference for this release:

"clear port-security" section

"ip igmp snooping last-member-query interval" section

"show ip igmp snooping" section

"switchport port-security" section

"show version" section

clear port-security

Use the clear port-security privileged EXEC command on the switch stack or on a standalone switch to delete from the MAC address table all secure addresses or all secure addresses of a specific type (configured, dynamic, or sticky) on the switch or on an interface.

clear port-security {all | configured | dynamic | sticky} [[address mac-addr | interface interface-id] [vlan {vlan-id | {access | voice}}]]

Syntax Description

all

Delete all secure MAC addresses.

configured

Delete configured secure MAC addresses.

dynamic

Delete secure MAC addresses auto-learned by hardware.

sticky

Delete secure MAC addresses, either auto-learned or configured.

address mac-addr

(Optional) Delete the specified dynamic secure MAC address.

interface interface-id

(Optional) Delete all the dynamic secure MAC addresses on the specified physical port or VLAN.

vlan

(Optional) Delete the specified secure MAC address from the specified VLAN. Enter one of these options after you enter the vlan keyword:

vlan-id—On a trunk port, specify the VLAN ID of the VLAN on which this address should be cleared.

access—On an access port, clear the specified secure MAC address on the access VLAN.

voice—On an access port, clear the specified secure MAC address on the voice VLAN.

Note The voice keyword is available only if voice VLAN is configured on a port and if that port is not the access VLAN.


Defaults

No default is defined.

Command Modes

Privileged EXEC

Command History

Release
Modification

12.2(25)SEA

This command was introduced.

12.2(25)SEB

The access and voice keywords were added.


Examples

This example shows how to clear all secure addresses from the MAC address table:

Switch# clear port-security all

This example shows how to remove a specific configured secure address from the MAC address table:

Switch# clear port-security configured address 0008.0070.0007

This example shows how to remove all the dynamic secure addresses learned on a specific interface:

Switch# clear port-security dynamic interface gigabitethernet1/0/1

This example shows how to remove all the dynamic secure addresses from the address table:

Switch# clear port-security dynamic

You can verify that the information was deleted by entering the show port-security privileged EXEC command.

Related Commands

Command
Description

switchport port-security

Enables port security on an interface.

switchport port-security mac-address mac-address

Configures secure MAC addresses.

switchport port-security maximum value

Configures a maximum number of secure MAC addresses on a secure interface.

show port-security

Displays the port security settings defined for an interface or for the switch.


ip igmp snooping last-member-query interval

Use the ip igmp snooping last-member-query-interval global configuration command to enable the Internet Group Management Protocol (IGMP) configurable-leave timer globally or on a per-VLAN basis. Use the no form of this command to return the IGMP configurable-leave timer to the default setting.

ip igmp snooping vlan vlan-id last-member-query-interval time

no ip igmp snooping vlan vlan-id last-member-query-interval

Syntax Description

vlan-id

(Optional) Specify a VLAN; the range is 1 to 4094 (available only in privileged EXEC mode).

time

Interval time out in seconds. The range is 100 to 5000 milliseconds.


t

Defaults

The default timeout setting is 1000 milliseconds.

Command History

Release
Modification

12.2(25)SEB

This command was introduced.


Usage Guidelines

When IGMP snooping is globally enabled, IGMP snooping is enabled on all the existing VLAN interfaces. When IGMP snooping is globally disabled, IGMP snooping is disabled on all the existing VLAN interfaces.

Configuring the leave timer on a VLAN overrides the global setting.

The IGMP configurable leave time is only supported on devices running IGMP Version 2.

The configuration is saved in NVRAM.

Examples

This example shows how to globally enable the IGMP leave timer for 2000 milliseconds:

Switch# configure terminal
Switch(config)# ip igmp snooping last-member-query-interval 2000
Switch(config)# end

This example shows how to configure the IGMP leave timer for 3000 milliseconds on VLAN 1:

Switch# configure terminal
Switch(config)# ip igmp snooping vlan 1 last-member-query-interval 3000
Switch(config)# end

This example shows how to globally reset the IGMP leave timer to the default setting:

Switch# configure terminal
Switch(config)# no ip igmp snooping last-member-query-interval
Switch(config)# end

This example shows how to remove the configured IGMP leave timer on VLAN 1. The globally configured leave timer is then applied to VLAN 1:

Switch# configure terminal
Switch(config)# no ip igmp snooping vlan 1 last-member-query-interval
Switch(config)# end

To verify your settings, enter the show ip igmp snooping privileged EXEC command.

Related Commands

Command
Description

ip igmp snooping vlan

Enables IGMP snooping on a VLAN interface.

ip igmp snooping vlan immediate-leave

Enables IGMP Immediate-Leave processing.

ip igmp snooping vlan mrouter

Configures a Layer 2 port as a multicast router port.

ip igmp snooping vlan static

Configures a Layer 2 port as a member of a group.

show ip igmp snooping

Displays the IGMP snooping configuration.


show ip igmp snooping


Note Beginning with Cisco IOS Release 12.2(25)SEB, the value of the IGMP configurable-leave timer is displayed in the output of the show ip igmp snooping command.


Use the show ip igmp snooping user EXEC command to display the Internet Group Management Protocol (IGMP) snooping configuration of the switch or the VLAN.

show ip igmp snooping [groups | mrouter | querier] [vlan vlan-id] [ | {begin | exclude | include} expression]

Syntax Description

groups

(Optional) See the show ip igmp snooping groups command.

mrouter

(Optional) See the show ip igmp snooping mrouter command.

querier

(Optional) Display the IP address and incoming port for the IGMP query most recently received by the switch.

vlan vlan-id

(Optional) Specify a VLAN; the range is 1 to 4094 (available only in privileged EXEC mode).

| begin

(Optional) Display begins with the line that matches the expression.

| exclude

(Optional) Display excludes lines that match the expression.

| include

(Optional) Display includes lines that match the specified expression.

expression

Expression in the output to use as a reference point.


Command Modes

User EXEC

The vlan vlan-id keyword is available only in privileged EXEC mode.

Command History

Release
Modification

12.1(11)AX

This command was introduced.

12.1(19)EA1

The querier keyword was added.

12.2(18)SE

The groups keyword was added. The show ip igmp snooping groups command replaced the show ip igmp snooping multicast command.


Usage Guidelines

Use this command to display snooping configuration for the switch or for a specific VLAN.

Although visible in the output display, output lines for topology change notification (TCN) and source-only learning are not valid.

Use the show ip igmp snooping querier command to display the IGMP version and IP address of a detected device that sends IGMP query messages, which is also called a querier. A subnet can have multiple multicast routers but has only one IGMP querier. In a subnet running IGMPv2, one of the multicast routers is elected as the querier. The querier can be a Layer 3 switch.

The show ip igmp snooping querier command output also shows the VLAN and interface on which the querier was detected. If the querier is the switch, the output shows the Port field as Router. If the querier is a router, the output shows the port number on which the querier is learned in the Port field.

Expressions are case sensitive. For example, if you enterexclude output, the lines that contain output do not appear, but the lines that contain Output appear.

Examples

This is an example of output from the show ip igmp snooping vlan 1 command. It shows snooping characteristics for a specific VLAN.

This is an example of output from the show ip igmp snooping command:

Switch> show ip igmp snooping 
Global IGMP Snooping configuration:
-----------------------------------
IGMP snooping              : Enabled
IGMPv3 snooping (minimal)  : Enabled
Report suppression         : Enabled
TCN solicit query          : Disabled
TCN flood query count      : 2
Last member query interval : 100

Vlan 1:
--------
IGMP snooping                       :Enabled
Immediate leave                     :Disabled
Multicast router learning mode      :pim-dvmrp
Source only learning age timer      :10
Last member query interval          :100
CGMP interoperability mode          :IGMP_ONLY

Vlan 2:
--------
IGMP snooping                       :Enabled
Immediate leave                     :Disabled
Multicast router learning mode      :pim-dvmrp
Source only learning age timer      :10
CGMP interoperability mode          :IGMP_ONLY
Last member query interval          : 333
<output truncated>

This is an example of output from the show ip igmp snooping vlan 1 command:

Switch# show ip igmp snooping vlan 1
Global IGMP Snooping configuration:
-----------------------------------
IGMP snooping              : Enabled
IGMPv3 snooping (minimal)  : Enabled
Report suppression         : Enabled
TCN solicit query          : Disabled
TCN flood query count      : 2
Last member query interval : 100

Vlan 1:
--------
IGMP snooping                       :Enabled
Immediate leave                     :Disabled
Multicast router learning mode      :pim-dvmrp
Source only learning age timer      :10
Last member query interval       				 		: 100
CGMP interoperability mode          :IGMP_ONLY

This is an example of output from the show ip igmp snooping mrouter vlan 1 command:


Note In this example, Fa0/3 is a dynamically learned router port, and Fa0/2 is a configured static router port.


Switch# show ip igmp snooping mrouter vlan 1
Vlan    ports
----    -----
   1    Fa0/2(static), Fa0/3(dynamic) 

This is an example of output from the show ip igmp snooping group vlan 1 command:

Switch# show ip igmp snooping group vlan 1
Vlan      Group          Version     Port List
---------------------------------------------------------
1         229.2.3.4      v3          fa0/1 fa0/3
1         224.1.1.1      v2          fa0/8

This is an example of output from the show ip igmp snooping querier command:

Switch> show ip igmp snooping querier
Vlan      IP Address     IGMP Version        Port
---------------------------------------------------
1         172.20.50.11   v3                  fa0/1

2 172.20.40.20 v2 Router

Related Commands

Command
Description

ip igmp snooping

Enables and configures IGMP snooping on the switch or on a VLAN.

show ip igmp snooping

Displays IGMP snooping multicast router ports for the switch or for the specified multicast VLAN.


show version

This note was added to the show version user EXEC command in the switch command reference:


Note Though visible in the show version output, the configuration register information is not supported on the switch.


switchport port-security

Use the switchport port-security interface configuration command without keywords on the switch stack or on a standalone switch to enable port security on the interface. Use the keywords to configure secure MAC addresses, sticky MAC address learning, a maximum number of secure MAC addresses, or the violation mode. Use the no form of this command to disable port security or to set the parameters to their default states.

switchport port-security [mac-address mac-address [vlan {vlan-id | {access | voice}}] | mac-address sticky [mac-address | vlan {vlan-id | {access | voice}}]] [maximum value [vlan {vlan-list | {access | voice}}]]

no switchport port-security [mac-address mac-address [vlan {vlan-id | {access | voice}}] | mac-address sticky [mac-address | vlan {vlan-id | {access | voice}}]] [maximum value [vlan {vlan-list | {access | voice}}]]

switchport port-security [aging] [violation {protect | restrict | shutdown}]

no switchport port-security [aging] [violation {protect | restrict | shutdown}]

Syntax Description

aging

(Optional) See the switchport port-security aging command.

mac-address mac-address

(Optional) Specify a secure MAC address for the interface by entering a 48-bit MAC address. You can add additional secure MAC addresses up to the maximum value configured.

vlan vlan-id

(Optional) On a trunk port only, specify the VLAN ID and the MAC address. If no VLAN ID is specified, the native VLAN is used.

vlan access

(Optional) On an access port only, specify the VLAN as an access VLAN.

vlan voice

(Optional) On an access port only, specify the VLAN as a voice VLAN.

Note The voice keyword is available only if voice VLAN is configured on a port and if that port is not the access VLAN.

mac-address sticky [mac-address]

(Optional) Enable the interface for sticky learning by entering only the mac-address sticky keywords. When sticky learning is enabled, the interface adds all secure MAC addresses that are dynamically learned to the running configuration and converts these addresses to sticky secure MAC addresses.

(Optional) Enter a mac-address to specify a sticky secure MAC address.

maximum value

(Optional) Set the maximum number of secure MAC addresses for the interface.

The maximum number of secure MAC addresses that you can configure on a switch or switch stack is set by the maximum number of available MAC addresses allowed in the system. It is approximately 6000 for the Catalyst 2970 switches. For the Catalyst 3750 and 3560 switches, this number is determined by the active Switch Database Management (SDM) template. See the sdm prefer command.

This number represents the total of available MAC addresses, including those used for other Layer 2 functions and any other secure MAC addresses configured on interfaces.

The default setting is 1.

vlan [vlan-list]

(Optional) For trunk ports, you can set the maximum number of secure MAC addresses on a VLAN. If the vlan keyword is not entered, the default value is used.

vlan—set a per-VLAN maximum value.

vlan vlan-list—set a per-VLAN maximum value on a range of VLANs separated by a hyphen or a series of VLANs separated by commas. For nonspecified VLANs, the per-VLAN maximum value is used.

violation

(Optional) Set the security violation mode or the action to be taken if port security is violated. The default is shutdown.

protect

Set the security violation protect mode. In this mode, when the number of port secure MAC addresses reaches the maximum limit allowed on the port, packets with unknown source addresses are dropped until you remove a sufficient number of secure MAC addresses to drop below the maximum value or increase the number of maximum allowable addresses. You are not notified that a security violation has occurred.

Note We do not recommend configuring the protect mode on a trunk port. The protect mode disables learning when any VLAN reaches its maximum limit, even if the port has not reached its maximum limit.

restrict

Set the security violation restrict mode. In this mode, when the number of secure MAC addresses reaches the limit allowed on the port, packets with unknown source addresses are dropped until you remove a sufficient number of secure MAC addresses or increase the number of maximum allowable addresses. An SNMP trap is sent, a syslog message is logged, and the violation counter increments.

shutdown

Set the security violation shutdown mode. In this mode, the interface is error-disabled when a violation occurs and the port LED turns off. An SNMP trap is sent, a syslog message is logged, and the violation counter increments. When a secure port is in the error-disabled state, you can bring it out of this state by entering the errdisable recovery cause psecure-violation global configuration command, or you can manually re-enable it by entering the shutdown and no shut down interface configuration commands.


Defaults

The default is to disable port security.

When port security is enabled and no keywords are entered, the default maximum number of secure MAC addresses is 1.

The default violation mode is shutdown.

Sticky learning is disabled.

Command Modes

Interface configuration

Command History

Release
Modification

12.2(25)SEB

The access and voice keywords were added.


Usage Guidelines

A secure port has these limitations:

A secure port can be an access port or a trunk port; it cannot be a dynamic access port.

A secure port cannot be a routed port. (Catalyst 3750 and 3560 only)

A secure port cannot be a protected port.

A secure port cannot be a destination port for Switched Port Analyzer (SPAN).

A secure port cannot be a private-VLAN port. (Catalyst 3750 and 3560 only)

A secure port cannot belong to a Fast EtherChannel or Gigabit EtherChannel port group.

When you enable port security on an interface that is also configured with a voice VLAN, you must set the maximum allowed secure addresses on the port to two plus the maximum number of secure addresses allowed on the access VLAN. When the port is connected to a Cisco IP Phone, the Cisco IP Phone requires up to two MAC addresses. The Cisco IP Phone address is learned on the voice VLAN and might also be learned on the access VLAN. Connecting a PC to the Cisco IP Phone requires additional MAC addresses.

Voice VLAN is supported only on access ports and not on trunk ports.

When you enter a maximum secure address value for an interface, if the new value is greater than the previous value, the new value overrides the previously configured value. If the new value is less than the previous value and the number of configured secure addresses on the interface exceeds the new value, the command is rejected.

The switch does not support port security aging of sticky secure MAC addresses.

A security violation occurs when the maximum number of secure MAC addresses are in the address table and a station whose MAC address is not in the address table attempts to access the interface or when a station whose MAC address is configured as a secure MAC address on another secure port attempts to access the interface.

If you enable port security on a voice VLAN port and if there is a PC connected to the IP phone, you should set the maximum allowed secure addresses on the port to more than 1.

When a secure port is in the error-disabled state, you can bring it out of this state by entering the errdisable recovery cause psecure-violation global configuration command, or you can manually re-enable it by entering the shutdown and no shut down interface configuration commands.

Setting a maximum number of addresses to one and configuring the MAC address of an attached device ensures that the device has the full bandwidth of the port.

When you enter a maximum secure address value for an interface, this occurs:

If the new value is greater than the previous value, the new value overrides the previously configured value.

If the new value is less than the previous value and the number of configured secure addresses on the interface exceeds the new value, the command is rejected.

Sticky secure MAC addresses have these characteristics:

When you enable sticky learning on an interface by using the switchport port-security mac-address sticky interface configuration command, the interface converts all the dynamic secure MAC addresses, including those that were dynamically learned before sticky learning was enabled, to sticky secure MAC addresses and adds all sticky secure MAC addresses to the running configuration.

If you disable sticky learning by using the no switchport port-security mac-address sticky interface configuration command, the sticky secure MAC addresses are converted to dynamic secure addresses and are removed from the running configuration. If you remove the sticky MAC addresses from the running configuration, the sticky secure MAC addresses are removed from the running configuration and the address table.

When you configure sticky secure MAC addresses by using the switchport port-security mac-address sticky mac-address interface configuration command, these addresses are added to the address table and the running configuration. If port security is disabled, the sticky secure MAC addresses remain in the running configuration.

If you save the sticky secure MAC addresses in the configuration file, when the switch restarts or the interface shuts down, the interface does not need to relearn these addresses. If you do not save the sticky secure addresses, they are lost. If sticky learning is disabled, the sticky secure MAC addresses are converted to dynamic secure addresses and are removed from the running configuration.

If you disable sticky learning and enter the switchport port-security mac-address sticky mac-address interface configuration command, an error message appears, and the sticky secure MAC address is not added to the running configuration.

Examples

This example shows how to enable port security on a port and to set the maximum number of secure addresses to 5. The violation mode is the default, and no secure MAC addresses are configured.

Switch(config)# interface gigabitethernet 2/0/2
Switch(config-if)# switchport mode access
Switch(config-if)# switchport port-security
Switch(config-if)# switchport port-security maximum 5

This example shows how to configure a secure MAC address and a VLAN ID on a port.

Switch(config)# interface gigabitethernet 2/0/2
Switch(config-if)# switchport mode trunk
Switch(config-if)# switchport port-security
Switch(config-if)# switchport port-security mac-address 1000.2000.3000 vlan 3

This example shows how to enable sticky learning and to enter two sticky secure MAC addresses on a port:

Switch(config)# interface gigabitethernet 2/0/2
Switch(config-if)# switchport port-security mac-address sticky 
Switch(config-if)# switchport port-security mac-address sticky 0000.0000.4141
Switch(config-if)# switchport port-security mac-address sticky 0000.0000.000f

You can verify your settings by using the show port-security privileged EXEC command.

Related Commands

Command
Description

clear port-security

Deletes from the MAC address table a specific type of secure address or all the secure addresses on the switch or an interface.

show port-security address

Displays all the secure addresses configured on the switch.

show port-security
interface
interface-id

Displays port security configuration for the switch or for the specified interface.


Documentation Updates in Cisco IOS Release 12.2(25)SEA

These are the updates to the product documentation that occurred in Cisco IOS Release 12.2(25)SEA:

"Correction to the Software Configuration Guides" section

"Updates for the Software Configuration Guides" section

"Updates for the Command Reference" section

Correction to the Software Configuration Guides

This is a correction to the software configuration guides for this release:

The "Configuring a System Name and Prompt" section and the "Configuring a System Prompt" section of the "Administering the Switch" chapter incorrectly state that you can manually configure the prompt global configuration command. The switches do not support this command. You should ignore this information in printed and online copies of the software configuration guides.

Updates for the Software Configuration Guides

These are updates to the software configuration guides for this release:

In the "DHCP Snooping Binding Database" section in the "Configuring DHCP Features and IP Source Guard" chapter, the information in the third and fifth paragraphs is incorrect. This is the correct information:

To keep the bindings when the switch reloads, you must use the DHCP snooping database agent. If the agent is disabled, dynamic ARP or IP source guard is enabled, and the DHCP snooping binding database has dynamic bindings, the switch loses its connectivity. If the agent is disabled and only DHCP snooping is enabled, the switch does not lose its connectivity, but DHCP snooping might not prevent DCHP spoofing attacks.

When a switch learns of new bindings or when it loses bindings, the switch immediately updates the entries in the database. The switch also updates the entries in the binding file. The frequency at which the file is updated is based on a configurable delay, and the updates are batched. If the file is not updated in a specified time (set by the write-delay and abort-timeout values), the update stops.

In the "Enabling the DHCP Snooping Binding Database Agent" section in the "Configuring DHCP Features and IP Source Guard" chapter, the information is added to Step 6:

Use the ip dhcp snooping binding privileged EXEC command when you are testing or debugging the switch.

In the "Enabling the DHCP Snooping Binding Database Agent" section in the "Configuring DHCP Features and IP Source Guard" chapter, the information about the no ip dhcp snooping database global configuration command is incorrect. This is the correct information:

To stop using the database agent and bindings file, use the no ip dhcp snooping database global configuration command.

Updates for the Command Reference

The description and usage guidelines for the ip dhcp snooping database global configuration command are incorrect. This is the correct information:

Use the ip dhcp snooping database global configuration command to configure the DHCP snooping binding database agent. Use the no form of this command to disable the agent, to reset the timeout value, or to reset the write-delay value.

If NTP is configured, the switch writes binding changes to the binding file only when the switch system clock is synchronized with NTP.

Use the no ip dhcp snooping database command to disable the agent.

Related Documentation

These documents provide complete information about the Catalyst 3750, 3560, and 2970 switches and are available at Cisco.com:

http://www.cisco.com/univercd/cc/td/doc/product/lan/cat3750/index.htm

http://www.cisco.com/univercd/cc/td/doc/product/lan/cat3560/index.htm

http://www.cisco.com/univercd/cc/td/doc/product/lan/cat2970/index.htm

You can order printed copies of documents with a DOC-xxxxxx= number from the Cisco.com sites and from the telephone numbers listed in the "Obtaining Documentation" section.

These documents provide complete information about the Catalyst 3750 switches:

Catalyst 3750 Switch Software Configuration Guide (order number DOC-7816180=)

Catalyst 3750 Switch Command Reference (order number DOC-7816181=)

Catalyst 3750 Switch System Message Guide (order number DOC-7816184=)

Catalyst 3750 Switch System Message Guide (order number DOC-7816184=)

Device manager online help (available on the switch)

Catalyst 3750 Switch Hardware Installation Guide (not orderable but available on Cisco.com)

Catalyst 3750 Switch Getting Started Guide (order number DOC-7816663=)

Regulatory Compliance and Safety Information for the Catalyst 3750 Switch (order number DOC-7816664)

These documents provide complete information about the Catalyst 3560 switches:

Catalyst 3560 Switch Software Configuration Guide (order number DOC-7816404=)

Catalyst 3560 Switch Command Reference (order number DOC-7816405=)

Catalyst 3560 Switch System Message Guide (order number DOC-7816406=)

Device manager online help (available on the switch)

Catalyst 3560 Switch Hardware Installation Guide (not orderable but available on Cisco.com)

Catalyst 3560 Switch Getting Started Guide (order number DOC-7816660=)

Regulatory Compliance and Safety Information for the Catalyst 3560 Switch (order number DOC-7816665)

These documents provide complete information about the Catalyst 2970 switches:

Catalyst 2970 Switch Software Configuration Guide (order number DOC-7816182=)

Catalyst 2970 Switch Command Reference (order number DOC-7816183=)

Catalyst 2970 Switch System Message Guide (order number DOC-7816185=)

Device manager online help (available on the switch)

Catalyst 2970 Switch Hardware Installation Guide (not orderable but available on Cisco.com)

Catalyst 2970 Switch Getting Started Guide (order number DOC-7816685=)

Regulatory Compliance and Safety Information for the Catalyst 2970 Switch (order number DOC-7816686=)

For other information about related products, see these documents:

Getting Started with Cisco Network Assistant (not orderable but available on Cisco.com)

Release Notes for Cisco Network Assistant (not orderable but available on Cisco.com)

Cisco Small Form-Factor Pluggable Modules Installation Notes (order number DOC-7815160=)

Cisco CWDM GBIC and CWDM SFP Installation Note (not orderable but available on Cisco.com)

Cisco RPS 300 Redundant Power System Hardware Installation Guide (order number DOC-7810372=)

Cisco RPS 675 Redundant Power System Hardware Installation Guide (order number DOC-7815201=)

Obtaining Documentation

Cisco documentation and additional literature are available on Cisco.com. Cisco also provides several ways to obtain technical assistance and other technical resources. These sections explain how to obtain technical information from Cisco Systems.

Cisco.com

You can access the most current Cisco documentation at this URL:

http://www.cisco.com/techsupport

You can access the Cisco website at this URL:

http://www.cisco.com

You can access international Cisco websites at this URL:

http://www.cisco.com/public/countries_languages.shtml

Product Documentation DVD

Cisco documentation and additional literature are available in the Product Documentation DVD package, which may have shipped with your product. The Product Documentation DVD is updated regularly and may be more current than printed documentation.

The Product Documentation DVD is a comprehensive library of technical product documentation on portable media. The DVD enables you to access multiple versions of hardware and software installation, configuration, and command guides for Cisco products and to view technical documentation in HTML. With the DVD, you have access to the same documentation that is found on the Cisco website without being connected to the Internet. Certain products also have .pdf versions of the documentation available.

The Product Documentation DVD is available as a single unit or as a subscription. Registered Cisco.com users (Cisco direct customers) can order a Product Documentation DVD (product number DOC-DOCDVD=) from the Ordering tool or Cisco Marketplace.

Cisco Ordering tool:

http://www.cisco.com/en/US/partner/ordering/

Cisco Marketplace:

http://www.cisco.com/go/marketplace/

Ordering Documentation

Beginning June 30, 2005, registered Cisco.com users may order Cisco documentation at the Product Documentation Store in the Cisco Marketplace at this URL:

http://www.cisco.com/go/marketplace/

Cisco will continue to support documentation orders using the Ordering tool:

Registered Cisco.com users (Cisco direct customers) can order documentation from the Ordering tool:

http://www.cisco.com/en/US/partner/ordering/

Instructions for ordering documentation using the Ordering tool are at this URL:

http://www.cisco.com/univercd/cc/td/doc/es_inpck/pdi.htm

Nonregistered Cisco.com users can order documentation through a local account representative by calling Cisco Systems Corporate Headquarters (California, USA) at 408 526-7208 or, elsewhere in North America, by calling 1 800 553-NETS (6387).

Documentation Feedback

You can rate and provide feedback about Cisco technical documents by completing the online feedback form that appears with the technical documents on Cisco.com.

You can send comments about Cisco documentation to bug-doc@cisco.com.

You can submit comments by using the response card (if present) behind the front cover of your document or by writing to the following address:

Cisco Systems
Attn: Customer Document Ordering
170 West Tasman Drive
San Jose, CA 95134-9883

We appreciate your comments.

Cisco Product Security Overview

Cisco provides a free online Security Vulnerability Policy portal at this URL:

http://www.cisco.com/en/US/products/products_security_vulnerability_policy.html

From this site, you can perform these tasks:

Report security vulnerabilities in Cisco products.

Obtain assistance with security incidents that involve Cisco products.

Register to receive security information from Cisco.

A current list of security advisories and notices for Cisco products is available at this URL:

http://www.cisco.com/go/psirt

If you prefer to see advisories and notices as they are updated in real time, you can access a Product Security Incident Response Team Really Simple Syndication (PSIRT RSS) feed from this URL:

http://www.cisco.com/en/US/products/products_psirt_rss_feed.html

Reporting Security Problems in Cisco Products

Cisco is committed to delivering secure products. We test our products internally before we release them, and we strive to correct all vulnerabilities quickly. If you think that you might have identified a vulnerability in a Cisco product, contact PSIRT:

Emergencies — security-alert@cisco.com

An emergency is either a condition in which a system is under active attack or a condition for which a severe and urgent security vulnerability should be reported. All other conditions are considered nonemergencies.

Nonemergencies — psirt@cisco.com

In an emergency, you can also reach PSIRT by telephone:

1 877 228-7302

1 408 525-6532


Tip We encourage you to use Pretty Good Privacy (PGP) or a compatible product to encrypt any sensitive information that you send to Cisco. PSIRT can work from encrypted information that is compatible with PGP versions 2.x through 8.x.

Never use a revoked or an expired encryption key. The correct public key to use in your correspondence with PSIRT is the one linked in the Contact Summary section of the Security Vulnerability Policy page at this URL:

http://www.cisco.com/en/US/products/products_security_vulnerability_policy.htm

The link on this page has the current PGP key ID in use.


Obtaining Technical Assistance

Cisco Technical Support provides 24-hour-a-day award-winning technical assistance. The Cisco Technical Support & Documentation website on Cisco.com features extensive online support resources. In addition, if you have a valid Cisco service contract, Cisco Technical Assistance Center (TAC) engineers provide telephone support. If you do not have a valid Cisco service contract, contact your reseller.

Cisco Technical Support & Documentation Website

The Cisco Technical Support & Documentation website provides online documents and tools for troubleshooting and resolving technical issues with Cisco products and technologies. The website is available 24 hours a day, at this URL:

http://www.cisco.com/techsupport

Access to all tools on the Cisco Technical Support & Documentation website requires a Cisco.com user ID and password. If you have a valid service contract but do not have a user ID or password, you can register at this URL:

http://tools.cisco.com/RPF/register/register.do


Note Use the Cisco Product Identification (CPI) tool to locate your product serial number before submitting a web or phone request for service. You can access the CPI tool from the Cisco Technical Support & Documentation website by clicking the Tools & Resources link under Documentation & Tools. Choose Cisco Product Identification Tool from the Alphabetical Index drop-down list, or click the Cisco Product Identification Tool link under Alerts & RMAs. The CPI tool offers three search options: by product ID or model name; by tree view; or for certain products, by copying and pasting show command output. Search results show an illustration of your product with the serial number label location highlighted. Locate the serial number label on your product and record the information before placing a service call.


Submitting a Service Request

Using the online TAC Service Request Tool is the fastest way to open S3 and S4 service requests. (S3 and S4 service requests are those in which your network is minimally impaired or for which you require product information.) After you describe your situation, the TAC Service Request Tool provides recommended solutions. If your issue is not resolved using the recommended resources, your service request is assigned to a Cisco engineer. The TAC Service Request Tool is located at this URL:

http://www.cisco.com/techsupport/servicerequest

For S1 or S2 service requests or if you do not have Internet access, contact the Cisco TAC by telephone. (S1 or S2 service requests are those in which your production network is down or severely degraded.) Cisco engineers are assigned immediately to S1 and S2 service requests to help keep your business operations running smoothly.

To open a service request by telephone, use one of the following numbers:

Asia-Pacific: +61 2 8446 7411 (Australia: 1 800 805 227)
EMEA: +32 2 704 55 55
USA: 1 800 553-2447

For a complete list of Cisco TAC contacts, go to this URL:

http://www.cisco.com/techsupport/contacts

Definitions of Service Request Severity

To ensure that all service requests are reported in a standard format, Cisco has established severity definitions.

Severity 1 (S1)—Your network is "down," or there is a critical impact to your business operations. You and Cisco will commit all necessary resources around the clock to resolve the situation.

Severity 2 (S2)—Operation of an existing network is severely degraded, or significant aspects of your business operation are negatively affected by inadequate performance of Cisco products. You and Cisco will commit full-time resources during normal business hours to resolve the situation.

Severity 3 (S3)—Operational performance of your network is impaired, but most business operations remain functional. You and Cisco will commit resources during normal business hours to restore service to satisfactory levels.

Severity 4 (S4)—You require information or assistance with Cisco product capabilities, installation, or configuration. There is little or no effect on your business operations.

Obtaining Additional Publications and Information

Information about Cisco products, technologies, and network solutions is available from various online and printed sources.

Cisco Marketplace provides a variety of Cisco books, reference guides, documentation, and logo merchandise. Visit Cisco Marketplace, the company store, at this URL:

http://www.cisco.com/go/marketplace/

Cisco Press publishes a wide range of general networking, training and certification titles. Both new and experienced users will benefit from these publications. For current Cisco Press titles and other information, go to Cisco Press at this URL:

http://www.ciscopress.com

Packet magazine is the Cisco Systems technical user magazine for maximizing Internet and networking investments. Each quarter, Packet delivers coverage of the latest industry trends, technology breakthroughs, and Cisco products and solutions, as well as network deployment and troubleshooting tips, configuration examples, customer case studies, certification and training information, and links to scores of in-depth online resources. You can access Packet magazine at this URL:

http://www.cisco.com/packet

iQ Magazine is the quarterly publication from Cisco Systems designed to help growing companies learn how they can use technology to increase revenue, streamline their business, and expand services. The publication identifies the challenges facing these companies and the technologies to help solve them, using real-world case studies and business strategies to help readers make sound technology investment decisions. You can access iQ Magazine at this URL:

http://www.cisco.com/go/iqmagazine

or view the digital edition at this URL:

http://ciscoiq.texterity.com/ciscoiq/sample/

Internet Protocol Journal is a quarterly journal published by Cisco Systems for engineering professionals involved in designing, developing, and operating public and private internets and intranets. You can access the Internet Protocol Journal at this URL:

http://www.cisco.com/ipj

Networking products offered by Cisco Systems, as well as customer support services, can be obtained at this URL:

http://www.cisco.com/en/US/products/index.html

Networking Professionals Connection is an interactive website for networking professionals to share questions, suggestions, and information about networking products and technologies with Cisco experts and other networking professionals. Join a discussion at this URL:

http://www.cisco.com/discuss/networking

World-class networking training is available from Cisco. You can view current offerings at this URL:

http://www.cisco.com/en/US/learning/index.html