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Cisco Catalyst 3550 Series Switches

Release Notes for the Catalyst 3550-24-DC Multilayer Switch, Cisco IOS Release 12.2(50)SE and Later

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Release Notes for the Catalyst 3550-24-DC Multilayer Switch, Cisco IOS Release 12.2(50)SE and Later

Table Of Contents

Release Notes for the Catalyst 3550-24-DC Multilayer Switch, Cisco IOS Release 12.2(50)SE and Later

Contents

System Requirements

Hardware Supported

Device Manager System Requirements

Hardware Requirements

Software Requirements

Cluster Compatibility

CNA Compatibility

Upgrading the Switch Software

Finding the Software Version and Feature Set Running on the Switch

Deciding Which Files to Download from Cisco.com

Archiving Software Images

Upgrading a Switch by Using Device Manager or Network Assistant

Upgrading a Switch by Using the CLI

Upgrading with a Nondefault System MTU Setting

Recovering from a Software Failure

Installation Notes

New Features

New Hardware Features

New Software Features

Limitations and Restrictions

Cisco IOS Limitations and Restrictions

IEEE 802.1x

ACLs

Connected Devices

Configuration

DHCP

EtherChannel

HSRP

IGMP

IP

MAC Addressing

MIBs

Multicasting

Port Security

QoS

Routing

SNMP

SPAN and RSPAN

Spanning Tree

VLAN

Important Notes

Cisco IOS Notes

Device Manager Notes

Open Caveats

Resolved Caveats

Cisco IOS Caveats Resolved in Cisco IOS Release 12.2(50)SE5

Cisco IOS Caveats Resolved in Cisco IOS Release 12.2(50)SE4

Cisco IOS Caveats Resolved in Cisco IOS Release 12.2(50)SE3

Cisco IOS Caveats Resolved in Cisco IOS Release 12.2(50)SE1

Cisco IOS Caveats Resolved in Cisco IOS Release 12.2(50)SE

Documentation Updates

Updates for the Software Configuration Guide

Updates for the Command Reference

Updates for the Regulatory Compliance and Safety Information for the Catalyst 3550 Multilayer Switch

Update to the Hardware Installation Guide

Update to the Getting Start Guide

Update to the System Message Guide

New System Messages

Changed System Messages

Deleted System Messages

Related Documentation

Obtaining Documentation, Obtaining Support, and Security Guidelines


Release Notes for the Catalyst 3550-24-DC Multilayer Switch, Cisco IOS Release 12.2(50)SE and Later


Revised October 5, 2010

Cisco IOS Release 12.2(50)SE and later runs only on the Catalyst 3550-24-DC multilayer switch.

These release notes include important information about Cisco IOS Release 12.2(50)SE and later and any limitations, restrictions, and caveats that apply to them. Verify that these are the correct release notes for your switch:

If you are installing a new switch, refer to 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 Running on the Switch" section.

If you are upgrading to a new release, refer to the software upgrade filename for the Cisco IOS version. See the "Deciding Which Files to Download from Cisco.com" section.

For the complete list of Catalyst 3550 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://tools.cisco.com/support/downloads/go/MDFTree.x?butype=switches

This Cisco IOS 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 Cisco IOS releases become available, they will be posted to Cisco.com in the Cisco IOS software area.

Contents

This information is in the release notes:

"System Requirements" section

"Upgrading the Switch Software" section

"Installation Notes" section

"New Features" section

"Limitations and Restrictions" section

"Important Notes" section

"Open Caveats" section

"Resolved Caveats" section

"Documentation Updates" section

"Related Documentation" section

"Obtaining Documentation, Obtaining Support, and Security Guidelines" section

System Requirements

The system requirements for this release are described in these sections:

"Hardware Supported" section

"Device Manager System Requirements" section

"Cluster Compatibility" section

"CNA Compatibility" section

Hardware Supported

Table 1 lists the hardware supported by this release.

Table 1 Supported Hardware 

Switch
Description

Catalyst 3550-24-DC

24 autosensing 10/100 Ethernet ports, 2 GBIC-based Gigabit Ethernet slots, and an on-board DC power converter

GBIC modules

1000BASE-SX GBIC

1000BASE-LX/LH GBIC

1000BASE-ZX GBIC

1000BASE-T GBIC

GigaStack GBIC

CWDM1 fiber-optic GBIC

DWDM2 fiber-optic GBIC

1 CWDM = coarse wavelength-division multiplexing

2 DWDM = dense wavelength-division multiplexing


Device Manager System Requirements

These sections describe 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

233 MHz minimum1

512 MB2

256

1024 x 768

Small

1 We recommend 1 GHz.

2 We recommend 1 GB DRAM.


Software Requirements

These are the supported operating systems and browsers for the device manager:

Windows 2000, XP, Vista, and Windows Server 2003.

Internet Explorer 5.5, 6.0, 7.0, Firefox 1.5, 2.0 or later.

The device manager verifies the browser version when starting a session, and it does not require a plug-in.

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.

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 the Getting Started with Cisco Network Assistant and the Release Notes for Cisco Network Assistant, the software configuration guide, and the command reference.

CNA Compatibility

Cisco IOS 12.2(46)SE and later is only compatible with Cisco Network Assistant (CNA) 5.0 and later. You can download Cisco Network Assistant from this URL:

http://www.cisco.com/pcgi-bin/tablebuild.pl/NetworkAssistant

For more information about Cisco Network Assistant, see the Release Notes for Cisco Network Assistant on Cisco.com.

Upgrading the Switch Software

Before downloading software from Cisco.com to upgrade the switch software, read this section for important information:

"Finding the Software Version and Feature Set Running on the Switch" section

"Deciding Which Files to Download from Cisco.com" section

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

"Upgrading a Switch by Using the CLI" section

"Recovering from a Software Failure" section


Caution A bootloader upgrade occurs if you are upgrading the switch from a noncryptographic image to cryptographic image, regardless of the current noncryptographic Cisco IOS Release that is running on the switch. The bootloader can take up to 30 seconds to upgrade. Do not power cycle the switch while you are copying this image to the switch. If a power failure occurs when you are copying this image to the switch, call Cisco Systems immediately.

When you upgrade a switch, the switch continues to operate while the new software is copied to flash memory. If flash memory has enough space, the new image is copied to the selected switch but does not replace the running image until you reboot the switch. If a failure occurs during the copy process, you can still reboot your switch by using the old image. If flash memory does not have enough space for two images, the new image is copied over the existing one. Features provided by the new software are not available until you reload the switch.

If a failure occurs while copying a new image to the switch, and the old image has already been deleted, see the "Recovering from Corrupted Software" section in the "Troubleshooting" chapter of the software configuration guide.

Finding the Software Version and Feature Set Running on the Switch

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 displays C3550-ipbase9-mz for the IP services image (formerly known as the EMI) or C3550-ipbase-mz for the IP base image (formerly known as the SMI).


Note Although the show version output always shows the software image running on the switch (Layer 2 only or Layer 2 and Layer 3), the model name shown at the end of this display is the factory configuration (SMI or 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 Download from Cisco.com

Cisco IOS Release 12.2(25)SEA and earlier referred to the image that provides Layer 2+ features and basic Layer 3 routing features as the standard multilayer image (SMI). The image that provides full Layer 3 routing features and advanced features 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. Table 3 lists the different file-naming conventions before and after Cisco IOS Release 12.2(25)SEB.

Table 3 Cisco IOS Image File Naming Convention

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

c3550-i9q3l2 (SMI)

c3550-ipbase-mz

c3550-i5q3l2-tar (EMI)

c3550-ipservices-mz

c3550-i9k91l2q3-tar (SMI)

c3550-ipbasek9-mz

c3550-i5k91l2q3-tar (EMI)

c3550-ipservicesk9-mz


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

Table 4 lists the software filenames for this release. These files are posted on Cisco.com.

Table 4 Cisco IOS Software Files for Catalyst 3550 Switches 

Filename

Description

c3550-ipbase-tar.122-50.SE5.tar

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

c3550-ipservices-tar.122-50.SE5.tar

Cisco IOS IP services image and device manager files.
This image has Layer 2+ and full Layer 3 features.

c3550-ipbasek9-tar.122-50.SE5.tar

Cisco IOS IP base cryptographic image and device manager files.
This image has the Kerberos, Secure Shell (SSH), Layer 2+, and basic Layer 3 routing features.

c3550-ipservicesk9-tar.122-50.SE5.tar

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


Catalyst 3550 switches are supported by either the IP base image or the IP services image. All Catalyst 3550 Gigabit Ethernet switches are shipped with the IP services image installed. Catalyst 3550 Fast Ethernet switches are shipped with either the IP base image or the IP services image installed. After initial deployment, you can order the IP services Image Upgrade kit to upgrade the Catalyst 3550 Fast Ethernet switches from the IP base image to the IP services image.

Archiving Software Images

Before upgrading your switch software, make sure that you have archived copies of the current Cisco IOS release and the Cisco IOS release to which you are upgrading. You should keep these archived images until you have upgraded all devices in the network to the new Cisco IOS image and until you have verified that the new Cisco IOS image works properly in your network.

Cisco routinely removes old Cisco IOS versions from Cisco.com. See Product Bulletin 2863 for more information:

http://www.cisco.com/en/US/products/sw/iosswrel/ps5187/prod_bulletin0900aecd80281c0e.html

You can copy the bin software image file on the flash memory to the appropriate TFTP directory on a host by using the copy flash: tftp: privileged EXEC command.


Note Although you can copy any file on the flash memory to the TFTP server, it is time consuming to copy all of the HTML files in the tar file. We recommend that you download the tar file from Cisco.com and archive it on an internal host in your network.


You can also configure the switch as a TFTP server to copy files from one switch to another without using an external TFTP server by using the tftp-server global configuration command. For more information about the tftp-server command, see the "Basic File Transfer Services Commands" section of the Cisco IOS Configuration Fundamentals Command Reference, Release 12.2 at this URL:

http://www.cisco.com/en/US/products/sw/iosswrel/ps1835/products_command_reference_book09186a00800811e0.html

Upgrading a Switch by Using Device Manager or Network Assistant

You can upgrade switch software by using the device manager or Network Assistant. From the feature bar, choose Administration > Software Upgrade. 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 Catalyst 3550 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. This procedure requires a configured TFTP server.


Caution A bootloader upgrade occurs if you are upgrading the switch from a noncryptographic image to a cryptographic image, regardless of the current noncryptographic Cisco IOS release that is running on the switch. The bootloader can take up to 30 seconds to upgrade. Do not power cycle the switch while you are copying this image to the switch. If a power failure occurs when you are copying this image to the switch, call Cisco Systems immediately.

To download software, follow these steps:


Step 1 Use Table 4 to identify the file that you want to download.

Step 2 Download the software image file.

Go to this URL, and follow the instructions to register on Cisco.com and download the appropriate files:

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

To download the IP base image (formerly known as the SMI) and IP services image (formerly known as the EMI) files, select Catalyst 3550 software.

To obtain authorization and to download the cryptographic software files, select Catalyst 3550 3DES Cryptographic Software.

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, see Appendix B in the Catalyst 3550 Multilayer Switch Software Configuration Guide.)

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

Step 5 Verify your VLAN 1 configuration by using the show interfaces vlan 1 privileged EXEC command, and verify that VLAN 1 is part of the same network as the TFTP server. (See the Internet address is line near the top of the display.)

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 using this privileged EXEC command:

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 been 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/c3550-i5q3l2-tar.122-50.SE1.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.

Upgrading with a Nondefault System MTU Setting

If the switch was running Cisco IOS Release 12.1(8)EA1c or earlier and you had used the system mtu global configuration command to configure a nondefault system maximum transmission unit (MTU) size on your switch, follow these steps to upgrade your switch to Cisco IOS Release 12.1(11)EA1 or later:


Step 1 Upgrade the Cisco IOS software to Cisco IOS Release 12.1(11)EA1 or later.

Step 2 If a system MTU size of greater than 2000 is configured on a Gigabit Ethernet switch (Catalyst 3550-12T or Catalyst 3550-12G) use the system mtu global configuration command to set it to the maximum supported MTU size. The maximum allowable system MTU for Catalyst 3550 Gigabit Ethernet switches
is 2000 bytes.

Step 3 Save the running configuration by entering the copy running-config startup-config privileged EXEC command.

Step 4 Reload the switch with the new Cisco IOS software.

Step 5 When the switch comes back up with Cisco IOS Release 12.1(11)EA1 or later, reload the switch a second time by using the reload privileged EXEC command so that the system mtu command takes effect.


Recovering from a Software Failure

If the software fails, you can reload the software. For detailed recovery procedures, see the "Troubleshooting" chapter in the software configuration guide.

Installation Notes

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

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

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

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

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

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

For a list of supported hardware, see the "Hardware Supported" section.

New Software Features

There are no new software features in this release.

Limitations and Restrictions

You should review this section before you begin working with the switches. These are known Cisco IOS 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.

Cisco IOS Limitations and Restrictions

These sections describe the Cisco IOS limitations for features on the switch:

"IEEE 802.1x" section

"ACLs" section

"Connected Devices" section

"Configuration" section

"DHCP" section

"EtherChannel" section

"HSRP" section

"IGMP" section

"IP" section

"MAC Addressing" section

"MIBs" section

"Multicasting" section

"Port Security" section

"QoS" section

"Routing" section

"SNMP" section

"SPAN and RSPAN" section

"Spanning Tree" section

"VLAN" section

IEEE 802.1x

These are IEEE 802.1x limitations:

When an IEEE 802.1x-authenticated client is disconnected from an IP phone, hub, or switch and does not send an EAPOL-Logoff message, the switch interface does not transition to the unauthorized state. If this happens, it can take up to 60 minutes for the interface to transition to the unauthorized state when the re-authentication time is the default value (3600 seconds).

The workaround is to change the number of seconds between re-authentication attempts by using the dot1x timeout re-authperiod seconds global configuration command. (CSCdz38483)

On a switch running Cisco IOS Release 12.1(12c)EA1 or later, if the switch MTU value is set to a value greater than 1500 and the authentication server and the intermediate devices are not configured with a compatible MTU value, IEEE 802.1x authentication with EAP-Transparent LAN Services (TLS) might fail.

The workaround is to reset the switch MTU value to the default value or to configure the same MTU value on the switch, the authentication server, and the intermediate devices. (CSCea05682)

ACLs

These are access control list (ACL) limitations. For ACL limitations with quality of service (QoS), see the "QoS" section.

If you apply a large ACL and it fills the entire ternary content addressable memory (TCAM), the MVR IP multicast data packets are sent to the switch CPU and are not forwarded to the MVR receiver ports.

There is no workaround. (CSCdx80751)

If the output from the show tcam inacl 1 statistics privileged EXEC command shows that the TCAM is not full and you are applying an ACL, this system message might appear:

%FM-3-UNLOADING: Unloading input vlan label 1 feature from all TCAMs

There is no workaround. (CSCea25658)

Connected Devices

These are limitations related to connections with specific devices:

When you configure an EtherChannel between a Catalyst 3550 switch and a Catalyst 1900 switch, some of the Catalyst 3550 links in the EtherChannel might go down, but one link in the channel remains up, and connectivity is maintained.

The workaround is to disable the Port Aggregation Protocol (PAgP) on both devices by using the channel-group channel-group-number mode on interface configuration command. PAgP negotiation between these two devices is not reliable. (CSCdt78727)

If a switch and a Cisco redundant power system (RPS) 300 or 675 are connected to different power sources and the switch power supply fails, the Cisco RPS supplies power to the switch. However, after the switch power supply is restored, the Cisco RPS continues providing power to the switch.

When the switch stops receiving power from the Cisco RPS and uses its own power supply to power the switch, pressing the Standby/Active button on the Cisco RPS might cause the switch to reload.


Note We recommend that you connect the switch and the Cisco RPS to the same power source. For more information, see the Cisco RPS installation guide.


There is no workaround. (CSCdx81023)

When you insert a GigaStack GBIC in a GBIC module slot, the CPU utilization increases by 6 percent. This increase occurs for each GigaStack GBIC added to the switch. Other types of GBICs do not cause additional CPU utilization.

There is no workaround. (CSCdx90515)

When the link between a device with an AC power supply and a Catalyst 3550-24PWR switch is 10 Mb/s and half duplex, and the AC power supply is turned off, the switch is in the error-disabled state.

The workaround is remove the AC power supply, disconnect the Ethernet cable, and then reconnect the Ethernet cable. This ensures that the switch uses inline power. (CSCdz16265)

The Catalyst 3550 switch does not adjust the power allocation based on the IEEE class of the power device. When an IEEE powered-compliant device is connected to a switch, it allocates 15 W (the default) to the port.

There is no workaround. (CSCdz37516)

When a Catalyst 3550 switch is connected to a three-port Gigabit Ethernet module in a Cisco 12000 Gigabit Switch Router (GSR) that is configured for Ethernet over Multiprotocol Label Switching (EoMPLS), the switch does not reliably send frames to the GSR.

The workaround is to configure the Catalyst 3550 Gigabit Ethernet interface with the spanning-tree portfast interface configuration command. (CSCea04746)

If a cable on an ingress interface is disconnected, an Alteon A184 cannot detect when a 1000BASE-X link between two Catalyst 3550 switches is down.

There is no workaround. (CSCea09786)

When three or more Catalyst 3550-24PWR switches are connected through GigaStack GBICs, you can access all the VLANs on the uplink switch, but you can only access VLAN 1 on the other switches.

The workaround is to enter the switchport mode trunk interface configuration command on all of the GigaStack interfaces and to do one of these:

Use the shutdown and then the no shutdown interface configuration commands on the ports.

Save the switch configuration by using the copy running-config startup-config privileged EXEC command, and reload all the switches. (CSCec86258)

The undersize error counter is incrementing when no undersize packets are present. This condition occurs on IEEE 802.1Q tunnel ports connected to a Nortel or an Alteon Load Balancer.

There is no known workaround. (CSCed73388)

If four switches are connected in a cascaded stack through the GigaStack GBICs, the link between the second and third switches goes down, and then the GBICs on the second and third switches are reconnected, the GBIC LEDs flash amber, and the ports take approximately 1 minute to come up. Some of the GBIC ports might not come up.

There is no workaround. (CSCef17198)

The Cisco RPS 300 redundant power system supports the Catalyst 3550 multilayer switch and provides redundancy for up to six connected devices until one of these devices requires backup power. If a connected device has a power failure, the Cisco RPS 300 immediately begins supplying power to that device and sends status information to other connected devices that it is no longer available as a backup power source. As described in the device documentation, when the RPS LED on the switch is amber, the Cisco RPS 300 is connected but down. However, this might merely mean that the Cisco RPS 300 is in standby mode. Press the Standby/Active button on the Cisco RPS 300 to put it into active mode. You can view the Cisco RPS 300 status through the CLI by using the show rps privileged EXEC command. For more information, see the Cisco RPS 300 documentation.

Configuration

These are configuration limitations:

When changing the link speed of a Gigabit Ethernet port from 1000 to 100 Mb/s, there is a slight chance that the port will stop forwarding packets.

The workaround is to shut down the port, and to re-enable it by using the shutdown and no shutdown interface configuration commands. (CSCds84279)

When you use the no interface port-channel global configuration command to remove an EtherChannel group, the ports in the port group change to the administratively down state.

The workaround, when you remove an EtherChannel group, is to enter the no shutdown interface configuration command on the interfaces that belonged to the port group to bring them back on line. (CSCdt10825)

In the show interface interface-id privileged EXEC command output, the output buffer failures field shows the number of packets lost before replication, whereas the packets output field shows the successfully transmitted packets after replication. To determine actual discarded frames, multiply the output buffer failures by the number of VLANs on which the multicast data is replicated.

There is no workaround. (CSCdt26928)

Remote Monitoring (RMON) collection functions on physical interfaces, but it is not supported on EtherChannels and Switched Virtual Interfaces (SVIs). (CSCdt36101)

If a switch stack contains both Catalyst 3550 switches and Catalyst 2900 XL or Catalyst 3500 XL switches, Cross-Stack UplinkFast (CSUF) is not enabled if the management VLAN on the Catalyst 2900 XL or 3500 XL switches is changed to a VLAN other than VLAN 1 (the default).

The workaround is to make sure that the management VLAN of all Catalyst 2900 XL or 3500 XL switches in the stack is set to VLAN 1. (CSCdv79737)

The 5 minute input rate and 5 minute output rate fields in the output of the show interfaces privileged EXEC command show both rates as 0 bits/sec. If you enter the show interfaces command more than once, these fields might show values greater than 0 bits/sec.

There is no workaround. (CSCdz06305)

Performing an extended ping from one interface to another interface on the same switch can cause high CPU utilization. This can occur when a large number of ping packets are sent and received and is the expected behavior.

The workaround is to not perform a ping from one interface to another on the same switch. (CSCea19301)

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)

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

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

Storm control or traffic suppression (configured by using the storm-control {broadcast | multicast | unicast} interface configuration command) is supported only on physical interfaces. It is not supported on EtherChannel port channels, even though you can enter these commands through the CLI.

When system jumbo MTU size is configured on a switch and the egress ports can support jumbo frames, the egress SPAN jumbo frames are not forwarded to the SPAN destination ports.

There is no workaround. (CSCsj21718)

DHCP

This is the DHCP limitation:

The DHCP option-82 format on the Catalyst 3550 switch is inconsistent with other Cisco switches. When the Catalyst 3550 switch is used as the relay agent with DHCP snooping and the option-82 feature using the VLAN-module-port (vlan-mod-port) format, the switch does not assign the correct value to the port identifier (circuit ID suboption). The value is offset by 1 from the actual interface module- and port-number values. The circuitID/port-identifier for Fast Ethernet and Gigabit Ethernet interfaces also have the same module-number but different port-number values. For example, on a Catalyst 3550-24 switch, fastethernet0/1 is reported as module 0/port 0 and gigabitethernet0/1 is reported as module 0/port 24.

There is no workaround. (CSCed29525)

EtherChannel

This is the EtherChannel limitations:

The switch might display tracebacks similar to this example when an EtherChannel interface port-channel type changes from Layer 2 to Layer 3 or the reverse:

15:50:11: %COMMON_FIB-4-FIBNULLHWIDB: Missing hwidb for fibhwidb Port-channel1 (ifindex 
1632) -Traceback= A585C B881B8 B891CC 2F4F70 5550E8 564EAC 851338 84AF0C 4CEB50 859DF4 
A7BF28 A98260 882658 879A58

There is no workaround. (CSCsh12472)

HSRP

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

After the no interface tunnel0 global configuration command is entered to remove the tunnel interface, the output from the show running-config privileged EXEC command still shows the tunnel interface that was removed.

This can occur if HSRP interface tracking is configured on another interface to track a tunnel interface, if the no interface command was entered before the HSRP tracking configuration was removed, or if the no standby tunnel0 global configuration command was entered on the other interface to disable tracking.

These are the workarounds:

Before removing the tunnel interface from the configuration, remove the HSRP interface tracking commands in the configuration that specify the tunnel interface.

Use the no standby track global configuration command without specifying an interface to disable HSRP tracking. (CSCdz66450)

IGMP

These are the IGMP limitations:

Internet Group Management Protocol (IGMP) packets classified by QoS to map the DSCP value and the class of service (CoS) value in a QoS policy map might modify only the DSCP property and leave the CoS value at zero.

There is no workaround. (CSCdt27705)

When IGMP filtering is enabled and you use the ip igmp profile global configuration command to create an IGMP filter, reserved multicast addresses cannot be filtered. Because IGMP filtering uses only Layer 3 addresses to filter IGMP reports and due to mapping between Layer 3 multicast addresses and Ethernet multicast addresses, reserved groups (224.0.0.x) are always allowed through the switch. Aliased groups can also leak through the switch. For example, if a user is allowed to receive reports from group 225.1.2.3, but not from group 230.1.2.3, aliasing causes the user to receive reports from 230.1.2.3. Aliasing of reserved addresses means that all groups of the form y.0.0.x are allowed through.

There is no workaround. (CSCdv73626)

If you use the ip igmp max-groups interface configuration command to set the maximum number of IGMP groups for an interface to 0, the port still receives group reports from reserved multicast groups (224.0.0.x) and their Layer 2 aliases (y.0.0.x).

There is no workaround. (CSCdv79832)

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 command is only applicable to non-IP multicast traffic.

There is no workaround. (CSCee16865)

After you configure a switch to join a multicast group by entering the ip igmp join-group group-address interface configuration command, the igmp join sent by the client might be suppressed. If this happens, the switch port where the client is connected might be removed from the IGMP snooping forwarding table.

Use one of these workarounds:

Cancel membership in the multicast group by using the no ip igmp join-group group-address interface configuration command on an SVI.

Disable IGMP snooping on the VLAN interface by using the no ip igmp snooping vlan vlan-id global configuration command. (CSCeh90425)

IP

This is the IP limitation:

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)

MAC Addressing

These are MAC address limitations:

After a MAC address is relearned on a new interface, traffic might not be immediately forwarded to the MAC addresses.

There is no workaround. (CSCdz75459)

The switch uses the same MAC address for all VLAN interfaces. If the destination MAC address in a packet is the same as the MAC address of the VLAN interface, and the VLAN interface for that VLAN is shut down or does not exist, the switch drops the packet.

There is no workaround. (CSCed12004)

If packets with a bad cyclic redundancy check (CRC) are received on a port, the switch might learn the source MAC address of the bad packet.

There is no workaround. (CSCef15178)

MIBs

These are MIB limitations:

When you access the CISCO-STACK-MIB portTable, the mapping might be off by one from the mapping given by the switch. The objects in this table are indexed by two numbers: portModuleIndex and portIndex. The allowable values for portModuleIndex are 1 through 16. Because 0 is not an allowable value, the value 1 represents module 0.

The workaround is to use the value 1 to represent module 0. (CSCdw71848)

The Catalyst 3550 switch only supports the read operation in the sysClearPortTime MIB object (.1.3.6.1.4.1.9.5.1.1.13) in the CISCO-STACK-MIB. Use the clear counters privileged EXEC command to clear the counters.

There is no workaround. (CSCdz87897)

Multicasting

These are the multicasting limitations:

Modifying a multicast boundary access list does not prevent packets from being forwarded by any multicast routes that were in existence before the access list was modified if the packets arriving on the input interface do not violate the boundary. However, no new multicast routes that violate the updated version of the multicast boundary access list are learned, and any multicast routes that are in violation of the updated access list are not relearned if they age out.

After updating a multicast boundary, the workaround is to use the clear ip mroute privileged EXEC command to delete any existing multicast routes that violate the updated boundary. (CSCdr79083)

The show ip mroute count privileged EXEC command might display incorrect packet counts. In certain transient states (for example, when a multicast stream is forwarded only to the CPU during the route-learning process and the CPU is programming this route into the hardware), a multicast stream packet count might be counted twice.

The workaround is to not trust the counter during this transient state. (CSCds61396)

In IP multicast routing and fallback bridging, certain hardware features are used to replicate packets for the different VLANs of an outgoing trunk port. If the incoming speed is line rate, the outgoing interface cannot duplicate that speed (because of the replication of the packets). As a result, certain replicated packets are dropped.

There is no workaround. (CSCdt06418)

Multicast router information appears in the show ip igmp snooping mrouter privileged EXEC command output when IGMP snooping is disabled. Multicast VLAN Registration (MVR) and IGMP snooping use the same commands to display multicast router information. In this case, MVR is enabled, and IGMP snooping is disabled.

There is no workaround. (CSCdt48002)

When you use the ip pim spt-threshold infinity interface configuration command, you want all sources for the specified group to use the shared tree and not use the source tree. However, the switch does not automatically start to use the shared tree. No connectivity problem occurs, but the switch continues to use the shortest path tree for multicast group entries already installed in the multicast routing table.

The workaround is to enter the clear ip mroute privileged EXEC command to force the change to the shared tree. (CSCdt60412)

Configuring too many multicast groups might result in an extremely low memory condition and cause the software control data structure to go out of sync, causing unpredictable forwarding behavior. The memory resources can only be recovered by entering the clear ip mroute privileged EXEC command.

The workaround is to not configure more than the recommended number of multicast routes on the switch. (CSCdt63480)

If the number of multicast routes configured on the switch is greater than the switch can support, it might run out of available memory, which can cause it to reboot. This is a limitation in the platform-independent code.

The workaround is to not configure the switch to operate with more than the maximum number of supported multicast routes. You can use the show sdm prefer and show sdm prefer routing privileged EXEC commands to view approximate maximum configuration guidelines for the current SDM template and the routing template. (CSCdt63354)

Multicast traffic can be temporarily lost when a link comes up in a redundant network and causes the reverse path forwarding (RPF) to change. This only occurs when there are multiple paths between the rendezvous point (RP) and the multicast source.

There is no workaround. (CSCdw27519)

When the switch receives multicast traffic and IGMP join for requests a multicast group at the same time and it begins to forward the multicast packets, some of the packets might be dropped.

There is no workaround. (CSCdy80326)

When one Fast Ethernet port on a switch (Switch A) is connected to a packet generator, and another Fast Ethernet port on the switch is connected to a Gigabit Ethernet interface on another switch (Switch B), multicast traffic sent from Switch A to Switch B is incorrectly counted. The output from the show mls qos interface interface-id statistics command for the Gigabit Ethernet interface is incorrect.

There is no workaround. (CSCee19574)

Port Security

These are port security limitations:

If IP source guard and port security are both enabled on a port, and the port is flooded with a large number of unknown MAC addresses, the CPU utilization becomes very high. (CSCeg53423)

If a port is configured as a secure port with the violation mode as restrict, the secure ports might process packets even after maximum limit of MAC addresses is reached, but those packets are not forwarded to other ports.

There is no workaround. (CSCdw02638)

Certain combinations of features create conflicts with the port security feature. In Table 5, No means that port security cannot be enabled on a port if the referenced feature is also running on the same port. Yes means that both port security and the referenced feature can be enabled on the same port at the same time. A dash means not applicable.

Table 5 Port Security Compatibility with Other Features 

Type of Port
Compatible with Port Security

DTP1 port2

No

Trunk port

Yes

Dynamic-access port3

No

Routed port

No

SPAN source port

Yes

SPAN destination port

No

EtherChannel

No

Tunneling port

Yes

Protected port

Yes

IEEE 802.1x port

Yes

Voice VLAN port4

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.


QoS

These are QoS limitations:

If you assign both tail-drop threshold percentages to 100 percent by using the wrr-queue threshold interface configuration command and display QoS information for this interface by using the show mls qos interface statistics privileged command, the drop-count statistics are always zero even if the thresholds were exceeded. To display the total number of discarded packets, use the show controllers ethernet-controllers interface-id privileged EXEC command. In the display, the number of discarded frames includes the frames that were dropped when the tail-drop thresholds were exceeded.

The behavior of a software access control list (ACL) with QoS is different from a hardware ACL with QoS. On the Catalyst 3550 switch, when the QoS hardware rewrites the DSCP of a packet, the rewriting of this field happens before software running on the CPU examines the packet, and the CPU sees only the new value and not the original DSCP value.

When the security hardware ACL matches a packet on input, the match uses the original DSCP value. For output security ACLs, the security ACL hardware should match against the final, possibly changed, DSCP value as set by the QoS hardware. Under some circumstances, a match to a security ACL in hardware prevents the QoS hardware from rewriting the DSCP and causes the CPU to use the original DSCP.

If a security ACL is applied in software (because the ACL did not fit into hardware, and packets were sent to the CPU for examination), the match probably uses the new DSCP value as determined by the QoS hardware, whether or not the ACL is applied at the receiving or sending interface. When packets are logged by the ACL, this problem can also affect whether or not a match is logged by the CPU, even if the ACL fits into hardware and the permit or deny filtering was completed in hardware.

To avoid these issues, whenever the switch rewrites the DSCP of any packet to a value different from the original DSCP, security ACLs should not test against DSCP values in any of their access control elements (ACEs), whether or not the ACL is being applied to an IP access group or to a VLAN map. This restriction does not apply to ACLs used in QoS class maps.

If the switch is not configured to rewrite the DSCP value of any packet, it is safe to match against DSCP in ACLs used for IP access groups or for VLAN maps because the DSCP does not change as the packet is processed by the switch.

The DSCP field of an IP packet encompasses the two fields that were originally designated precedence and type of service (ToS). Statements relating to DSCP apply equally to either IP precedence or IP ToS. (CSCdt94355)

Ternary content addressable memory (TCAM) generation might fail when there are multiple ACLs in a policy-map. If you add an entry that checks TCP flags to an access list that is used for QoS classification, the system might report that a hardware limitation has been reached for the policy map. This can occur when the policy map already contains several other access list entries that check different TCP flags or that check TCP or User Datagram Protocol (UDP) port numbers by using an operation different from equal (eq), such as not equal (ne), less than (lt), greater than (gt), or range. When the hardware limitation is reached, the service-policy input policy-map-name interface configuration command is removed from the running configuration of the interface.

Checking for TCP flags and TCP/UDP port numbers using operators other than eq share some of the same hardware resources. The switch supports no more than six checks within a single policy map. An identical check repeated in multiple entries in the same policy map counts as a single instance. If this limit is reached during a TCP or a UDP port number check, the software can often work around the problem by allocating extra entries in the TCAM. There is no workaround if the limit is reached during a check against the TCP flags in the packet. Similar checks in a port ACL applied to the same physical interface as the policy map also count toward the limit.

Because these resources are allocated on a first-come, first-serve basis, rearranging the order of ACLs within a policy map or the order of entries within a single ACL, placing the TCP flags checks as early as possible, might enable the policy map to be loaded into the hardware.

Similar limits apply for any combination of input VLAN maps, input router ACLs, output VLAN maps, and output router ACLs that share the same VLAN label. The switch supports eight checks for all features on the same VLAN label. When the limit is reached, the system might forward packets by using the CPU rather than through hardware, greatly reducing system performance. To determine the VLAN label assigned to a VLAN or interface on input or output, use the show fm vlan or show fm interface privileged EXEC commands. Then use the show fm vlan-label privileged EXEC command to determine which set of features (input VLAN map, input router ACL, output VLAN map, or output router ACL) share this label.

These are the workarounds:

Re-arrange the order of classes within the policy map and the order of entries within the individual access lists in the policy map or within any IP port ACL applied to the interface so that checks for TCP flags are made as early as possible within the policy map. You can also re-arrange the order of the individual ACLs within a VLAN map and the order of the individual entries in a security ACL.

Add an extra entry to the front of an ACL that checks for the same TCP flags that are checked later on in the ACL. If the first entry of the ACL already matches only the TCP protocol, you can duplicate the entry and add a check for the appropriate TCP flags.

Reduce the number of different combinations of TCP flags being tested.

If the other workarounds fail, avoid combining any check against the TCP flags with gt, lt, ne, or range checks within the policy map and port ACL configured on the interface or within the VLAN maps and router ACLs that share the same VLAN label. (CSCdx24363)

If you apply an ACL to an interface that has a QoS policy map attached and the ACL is configured so that the packet should be forwarded by the CPU or if the configured ACL cannot fit into the ternary content addressable memory (TCAM), all packets received from this interface are forwarded to the CPU. Because traffic forwarded to the CPU cannot be policed by the policer configured on the interface, this traffic is not accurately rate-limited to the configured police rate.

The workaround, when QoS rate limiting is configured on an interface, is to configure applied ACLs so that packets are not forwarded by the CPU or reduce the number of ACEs in the ACL so that it can fit into the TCAM. (CSCdx30485)

If you create a policy map by using the policy-map policy-map-name global configuration command, enter the class class-map-name policy-map configuration command, and then immediately exit from the policy-map class configuration mode, the policy map does not show its class-map association.

The workaround is to enter another command (such as the police, trust, or set policy-map class configuration commands) after entering the class class-map-name policy-map configuration command. (CSCdx81650)

If a switch configuration contains a large ACL and a per-port per-VLAN policy map and both are attached to two interfaces, when you are copying it to the running configuration, this process might fail because the switch runs out of memory.

These are the workarounds:

Copy the new configuration file to the config.txt file, and reboot the switch.

Save the configuration file as two files: one containing only the ACL configuration and one containing the rest of the configuration (including the QoS and interface configuration). Add the first configuration file to the running-configuration file, and then add the second file to the running-configuration file. (CSCdz54115)

If you are configuring a policy map on an interface by using named ACLs and the policy map has 13 named ACLs that include deny statements, these messages might appear when you add an ACL:

QoS: Programming TCAM failed: Unsuccessful ACL merge
 Service Policy attachment failed
 Service Policy xxxx not attached
QM-4-HARDWARE_NOT_SUPPORTED: Hardware limitation has reached for policymap xxxx

Use one of these workarounds:

Use numbered ACLs.

Do not use deny statements because the end of an ACL has an implicit deny statement. (CSCec46594)

Catalyst 3550 switches do not take into account the Preamble and IFG when rate limiting traffic, which could result in a slightly inaccurate policing rate on a long burst of small frames, where the ratio of the Preamble and IFG to frame size is more significant. This should not be an issue in an environment where the frames are a mix of different sizes.

Certain combinations of features create conflicts with the port security feature. In Table 5, No means that port security cannot be enabled on a port if the referenced feature is also running on the same port. Yes means that both port security and the referenced feature can be enabled on the same port at the same time. A dash means not applicable.

Routing

These are routing limitations:

Open Shortest Path First (OSPF) path costs and Interior Gateway Routing Protocol (IGRP) metrics are incorrect for switch virtual interface (SVI) ports.

The workaround is to configure the bandwidth of the SVI manually by using the bandwidth interface configuration command. Changing the bandwidth of the interface changes the routing metric for the routes when the SVI is used as an sending interface. (CSCdt29806)

The dec keyword is not supported in the bridge bridge-group protocol global configuration command. If two Catalyst 3550 switches are connected to each other through an interface that is configured for IP routing and fallback bridging, and the bridge group is configured with the bridge bridge-group protocol dec command, both switches act as if they were the spanning-tree root. Therefore, spanning-tree loops might be undetected.

There is no workaround. (CSCdt63589)

When the switch is operating with equal-cost routes and it is required to learn more unicast routes than it can support, the CPU might run out of memory, and the switch might fail.

The workaround is to remain within the documented recommended and supported limits. (CSCdt79172)

If a Catalyst 3550 switch is connected to two routers (Router 1 and Router 2) in this topology:

The link between Router 1 and the switch is a BVI (bridge virtual interface) that belongs to two VLANs (VLAN 100 and VLAN 110) and uses one IP address. The IP subnet for the BVI is the same for both VLANs. The ports in both VLANs operate as Layer 2 interfaces. An SVI with an IP address is configured only on VLAN 100.

The link between Router 2 and the switch is an IP interface that only belongs to VLAN 110.

IP connectivity then exists between Router 1 and the switch. There is no IP connectivity between Router 2 and the switch.

The workaround is to configure another SVI with an IP address on the Catalyst 3550 switch that would be reachable from Router 2. (CSCdy82042)

When the switch has many routes that use loadsharing among multiple next hops, some of the routes might not loadshare but instead pick only one of the next hops for forwarding all packets on that route. This happens when the portion of the adjacency RAM that has been allotted for multipath routes has been used up.

There is no workaround. (CSCed22152)

Packets received from media types that require SNAP encapsulation of IPv4 packets require the switch to forward SNAP-encapsulated packets. Layer 2 forwarding of IPv4 in SNAP encapsulation ordinarily takes place in hardware (unless a VLAN map or port ACL contains an IP ACL). However, on the Catalyst 3550 switch, Layer 3 forwarding of IPv4 in SNAP can only be done in software. SNAP-encapsulated IPv4 packets that are directed to the router MAC address or the HSRP group MAC address (if this device is the active router in the HSRP group) are forwarded to the switch CPU, potentially causing high CPU utilization levels.

This is a hardware limitation, and there is no workaround. (CSCed59864)

When multi-VRF-CE is enabled on the switch, the switch does not support the ip directed-broadcast interface configuration command used to enable forwarding of IP-directed broadcasts on an interface.

There is no workaround. (CSCee05670)

When an IP packet with a cyclic redundancy check (CRC) error is received, the per-packet per-Differentiated Service Code Point (DSCP) counter (for DSCP 0) is incremented. Normal networks should not have packets with CRC errors.

There is no workaround. (CSCdr85898)

SNMP

This is the SNMP limitation:

The switch might reload when it is executing the no snmp-server host global configuration command. This is a rare condition that can happen if SNMP traps or informs are enabled and the SNMP agent attempts to send a trap to the host just as it is being removed from the configuration and if the IP address of the host (or the gateway to reach the host) has not been resolved by Address Resolution Protocol (ARP).

The workaround is to ensure that the target host or the next-hop gateway to that host is in the ARP cache (for example, by using a ping command) before removing it from the SNMP configuration. Alternatively, disable all SNMP traps and informs before removing any hosts from the SNMP configuration. (CSCdw44266)

SPAN and RSPAN

These are SPAN and RSPAN limitations:

A Remote Switched Port Analyzer (RSPAN) source session does not forward monitored traffic to the RSPAN destination session if there is an egress SPAN source port in the session with port security or IEEE 802.1x enabled.

There is no workaround. (CSCdy21035)

Not all traffic is properly mirrored by RSPAN when a port is monitored for egress traffic and the RSPAN VLAN is carried through a Layer 2 protocol tunnel to the RSPAN destination switch.

This happens because the MAC addresses for the original packets as well as the mirrored RSPAN packets are all learned on the tunnel VLAN, so the RSPAN traffic is no longer properly segregated on the tunneling switches.

The workaround is to not include any RSPAN VLANs in any Layer 2 protocol tunnels unless the tunnel is dedicated to a single RSPAN VLAN. (CSCdy37188)

Ingress forwarding on a SPAN destination port does not work if there is an egress SPAN source port in the session with port security or IEEE 802.1x enabled.

There is no workaround. (CSCdy44646)

Whenever a single frame is subject to both ingress and egress SPAN, and both the ingress and the egress SPAN are sent to the same SPAN destination port, the egress copy of the spanned frame is sent out the SPAN destination port before the ingress copy of the spanned frame is sent out the SPAN destination port.

There is no workaround. (CSCef97043)

RSPAN does not work when the RSPAN source session and the RSPAN destination session are on the same switch. If an RSPAN source session is configured with a particular RSPAN VLAN and an RSPAN destination session for that RSPAN VLAN is configured on the same switch, then the RSPAN destination session's destination port will not transmit captured packets from the RSPAN source session.

The workaround is to use SPAN instead of RSPAN.(CSCeg08870)

Spanning Tree

These are spanning tree limitations:

If a port on the Catalyst 3550 switch that is running the Multiple Spanning Tree Protocol (MSTP) is connected to another switch that belongs to a different multiple spanning tree (MST) region, the Catalyst 3550 port is not recognized as a boundary port when you start the protocol migration process by using the clear spanning-tree detected-protocols interface interface-id privileged EXEC command. This problem occurs only on the root bridge, and when the root bridge is cleared, the boundary ports are not shown because the designated ports do not receive any bridge protocol data units (BPDUs) unless a topology change occurs. This is the intended behavior.

The workaround is to configure the Catalyst 3550 switch for Per-VLAN spanning-tree plus (PVST+) by using the spanning-tree mode pvst global configuration command bridge, and then change it to MSTP by using the spanning-tree mode mst global configuration command. (CSCdx10808)

When a switch receives a bridge STP bridge protocol data unit (BPDU) from an access port and the egress port is a trunk port, the switch assigns the BPDU a CoS value of 0 instead of 7.

There is no workaround. (CSCdz54043)

CSCef18020

In a switch stack with GigaStack GBICs, cross-stack UplinkFast (CSUF) convergence might be slow when the root port fails.

There is no workaround.

VLAN

These are VLAN limitations:

When a VLAN interface has been disabled and restarted multiple times by using the shutdown and no shutdown interface configuration commands, the interface might not restart following a no shutdown command.

The workaround is to re-enter the shutdown and no shutdown interface configuration commands to restart the interface. (CSCdt54435)

When a large number of VLANs and a large number of trunk ports with allowed VLAN lists are configured on the switch, if you enter the no switchport trunk allowed vlan interface-range command to remove the allowed list for all the trunk ports, the SYS-3-CPUHOG system message might appear.

The workaround is to use the no switchport trunk allowed vlan interface configuration command on each trunk port to remove the allowed list for all the trunk ports. (CSCdx17189)

When 1000 VLANs and more than 40 trunk ports are configured, and the spanning-tree mode changes from MSTP to PVST+ or the reverse, this message appears on the console:

%ETHCNTR-3-RA_ALLOC_ERROR: RAM Access write pool I/O memory allocation failure

There is no workaround. However, we recommend that you reload the switch by using the reload privileged EXEC command. To avoid this problem, configure the system with fewer VLANs and fewer trunk ports, or use the switchport trunk allowed vlan interface configuration command to reduce the number of active VLANs on each trunk port. (CSCdx20106)

If the switch fails for any reason while you are exiting VLAN database configuration mode (accessed by entering the vlan database privileged EXEC command), there is a slight chance that the VLAN database might get corrupted. After resetting from the switch, you might see these messages on the console:

%SW_VLAN-4-VTP_INVALID_DATABASE_DATA: VLAN manager received bad data of type device 
type: value 0 from vtp database 

$SW_VLAN-3-VTP_PROTOCOL_ERROR: VTP protocol code internal error 

The workaround is to use the delete flash:vlan.dat privileged EXEC command to delete the corrupted VLAN database. Then reload the switch by using the reload privileged EXEC command. (CSCdx19540)

When you perform a ping from a VLAN to another VLAN on the same switch, the VLAN counter does not change.

There is no workaround. (CSCdz17863)

On a Catalyst 3550 switch, if you use the command-line interface to repeatedly add and delete a VLAN by entering the vlan vlan-id and no vlan vlan-id global configuration command and the VLAN has secured IEEE 802.1x addresses associated with it and traffic flowing from the secured addresses, the switch might fail.

The workaround is to shut down all ports in the VLAN or to remove the IEEE 802.1x and port-security configurations from all ports in the VLAN before deleting it. (CSCsg19355)

When using the ip source binding global configuration command to associate a static IP source binding with a non existent VLAN that has an ID greater than 1025, this message appears:

%DHCP_SNOOPING-4-IP_SOURCE_BINDING_NON_EXISTING_VLAN_WARNING: IP source binding is configured on non existing vlan 100.

The workaround is to enter the show vlan user EXEC command to verify that the VLAN exists. (CSCsh7417)

Important Notes

These sections describe the important notes related to this software release:

"Cisco IOS Notes" section

"Device Manager Notes" section

Cisco IOS Notes

These are the important Cisco IOS configuration notes related to this release:

In Cisco IOS Release 12.2(44)SE and later, if the switch has interfaces with automatic QoS for voice over IP (VoIP) configured and you upgrade the switch software to Cisco IOS Release 12.2(44)SE (or later), when you enter the auto qos voip cisco-phone interface configuration command on another interface, you might see this message:

AutoQoS Error: ciscophone input service policy was not properly applied
policy map AutoQoS-Police-CiscoPhone not configured

If this happens, enter the no auto qos voip cisco-phone interface command on all interface with this configuration to delete it. Then enter the auto qos voip cisco-phone command on each of these interfaces to reapply the configuration. In Cisco IOS Release 12.2(25)SEC, the implementation for multiple spanning tree (MST) changed from the previous release. Multiple STP (MSTP) is now compliant with the IEEE 802.1s standard. Previous MSTP implementations were based on a draft of the IEEE 802.1s standard.

In Cisco IOS Release 12.1(19)EA1, the implementation for the option-82 subscriber identification changed from the previous release. The new option-82 format uses a different circuit ID and remote ID suboption, vlan-mod-port. The previous version uses the snmp-ifindex circuit ID and the remote ID suboption.

If you have option-82 configured on the switch and you upgrade to Cisco IOS Release 12.1(19)EA1 or later, the option-82 configuration is not affected. However, when you globally enable DHCP snooping on the switch by using the ip dhcp snooping global configuration command, the previous option-82 configuration is suspended, and the new option-82 format is applied. When you globally disable DHCP snooping on the switch, the previous option-82 configuration is re-enabled.

To provide for backward compatibility, you can select the previous option-82 format by using the ip dhcp snooping information option format snmp-ifindex global configuration command when you enable DHCP snooping. When DHCP snooping is globally enabled, option-82 information (in the selected format) is only inserted on snooped VLANs.

For more information about using the previous version of option 82 without enabling DHCP snooping, see the software configuration guide for this release.

In Cisco IOS Release 12.1(14)EA1, the implementation for IEEE 802.1x changed from the previous release. Some global configuration commands became interface configuration commands, and new commands were added.

If you have IEEE 802.1x configured on the switch and you upgrade to Cisco IOS
Release 12.1(14)EA1 or later, the configuration file does not contain the new commands, and
IEEE 802.1x does not operate. After the upgrade is complete, make sure to globally enable
IEEE 802.1x by using the dot1x system-auth-control global configuration command. For more information, see the software configuration guide for this release.

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 2 plus the maximum number of secure addresses allowed on the access VLAN. When the port is connected to a Cisco IP Phone, the telephone requires up to two MAC addresses. The address of the Cisco IP Phone is learned on the voice VLAN, and it might or might not be learned on the access VLAN. Connecting a PC to the Cisco IP Phone requires additional MAC addresses.

If you configure a port ACL on a physical interface on a switch that has VLAN maps or input router ACLs configured, or if you configure a VLAN map or input router ACL on a switch that has port ACLs configured, a CONFLICT message is generated, but the configuration is accepted. The port ACL action has priority on that port over actions in a router ACL or VLAN map applied to the VLAN to which the port belongs.

The result is that packets received on that physical port are permitted or denied based on the port ACL action, without regard to any permit or deny statements in any router ACL or VLAN map. Packets received on other physical ports in the VLAN are still permitted or denied based on any router ACLs or VLAN maps applied to the VLAN. If the port ACL is applied to a trunk port, it overrides any other input ACLs applied to all VLANs on the trunk port.

The default system MTU for traffic on the Catalyst 3550 switch is 1500 bytes. The IEEE 802.1Q tunneling feature increases the frame size by 4 bytes. Therefore, when you configure IEEE 802.1Q tunneling, you must configure all switches in the IEEE 802.1Q network to be able to process maximum frames by increasing the switch system MTU size to at least 1504 bytes. You configure the system MTU size by using the system mtu global configuration command.

When you are configuring a cascaded stack of Catalyst 3550 switches by using the GigaStack GBIC module and want to include more than one VLAN in the stack, be sure to configure all the GigaStack GBIC interfaces as trunk ports by using the switchport mode trunk interface configuration command and to use the same encapsulation method by using the switchport encapsulation {isl | dot1q} interface configuration command. For more information about these commands, refer to the switch command reference for this Cisco IOS release.

If the 1000BASE-T GBIC (WS-G5482) module is not securely inserted, the switch might fail to recognize it or might display an incorrect media type following a show interface privileged EXEC command entry. If this happens, remove and reinsert the GBIC module.

When you configure a dynamic switchport by using the switchport access vlan dynamic interface configuration command, the port might allow unauthorized users to access network resources if the port mode changes from access to trunk through Dynamic Trunking Protocol (DTP) negotiation.

The workaround is to configure the port as a static access port. (CSCdz32330)

Beginning in Cisco IOS Release 12.1(13)EA1, these are the default settings for an IP phone connected to a switch:

The port trust state is to not trust the priority of frames arriving on the IP phone port from connected devices.

The CoS value of incoming traffic is overwritten and set to zero. (CSCdz76948).

If the switch requests information from the Cisco Secure Access Control Server (ACS) and the message exchange times out because the server does not respond, a message similar to this appears:

00:02:57: %RADIUS-4-RADIUS_DEAD: RADIUS server 172.20.246.206:1645,1646 is not 
responding.

If this message appears, check that there is network connectivity between the switch and the ACS. You should also check that the switch has been properly configured as an AAA client on the ACS.

Device Manager Notes

These notes apply to the device manager:

This release supports the same switch cluster compatibilities supported in Cisco IOS Release 12.1(22)EA1. However, you cannot create and manage switch clusters through the device manager. To create and manage switch clusters, use the CLI or Cisco Network Assistant.

When you are prompted to accept the security certificate and you click No, you see only 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)

We recommend this browser setting to speed up the time 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.

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 {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 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

These are the Cisco IOS severity-3 open configuration caveats in this software release:

CSCdx95501

When a community string is assigned by the cluster command switch, you cannot get any dot1dBridge MIB objects by using a community string with a VLAN entity from a cluster member switch.

The workaround is to manually add the cluster community string with the VLAN entity on the member switches for all active VLANs shown in the show spanning-tree summary display. This is an example of such a change, where cluster member 3 has spanning tree on vlan 1-3, and the cluster commander community string is public@es3.

Mbr3(config)# snmp community public@es3@1 RO
Mbr3(config)# snmp community public@es3@2 RO
Mbr3(config)# snmp community public@es3@3 RO

CSCsw68528

On switches running Cisco IOS Release 12.2(44)SE or 12.2(46)SE, when you enter the show mvr interface interface-id members privileged EXEC command to see status of an MVR port, an MVR member port that is not connected always shows as ACTIVE.

The workaround is to use the show mvr interface interface-id or the show mvr members privileged EXEC command. These command outputs show the correct status of an MVR port.

CSCta57846

The switch unexpectedly reloads when copying a configuration file from a remote server or from flash memory containing logging file flash:

The workaround is to enter the logging file flash:filename global configuration command to configure logging to flash instead of copying to flash.

CSCti79385

When a redirect URL is configured for a client on the authentication server and a large number of clients are authenticated, high CPU usage could occur on the switch.

There is no workaround.

Resolved Caveats

"Cisco IOS Caveats Resolved in Cisco IOS Release 12.2(50)SE5" section

"Cisco IOS Caveats Resolved in Cisco IOS Release 12.2(50)SE4" section

"Cisco IOS Caveats Resolved in Cisco IOS Release 12.2(50)SE3" section

"Cisco IOS Caveats Resolved in Cisco IOS Release 12.2(50)SE1" section

"Cisco IOS Caveats Resolved in Cisco IOS Release 12.2(50)SE" section

Cisco IOS Caveats Resolved in Cisco IOS Release 12.2(50)SE5

CSCte14603

A vulnerability in the Internet Group Management Protocol (IGMP) version 3 implementation of Cisco IOS Software and Cisco IOS XE Software allows a remote unauthenticated attacker to cause a reload of an affected device. Repeated attempts to exploit this vulnerability could result in a sustained denial of service (DoS) condition. Cisco has released free software updates that address this vulnerability.

This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20100922-igmp.shtml.

Note: The September 22, 2010, Cisco IOS Software Security Advisory bundled publication includes six Cisco Security Advisories. Five of the advisories address vulnerabilities in Cisco IOS Software, and one advisory addresses vulnerabilities in Cisco Unified Communications Manager. Each advisory lists the releases that correct the vulnerability or vulnerabilities detailed in the advisory. The table at the following URL lists releases that correct all Cisco IOS Software vulnerabilities that have been published on September 22, 2010, or earlier:

http://www.cisco.com/warp/public/707/cisco-sa-20100922-bundle.shtml

Individual publication links are in "Cisco Event Response: Semiannual Cisco IOS Software Security Advisory Bundled Publication" at the following link:

http://www.cisco.com/web/about/security/intelligence/Cisco_ERP_sep10.html

Cisco IOS Caveats Resolved in Cisco IOS Release 12.2(50)SE4

CSCsh59019

Authentication, authorization, and accounting (AAA) fails, preventing authentication and requiring you to recover your password. For example, when you enter the aaa authentication login default group tacacs line global configuration command, AAA fails.

There is no workaround.

CSCsk85192

When you use an access control server (ACS) to enable command authorization, the ACS does not process a copy command ending with a colon (for example, scp:, ftp:, tftp:, flash:).

This problem affects authentication, authorization, and accounting (AAA) authorization:

If the ACS denies a copy command ending with a colon, you can use that command on a switch.

If the ACS permits a copy command ending with a colon, you cannot use that command on a switch.

To workaround is to either deny or permit the copy command without entering any arguments on the ACS.

CSCsy83366

On a switch that is configured for quality of service (QoS), a memory leak occurs when a small portion (about 90 bytes) of the processor memory is not released by the HRPC QoS request handler process.

There is no workaround.

CSCta09189

Packet loss and output drops occur on the egress interface for routed multicast traffic.

This problem occurs when multiple S,G entries time out at the same time and then are re-established at the same time, when multiple Protocol Independent Multicast (PIM) neighbors time out at the same time and then are re-established at the same time, or when multiple high-volume multicast streams are routed through multiple Layer-3 interfaces.

Use one of these workarounds:

Enter the clear ip mroute * EXEC command.

Enter the shutdown interface configuration command followed by the no shutdown interface configuration command on the egress interface.

CSCta87523

When you use Auto Smartports macros on an interface that is connected to an Cisco IP phone, the the quality of service (QoS) configuration for that interface is not completed.

The workaround is to enter the no mls qos vlan-based interface configuration command, and then enable QoS for voice over IP (VoIP) by entering the auto qos voip cisco-phone interface configuration command.

CSCtb10158

A switch can fail when an SNMP process attempts to configure dot1x authentication when it is already configured.

There is no workaround.

CSCtb91572

A switch enters a loop in which it continues to fail after it first has failed while starting, and then has failed again while attempting to recover. This failure loop occurs only after you have entered the archive upload-sw privileged EXEC command to write the configuration to a remote server using Secure Copy Protocol (SCP) and when the connection to the remote server is configured for spanning-tree PortFast.

The workaround is to not use SCP to write to the remote server. Use File Transfer Protocol (FTP) or Trivial File Transfer Protocol (TFTP).

CSCtc39809

A memory leak occurs when there is a stuck in active (SIA) state condition for an Enhanced Interior Gateway Routing Protocol (EIGRP) route.

There is no workaround.

CSCtc43231

A switch does not receive SNMP trap and inform messages from the correct interface after you have entered the snmp-server trap-source loopback0 and snmp-server source-interface informs loopback0 global configuration commands.

There is no workaround.

CSCtc57809

When the no mac address-table static mac-addr vlan vlan-id interface interface-id global configuration command is used to remove a dynamically learned MAC address, the switch fails under these conditions:

The physical interface is in a no shut state.

The MAC address is first dynamically learned and then changed to static.

There is no workaround.

CSCtc70571

When you have configured an output service policy, performing an SNMPWALK on cportQosStatistics causes loops.

There is no workaround.

CSCtc90039

A memory leak occurs on a device that uses Enhanced Interior Gateway Routing Protocol (EIGRP) when the external routes are being exchanged.

The workaround is to stabilize the network to minimize the impact of external route advertisement.

CSCtd17296

When you enter the dot1x pae interface configuration command on a switch access port and then enable an access list in the inbound direction on an ingress switched virtual interface (SVI), the access list does not work, allowing all packets to pass.

The workaround is to enable the access list in the outbound direction on the egress SVI.

CSCtd30053

When you enter the no spanning-tree etherchannel guard misconfig global configuration command, enter the write memory privileged EXEC command, and then restart the switch, the spanning-tree etherchannel guard misconfig global configuration command is saved instead of the no form of this command.

There is no workaround.

CSCtd72456

After you have entered the snmp-server host informs global configuration command to enable SNMP informs on a switch, the switch might fail if you enter the show snmp pending user EXEC command.

There is no workaround. Do not enter the show command when SNMP informs are enabled.

CSCtd73256

A switch fails when you enter the show ip ospf interface user EXEC command and then stop the command output at the this line:

Backup Designated router (ID) xx.x.x.x, Interface address xx.x.x.x

The failure occurs when the Backup Designated Router (BDR) neighbor of the switch is shut down while you press Enter or the spacebar to advance the command output.

When the switch fails, it sends this error message:

Unexpected exception to CPUvector 2000, PC = 261FC60

There is no workaround.

CSCte67201

On a switch that is configured for IP routing and that is running Cisco IOS Release 12.2(50)SE or later, Cisco Express Forwarding (CEF) can use a large amount of memory. The IP RIB Update process uses about 2000 bytes for each prefix that CEF uses.

There is no workaround. You can reduce the memory use by reducing the number of routes the switch processes.

CSCte81321

After you have entered the logging filter global configuration command on a switch to specify a syslog filter module to be used by the Embedded Syslog Manager (ESM), processes logging many system messages retain increasing amounts of processor memory.

The workaround is to enter the no logging filter global configuration command.

Cisco IOS Caveats Resolved in Cisco IOS Release 12.2(50)SE3

CSCso57496

A switch no longer fails when you enter the configure replace privileged EXEC command, and a banner is already present in the switch configuration.

CSCsq24002

Cisco IOS Software contains a vulnerability that could allow an attacker to cause a Cisco IOS device to reload by remotely sending a crafted encryption packet. Cisco has released free software updates that address this vulnerability. This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20090923-tls.shtml.

CSCsq51052

The output of the show ip ssh privileged EXEC command no longer displays SSH Enabled - version 2.99. Instead, a correct SSH version (1.5, 1.99 or 2.0) now appears.

CSCsy15227

Cisco IOS Software configured with Authentication Proxy for HTTP(S), Web Authentication or the consent feature, contains a vulnerability that may allow an unauthenticated session to bypass the authentication proxy server or bypass the consent webpage.

There are no workarounds that mitigate this vulnerability.

This advisory is posted at the following link:

http://www.cisco.com/warp/public/707/cisco-sa-20090923-auth-proxy.shtml

CSCsy07555

Cisco IOS devices that are configured for Internet Key Exchange (IKE) protocol and certificate based authentication are vulnerable to a resource exhaustion attack. Successful exploitation of this vulnerability may result in the allocation of all available Phase 1 security associations (SA) and prevent the establishment of new IPsec sessions.

Cisco has released free software updates that address this vulnerability.

This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20090923-ipsec.shtml

CSCsx70889

Cisco devices running affected versions of Cisco IOS Software are vulnerable to a denial of service (DoS) attack if configured for IP tunnels and Cisco Express Forwarding.

Cisco has released free software updates that address this vulnerability.

This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20090923-tunnels.shtml.

CSCsw45277

Third-party IP phones now automatically power up when reconnected to enabled PoE ports on the switch.

CSCsx49718

Re-authentication now occurs on a port under these conditions:

The port is in single-host mode.

The port is configured with the authentication event no-response action authorize vlan vlan-number command.

An EAPOL start packet is sent to the port.

CSCsy48370

The switch no longer fails when you use the vacant-message line configuration command.

CSCsy72669

If a link failure occurs on a secondary edge port, preemption now occurs after the link comes up.

CSCsy72726

A switch running 12.2(50)SE or later no longer might unexpectedly restart when Auto Smart Ports is enabled and the switch is configured for SSH or the HTTP secure server is enabled by entering the ip http secure-server global configuration command.

CSCsz12381

When open1x authentication and MAC authentication bypass are enabled on a port, an IP phone is connected to the port, and DHCP snooping is enabled on the switch, DHCP traffic is now forwarded on the voice VLAN before open 1x authentication times out and the switch uses MAC authentication bypass to authorize the port.

CSCsz13490

The switch no longer reloads when you enter several key strokes while in interface-range configuration mode.

CSCsz14369

If MAC authentication bypass is enabled and the RADIUS server is not available, the switch now tries to re-authenticate a port after a server becomes available.

CSCsz79652

A memory leak no longer occurs when Cisco Network Assistant is polling the switch and the ip http server or ip http-secure-server global configuration command is enabled.

CSCsz81762

If you enable automatic server testing through the radius-server host ip-address [test username name] global configuration command, the switch no longer sends requests to the RADIUS server if the server is not available.

CSCta32597

A switch no longer fails when a host moves from a dynamically assigned VLAN to a configured VLAN.

CSCta36155

A switch configured with 802.1x and port security on the same ports no longer might inappropriately put the ports into an error-disabled state.

CSCta56469

Moving a PC between two IP Phones without disconnecting either phone from the switch no longer triggers a port-security violation.

CSCta67777

A port security violation error no longer occurs when MAC address sticky learning is enabled on a port and a CDP is enabled on a connected IP Phone.

Cisco IOS Caveats Resolved in Cisco IOS Release 12.2(50)SE1

CSCsb46724

If the connection to a primary AAA server fails, the backup server is now queried for login access.

CSCsr92741

When a TCP packet with all flags set to zero (at the TCP level) is sent to a remote router, the remote (destination) router no longer returns an ACK/RST packet back to the source of the TCP segment.

CSCsy24510

The switch now accepts an encrypted secret password.

Cisco IOS Caveats Resolved in Cisco IOS Release 12.2(50)SE

CSCsk64158

Symptoms: Several features within Cisco IOS software are affected by a crafted UDP packet vulnerability. If any of the affected features are enabled, a successful attack will result in a blocked input queue on the inbound interface. Only crafted UDP packets destined for the device could result in the interface being blocked, transit traffic will not block the interface.

Cisco has released free software updates that address this vulnerability.

Workarounds that mitigate this vulnerability are available in the workarounds section of the advisory. This advisory is posted at the following link: http://www.cisco.com/warp/public/707/cisco-sa-20090325-udp.shtml.

CSCsm27071

A vulnerability in the handling of IP sockets can cause devices to be vulnerable to a denial of service attack when any of several features of Cisco IOS software are enabled. A sequence of specially crafted TCP/IP packets could cause any of the following results:

The configured feature may stop accepting new connections or sessions.

The memory of the device may be consumed.

The device may experience prolonged high CPU utilization.

The device may reload. Cisco has released free software updates that address this vulnerability.

Workarounds that mitigate this vulnerability are available in the "workarounds" section of the advisory. The advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20090325-ip.shtml

CSCsq53204

An access control list (ACL) now correctly filters traffic under these conditions:

A VLAN-based ACL is applied on a VLAN interface

A VLAN-based QoS policy is applied on more than one physical interface

All interfaces with the QoS policy belong to that VLAN

CSCsq26873

The server no longer attempts re-authentication every ten minutes when a switch is configured with the dot1x timeout reauth-period server interface configuration command.

CSCsq67398

Traffic is now forwarded to the interfaces that are configured with static multicast MAC addresses after the switch is reloaded.


Note You cannot configure the static MAC address (unicast or multicast) entries on EtherChannel member interfaces, or add an interface into the EtherChannel if that interface is associated with a static MAC address entry.


CSCsq89564

If the switch uses 802.1x authentication with VLAN assignment, it no longer uses the VLAN assignment with different authorization attempts, such as user authentication or re-authentication.

CSCsr29468

Cisco IOS software contains a vulnerability in multiple features that could allow an attacker to cause a denial of service (DoS) condition on the affected device. A sequence of specially crafted TCP packets can cause the vulnerable device to reload.

Cisco has released free software updates that address this vulnerability.

Several mitigation strategies are outlined in the workarounds section of this advisory.

This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20090325-tcp.shtml

CSCsr50766

When keepalive is disabled on an interface, the interface is no longer put in an error-disabled state when it receives keepalive packets.

CSCsr64007

The Switched Port Analyzer (SPAN) destination port no longer detects IPv6 multicast packets from a VLAN that is not being monitored by SPAN.

CSCsu10065

When SFP ports are configured as status multicast router ports, IPv6 Multicast Listener Discovery (MLD) snooping now works after the switch reloads.

CSCsv38166

The server side of the Secure Copy (SCP) implementation in Cisco IOS software contains a vulnerability that could allow authenticated users with an attached command-line interface (CLI) view to transfer files to and from a Cisco IOS device that is configured to be an SCP server, regardless of what users are authorized to do, per the CLI view configuration. This vulnerability could allow valid users to retrieve or write to any file on the device's file system, including the device's saved configuration and Cisco IOS image files, even if the CLI view attached to the user does not allow it. This configuration file may include passwords or other sensitive information.

The Cisco IOS SCP server is an optional service that is disabled by default. CLI views are a fundamental component of the Cisco IOS Role-Based CLI Access feature, which is also disabled by default. Devices that are not specifically configured to enable the Cisco IOS SCP server, or that are configured to use it but do not use role-based CLI access, are not affected by this vulnerability.

This vulnerability does not apply to the Cisco IOS SCP client feature.

Cisco has released free software updates that address this vulnerability.

There are no workarounds available for this vulnerability apart from disabling either the SCP server or the CLI view feature if these services are not required by administrators.

This advisory is posted at the following link:

http://www.cisco.com/warp/public/707/cisco-sa-20090325-scp.shtml.

CSCsu88168

The switch no longer reloads when the Forwarding Information Base (FIB) adjacency table is added.

CSCsv04836

Multiple Cisco products are affected by denial of service (DoS) vulnerabilities that manipulate the state of Transmission Control Protocol (TCP) connections. By manipulating the state of a TCP connection, an attacker could force the TCP connection to remain in a long-lived state, possibly indefinitely. If enough TCP connections are forced into a long-lived or indefinite state, resources on a system under attack may be consumed, preventing new TCP connections from being accepted. In some cases, a system reboot may be necessary to recover normal system operation. To exploit these vulnerabilities, an attacker must be able to complete a TCP three-way handshake with a vulnerable system.

In addition to these vulnerabilities, Cisco Nexus 5000 devices contain a TCP DoS vulnerability that may result in a system crash. This additional vulnerability was found as a result of testing the TCP state manipulation vulnerabilities.

Cisco has released free software updates for download from the Cisco website that address these vulnerabilities. Workarounds that mitigate these vulnerabilities are available.

This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20090908-tcp24.shtml.

CSCsv30429

A Cisco IP Phone connected to a Catalyst switch no longer becomes unauthorized when it transitions from the data authorization domain to the voice authorization domain.

CSCsv50653

Load sharing no longer fails after you reload the switch.

CSCsv89005

A switch configured with class-based policies that are applied and active on at least one interface no longer might reload or display CPU hog messages during SNMP polling for the ciscoCBQosMIB.

CSCsv91358

When you have entered the vlan dot1q tag native global configuration command to configure a switch to tag native VLAN frames on 802.1Q trunk ports, and you configure a new voice VLAN on an access port, the MAC address of a connected PC is now correctly relearned.

CSCsw30249

When a switch virtual interface (SVI) is configured as unnumbered and is pointing to a loopback interface, the switch no longer fails when the SVI receives a packet.

CSCsw45337

When LLDP is enabled and a voice VLAN is configured, the L2 Priority and DSCP Value fields in the LLDP type, length, and value descriptions (TLVs) are now correctly marked to give the voice traffic the correct DSCP and Layer 2 priority.

CSCsw65548

Switch ports no longer attempt authentication at the interval configured for the port security timer instead of the configured IEEE 802.1x timer.

Documentation Updates

This section provides updates to the product documentation:

"Updates for the Software Configuration Guide" section

"Updates for the Command Reference" section

"Updates for the Regulatory Compliance and Safety Information for the Catalyst 3550 Multilayer Switch" section

"Update to the Hardware Installation Guide" section

"Update to the Getting Start Guide" section

"Update to the System Message Guide" section

Updates for the Software Configuration Guide

The switch does not support the verify user EXEC command.

In the "Power Over Ethernet Ports" section in the "Configuring Interface Characteristics" chapter of the Catalyst 3550 Multilayer Switch Software Configuration Guide, this information is changed:

Catalyst 3550 PoE-capable switch ports automatically supply power to these connected devices (if the switch senses that there is no power on the circuit):

Cisco pre-standard powered devices (such as Cisco IP Phones and Cisco Aironet Access Points)

IEEE 802.3af-compliant powered devices other than a Catalyst 3550 switch, which is not
IEEE 802.3af-compliant.

A powered device can receive redundant power when it is connected to a PoE switch port and to an AC power source.

The documentation updates for the software configuration guide are in the latest version of the book at this URL:

http://www.cisco.com/en/US/docs/switches/lan/catalyst3550/software/release/12.2_44_se/configuration/guide/3550SCG.html

Updates for the Command Reference

For the duplex command, this information in the "Defaults" section is incorrect:

The default is auto.

This is the correct default information:

The default is auto for Fast Ethernet and Gigabit Ethernet ports.

The default is full for the 1000BASE-x (where x is -LX/LH, -SX, -T, and -ZX) GBIC module.

This information is added to the "Usage Guidelines" section:

A Gigabit Ethernet switch interface can operate in half-duplex mode if the duplex mode on the switch is auto, a Gigastack GBIC is in the module slot, and a device is connected to the switch through the GBIC.

Other documentation updates for the command reference are in the latest version of the book at this URL:

http://www.cisco.com/en/US/docs/switches/lan/catalyst3550/software/release/12.2_44_se/command/reference/cr.html

Updates for the Regulatory Compliance and Safety Information for the Catalyst 3550 Multilayer Switch

This information was added to the Regulatory Compliance and Safety Information for the Catalyst 3550 Multilayer Switch:

Statement 361—VoIP and Emergency Calling Services do not Function if Power Fails

Warning


Voice over IP (VoIP) service and the emergency calling service do not function if power fails or is disrupted. After power is restored, you might have to reset or reconfigure equipment to regain access to VoIP and the emergency calling service. In the USA, this emergency number is 911. You need to be aware of the emergency number in your country. Statement 361

Waarschuwing

Voice over IP (VoIP)-service en de service voor noodoproepen werken niet indien er een stroomstoring is. Nadat de stroomtoevoer is hersteld, dient u wellicht de configuratie van uw apparatuur opnieuw in te stellen om opnieuw toegang te krijgen tot VoIP en de noodoproepen. In de VS is het nummer voor noodoproepen 911. U dient u zelf op de hoogte te stellen van het nummer voor noodoproepen in uw land.

Varoitus

Voice over IP (VoIP) -palvelu ja hätäpuhelupalvelu eivät toimi, jos virta katkeaa tai sen syötössä esiintyy häiriöitä. Kun virransyöttö on taas normaali, sinun täytyy mahdollisesti asettaa tai määrittää laitteisto uudelleen, jotta voisit jälleen käyttää VoIP-palvelua ja hätäpuhelupalvelua. Yhdysvalloissa hätänumero on 911. Selvitä, mikä on omassa kotimaassasi käytössä oleva hätänumero.

Attention

Le service Voice over IP (VoIP) et le service d'appels d'urgence ne fonctionnent pas en cas de panne de courant. Une fois que le courant est rétabli, vous devrez peut-être réinitialiser ou reconfigurer le système pour accéder de nouveau au service VoIP et à celui des appels d'urgence. Aux États-Unis, le numéro des services d'urgence est le 911. Vous devez connaître le numéro d'appel d'urgence en vigueur dans votre pays.

Warnung

Bei einem Stromausfall oder eingeschränkter Stromversorgung funktionieren VoIP-Dienst und Notruf nicht. Sobald die Stromversorgung wieder hergestellt ist, müssen Sie möglicherweise die Geräte zurücksetzen oder neu konfigurieren, um den Zugang zu VoIP und Notruf wieder herzustellen. Die Notrufnummer in den USA lautet 911. Wählen Sie im Notfall die für Ihr Land vorgesehene Notrufnummer.

Avvertenza

Il servizio Voice over IP (VoIP) e il servizio per le chiamate di emergenza non funzionano in caso di interruzione dell'alimentazione. Ristabilita l'alimentazione, potrebbe essere necessario reimpostare o riconfigurare l'attrezzatura per ottenere nuovamente l'accesso al servizio VoIP e al servizio per le chiamate di emergenza. Negli Stati Uniti, il numero di emergenza è 911. Si consiglia di individuare il numero di emergenza del proprio Paese.

Advarsel

Tjenesten Voice over IP (VoIP) og nødanropstjenesten fungerer ikke ved strømbrudd. Etter at strømmen har kommet tilbake, må du kanskje nullstille eller konfigurere utstyret på nytt for å få tilgang til VoIP og nødanropstjenesten. I USA er dette nødnummeret 911. Du må vite hva nødnummeret er i ditt land.

Aviso

O serviço Voice over IP (VoIP) e o serviço de chamadas de emergência não funcionam se houver um corte de energia. Depois do fornecimento de energia ser restabelecido, poderá ser necessário reiniciar ou reconfigurar o equipamento para voltar a utilizar os serviços VoIP ou chamadas de emergência. Nos EUA, o número de emergência é o 911. É importante que saiba qual o número de emergência no seu país.

¡Advertencia!

El servicio de voz sobre IP (VoIP) y el de llamadas de emergencia no funcionan si se interrumpe el suministro de energía. Tras recuperar el suministro es posible que deba que restablecer o volver a configurar el equipo para tener acceso a los servicios de VoIP y de llamadas de emergencia. En Estados Unidos el número de emergencia es el 911. Asegúrese de obtener el número de emergencia en su país.

Varning!

Tjänsten Voice over IP (VoIP) och larmnummertjänsten fungerar inte vid strömavbrott. Efter att strömmen kommit tillbaka måste du kanske återställa eller konfigurera om utrustningen för att få tillgång till VoIP och larmnummertjänsten. I USA är det här larmnumret 911. Du bör ta reda på det larmnummer som gäller i ditt land.

 

 



Update to the Hardware Installation Guide

The "Connectors and Cables" appendix incorrectly refers to a crossover cable as a rollover cable. This is the correct information:

You can identify a crossover cable by comparing the two modular cable ends. Hold the cable ends side-by-side, with the tab at the back, right plug, as shown in Figure 1.

Figure 1 Identifying a Crossover Cable

1

Pin 1

2

Pin 9


On a crossover cable, the wire connected to the pin on the outside of the left plug should be the same color as the wire connected to the pin on the outside of the right plug.

Update to the Getting Start Guide

When you launch Express Setup, you are prompted for the switch password. Enter the default password, cisco. The switch ignores text in the username field. Before you complete and exit Express Setup, you must change the password from the default password, cisco.

Update to the System Message Guide

These are the documentation updates for the system message guide:

New System Messages

Changed System Messages

Deleted System Messages

New System Messages

These system messages have been added:

Error Message    DOT1X_SWITCH-5-ERR_ADDING_ADDRESS: Unable to add address [enet] on 
[chars]

Explanation    The client MAC address could not be added to the MAC address table because the hardware memory is full or the address is a secure address on another port. [enet] is the supplicant MAC address, and [chars] is the interface. This message might appear if the IEEE 802.1x feature is enabled.

Recommended Action    If the hardware memory is full, remove some of the dynamic MAC addresses. If the client address is on another port, manually remove it from that port.

Error Message    %PAGP_DUAL_ACTIVE-3-OBJECT_CREATE_FAILED: Unable to create [chars] 

Explanation    The switch cannot create the specified managed object. [chars] is the object name.

Recommended Action    No action is required.

Error Message    %PAGP_DUAL_ACTIVE-3-RECOVERY_TRIGGER: PAgP running on [chars] 
informing virtual switches of dual-active: new active id [enet], old id [enet] 

Explanation    Port Aggregation Protocol (PAgP) received a new active ID on the specified interface, which means that all virtual switches are in a dual-active scenario. The interface is informing virtual switches of this, which causes one switch to go into recovery mode. [chars] is the interface. The first [enet] is the new active ID. The second [enet] is the ID that it replaces.

Recommended Action    No action is required.

Error Message    %PAGP_DUAL_ACTIVE-3-REGISTRY_ADD_ERR: Failure in adding to [chars] 
registry 

Explanation    The switch could not add a function to the registry. [chars] is the registry name.

Recommended Action    No action is required.

Error Message    %PM-6-EXT_VLAN_ADDITION: Extended VLAN is not allowed to be configured 
in VTP CLIENT mode. 

Explanation    The switch did not add a VLAN in VTP client mode.

Recommended Action    Copy the message exactly as it appears on the console or in the system log. Research and attempt to resolve the error by using the Output Interpreter. Use the Bug Toolkit to look for similar reported problems. If you still require assistance, open a case with the TAC, or contact your Cisco technical support representative, and provide the representative with the gathered information. For more information about these online tools and about contacting Cisco, see the "Error Message Traceback Reports" section in the system message guides.

Error Message    SPANTREE-6-PORTADD_ALL_VLANS: [chars] added to all Vlans 

Explanation    The interface has been added to all VLANs. [chars] is the added interface.

Recommended Action    No action is required.

Error Message    SPANTREE-6-PORTDEL_ALL_VLANS: [chars] deleted from all Vlans 

Explanation    The interface has been deleted from all VLANs. [chars] is the deleted interface.

Recommended Action    No action is required.

Error Message    SW_VLAN-6-VTP_DOMAIN_NAME_CHG: VTP domain name changed to [chars]. 

Explanation    The VLAN Trunking Protocol (VTP) domain name was changed through the configuration to the name specified in the message. [chars] is the changed domain name.

Recommended Action    No action is required.

Error Message    VQPCLIENT-2-TOOMANY: Interface [chars] shutdown by active host limit. 

Explanation    The system has shut down the specified interface because too many hosts have requested access to that interface. [chars] is the interface name.

Recommended Action    To enable the interface, remove the excess hosts, and enter the no shutdown interface configuration command.

Error Message    VQPCLIENT-3-VLANNAME: Invalid VLAN [chars] in response. 

Explanation    The VLAN membership policy server (VMPS) has specified a VLAN name that is unknown to the switch. [chars] is the VLAN name.

Recommended Action    Ensure that the VLAN exists on the switch. Verify the VMPS configuration by entering the show vmps privileged EXEC command.

Error Message    WCCP-5-CACHEFOUND: Web Cache [IP_address] acquired. 

Explanation    The switch has acquired the specified web cache. [IP_address] is the web cache IP address.

Recommended Action    No action is required.

Error Message    WCCP-1-CACHELOST: Web Cache [IP_address] lost. 

Explanation    The switch has lost contact with the specified web cache. [IP_address] is the web cache IP address.

Recommended Action    Verify the operation of the web cache by entering the show ip wccp web-cache privileged EXEC command.

Changed System Messages

This system message has changed (both explanation and action).

Error Message    EC-5-CANNOT_BUNDLE1: Port-channel [chars] is down, port [chars] will 
remain stand-alone. 

Explanation    The aggregation port is down. The port remains standalone until the aggregation port is up. The first [chars] is the EtherChannel. The second [chars] is the port number.

Recommended Action    Ensure that the other ports in the bundle have the same configuration.

Error Message    ILPOWER-3-CONTROLLER_PORT_ERR:Controller port error, Interface 
Fa0/7:Power given, but link is not up.

Explanation    The inline-power-controller reported an error on an interface.

Recommended Action    Enter the shutdown and no shutdown interface configuration commands on the affected interfaces. Upgrade to Cisco IOS Release12.1(14)EA1 or later, which provides an electrostatic discharge (ESD) recovery mechanism.

Deleted System Messages

These system messages were deleted:

Error Message    %VQPCLIENT-2-INITFAIL: Platform-specific VQP initialization failed. 
Quitting 
Error Message    %VQPCLIENT-2-IPSOCK: Could not obtain IP socket 
Error Message    %VQPCLIENT-7-NEXTSERV: Trying next VMPS [IP_address] 
Error Message    %VQPCLIENT-7-PROBE: Probing primary server [IP_address] 
Error Message    %VQPCLIENT-2-PROCFAIL: Could not create process for VQP. Quitting 
Error Message    %VQPCLIENT-7-RECONF: Reconfirming VMPS responses 
Error Message    %VQPCLIENT-2-SHUTDOWN: Interface [chars] shutdown by VMPS 
Error Message    %VQPCLIENT-3-THROTTLE: Throttling VLAN change on [chars] 

Related Documentation

These documents provide complete information about the switch and are available from this Cisco.com site:

http://www.cisco.com/en/US/products/hw/switches/ps646/tsd_products_support_series_home.html

Catalyst 3550 Multilayer Switch Software Configuration Guide

Catalyst 3550 Multilayer Switch Command Reference

Catalyst 3750, 3560, 3550, 2970, and 2960 Switch System Message Guide

Catalyst 3550 Multilayer Switch Hardware Installation Guide

Catalyst 3550 Switch Getting Started Guide

Regulatory Compliance and Safety Information for the Catalyst 3550 Switch

For information about other related products, see these documents:

Getting Started with Cisco Network Assistant

Release Notes for Cisco Network Assistant

Network Admission Control Software Configuration Guide

Information about Cisco SFP, SFP+, and GBIC modules is available from this Cisco.com site:

http://www.cisco.com/en/US/products/hw/modules/ps5455/prod_installation_guides_list.html

SFP compatibility matrix documents are available from this Cisco.com site:

http://www.cisco.com/en/US/products/hw/modules/ps5455/products_device_support_tables_list
.html

Obtaining Documentation, Obtaining Support, and Security Guidelines

For information on obtaining documentation, obtaining support, providing documentation feedback, security guidelines, and also recommended aliases and general Cisco documents, see the monthly What's New in Cisco Product Documentation, which also lists all new and revised Cisco technical documentation, at:

http://www.cisco.com/en/US/docs/general/whatsnew/whatsnew.html