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Cisco 7600 Series Routers

FN - 62346 - 7600-SIP-400 May Drop Bursty Egress Traffic - Upgrade FPD Image


Revised May 15, 2006

April 20, 2006

NOTICE:

THIS FIELD NOTICE IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTY OF MERCHANTABILITY. YOUR USE OF THE INFORMATION ON THE FIELD NOTICE OR MATERIALS LINKED FROM THE FIELD NOTICE IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS FIELD NOTICE AT ANY TIME.


Products Affected

Product

Top Assembly Part #

Printed Circuit Assembly Part #

Comments

7600-SIP-400 (=)

68-1920-14

73-8890-08

73-8404-13

CLEI Code: IPUIAPBRAA is affected. Bonham Switch FPGA version below 0.29 is affected

Problem Description

7600-SIP-400 may exhibit packet loss on the egress interfaces. Cisco has diagnosed that this is more prevalent with bursty traffic patterns. Packet loss on the egress interfaces may result in loss of routing protocol neighbor adjacency, routes and so on. Cisco has released an FPGA upgrade to resolve the halt in packet forwarding on the 7600-SIP-400 linecard. The FPGA fix was first made available in FPD images for 12.2(18)SXF3 and 12.2(18)SXE5. All product shipped from Cisco Manufacturing contains the updated FPD image.

Note: For those customers that use Common Language Equipment Identifier (CLEI) codes for traceability, the CLEI code has changed from IPUIAPBRAA to IPUIAZ6RAA.

Cisco recommends that all 7600-SIP-400 linecards should be upgraded to the latest FPD image, even if they are not currently seeing the problem.

Cisco Best Practice is to load the FPD Image Package corresponding to the IOS version running on the system. In specific situations such as a Field Notice, customers can use the Manual Upgrade SIP FPD Image Procedure to avoid this contingency.

Use the following block diagram to determine what action is required.

fn62346_iwlpu1.gif

Background

Engineering analyzed failing 7600-SIP-400 linecards and discovered a problem which was traffic pattern dependant. The failure involved a device on the linecard getting into a locked state such that packet forwarding halted and packets where being dropped. The locked state has only been observed on traffic internally designated as "low priority" while "higher priority" traffic continued to flow.

This problem is also being tracked under the DDTS CSCsc68250. This can be viewed using the Cisco Bug Toolkit.

Problem Symptoms

Customers may experience packet loss. To attribute the packet loss specifically to this problem the Bonham FPGA counters need to be monitored.

Cisco has seen the locked state occur when the Low Priority (LP) buffer drops [Pkt buf LP pkt drops] are incrementing and the Low Priority (LP) Buffer Packets [PKT BUF LP Packets] are not incrementing.

Use the following procedure to check the Bonham FPGA counters.

Connect to the 7600-SIP-400= using the command attach [slot#]

CISCO7609#attach 5

Entering CONSOLE for slot 5

Type "^C^C^C" to end this session 
SIP-400-5> 
SIP-400-5> enable 
SIP-400-5#

Once logged into the 7600-SIP-400, check the Bonham FPGA counters using the command show platform hardware bonham counters | inc Pkt buf|PKT BUF.

SIP-400-5#show platform hardware bonham counters | inc Pkt buf|PKT BUF

PKT BUF HP Packets (offset 0x050C)   137809 

PKT BUF LP Packets (offset 0x0510) 4691549512

Pkt buf HP pkt drops (offset 0x0534) 0 

Pkt buf LP pkt drops (offset 0x0538) 576528 

  SIP-400-5#

Cisco engineers have only seen the Low Priority Packets exhibit this problem. However, it is possible that the High Priority (HP) buffers may exhibit these symptoms therefore both sets of counters should be observed for a couple of cycles.

Workaround/Solution

Workaround:

Reload the module.

Solution:

The new version of FPGA for the Bonham Switch FPGA is version 0.29 and was first made available in the following FPD images:

  • c7600-fpd-pkg.122-18.SXF3.pkg

  • c7600-fpd-pkg.122-18.SXE5.pkg

Note: If you are running an SXE IOS image, you should use the SXE5 FPD package (c7600-fpd-pkg.122-18.SXE5.pkg). If you are running an SXF IOS image you should use the SXF3 FPD package (c7600-fpd-pkg.122-18.SXF3.pkg).

To obtain this software please go to the Cisco Software Center and follow the IOS Upgrade Planner to select your platform and associated FPD Image from either 12.2.18-SXF3 or 12.2.18-SXE5.

FPD Image Packages can be upgraded automatically or manually. The FPD automatic upgrade feature only searches for the FPD Image Package file that is the same version as the Cisco IOS release being used by the system. For example, if the system is running Cisco IOS Release 12.2(18)SXE5, then the system will search for the FPD image package file (c7600-fpd-pkg-122-18SXE5.pkg). Cisco recommends that in specific situations such as a Field Notice, customers can use the Manual Upgrade SIP FPD Image Procedure to get around this contigency on the Cisco IOS version matching.

Note: All new product being shipped, contains the upgraded FPD image.

To upgrade the 7600-SIP-400, you will need to run the following CLI command:

'upgrade hw-module slot <slot> file <filespec>'

where: slot = slot containing SIP400 card filespec = URL of FPD package file. It can be on disk0:,ftp, tftp and so on.

For example, if it is on disk0:

upgrade hw-module slot 5 file disk0:c7600-fpd-pkg.122-18.SXF3.pkg

Specific examples of using this command are available in the Cisco 7600 Series Router SIP, SSC, and SPA Software Configuration Guide .

It should only take a few minutes to ugprade the FPGA and the 7600-SIP-400 will automatically get rebooted with the new Bonham Switch FPGA image.

You can use the following CLI command the verify that the Bonham Swtich FPGA version has upgraded:

show hw-module slot fpd

After the upgrade, it should look like this (without SPA's installed):

fn62346_iwnun2.jpg

Note: No IOS changes are required to use the new FPGA version.

If you would like some further information on ugprading FPD images, please refer to the Upgrading Field-Programmable Devices section in the Cisco 7600 Series Router SIP, SSC, and SPA Software Configuration Guide .

DDTS

To follow the bug ID link below and see detailed bug information, you must be a registered user and you must be logged in.

DDTS

Description

CSCsc68250 (registered customers only)

Packet flow halt on 7600-SIP-400

How To Identify Hardware Levels

Check the Bonham FPGA version using the CLI command show hw-module slot <slot> fpd

fn62346_iwnfuk.jpg

Note: The Field Programmable Device ID-Name '3-SWITCH FPGA' must be lower then 0.29 to be affected by this problem.

Check the CLEI code using the command show idprom module <module#> clei.

fn62346_ixw66i.jpg

Revision History

Revision

Date

Comment

1.1

15-MAY-2006

Updated Problem Description, Problem Symptom and Workaround/Solution sections

1.0

20-APR-2006

Initial Public Release

For More Information

If you require further assistance, or if you have any further questions regarding this field notice, please contact the Cisco Systems Technical Assistance Center (TAC) by one of the following methods:

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