Cisco Catalyst 6000 Series Switches

WS-X6516-GBIC Compatibility Issue With the Policy Feature Card 3 (PFC3) and Distributed Forwarding Card 3 (DFC3)

Revised January 20, 2005

July 22, 2003

Products Affected


Top Assembly

Printed Circuit Assembly

HW Rev.

Part Number


Part Number



68-1440-02 through 68-1440-03


73-7300-02 through 73-7300-04


5.0 through 5.4

Problem Description

Certain hardware versions of WS-X6516-GBIC do not contain data bus (DBUS) flow control resistors. The hardware versions affected are 5.0 to 5.4. In Sup720 Policy Feature Card 3 (PFC3) based systems, these cards will only work in flow-through mode.


The WS-X651G-GBIC hardware versions 5.0-5.4 are the only boards that do not have the DBUS flow control resistors installed on the board. When used in a Sup720 PFC3 system, this results in a sequence error if the card is in Truncated or Compact Mode. When used in Truncated and Compact Mode, these hardware versions cannot use hardware acceleration of protocols. GRE, NAT, IP in IP and WCCP are a few examples. When used in flow-through mode, they operate normally. To save performance degradation on the entire system, the software on Sup720 will automatically place a board that falls within this hardware version to perform in flow-through mode. If an affected board has a Distributed Forwarding Card 3 (DFC3) on it, the board will be powered down.

Older versions of the WS-X6516-GBIC with hardware versions earlier than 5.0 include the resistor required for flow control. These boards are not impacted in Sup720 PFC3 systems and will operate normally. A change was made to add the resistors on new builds. Any board with hardware version 5.5 and later will have this fixed.

One caveat to this resistor change is that any board version 5.0 or later may see a slight drop in network performance when used with Sup2 running 6.1(x). In this configuration, it was determined that impact to the performance will be negligible. After conducting experiments to test the performance impact, it was observed that the worst case packet rate reduction was from 1.358mpps to 1.147mpps. This was only observed on 6.1(1e).

Problem Symptoms

In Sup720 PFC3 based systems:

For hardware versions 5.0 thru 5.4, the software will recognize affected hardware versions and place the board in flow-through mode. If there is a DFC3 installed on it, the board will be powered down.


In Sup720 (PFC3 based) system:

Hardware versions 1.x, 2.x, 4.x and 5.5 and later will not exhibit this issue. Customers wishing to receive a board that is useable in truncated and compact mode may request a product RMA.

In Sup2 system:

Hardware versions later than 5.0 may see a slight drop in network performance when using CatOS 6.1(x). It is recommended to upgrade to software version 6.2 or later. An upgrade to 6.2 or later will resolve any performance impact on an existing Sup2 system.

How To Identify Hardware Levels

Boards with hardware version between 5.0 and 5.4 are affected. To identify the hardware version of your board, use the following commands:

For Cisco® IOS, use the show idprom mod X, where X is the slot number of the board:

Router#show idprom mod 4
IDPROM for module #4
  (FRU is 'SFM-capable 16-port GigE')
  OEM String = 'Cisco Systems'
  Product Number = 'WS-X6516-GBIC'
  Serial Number = 'SAL06489DVD'
  Manufacturing Assembly Number = '73-7300-03'
  Manufacturing Assembly Revision = 'B0'
  Hardware Revision = 5.1           <<===== Hardware Version Here
  Current supplied (+) or consumed (-) = -2.93A

For CatOS, use the show version command:

Console> (enable) show version
          WS-C6506 Software, Version NmpSW: 5.5(3)
     Copyright (c) 1995-2000 by Cisco Systems 
     NMP S/W compiled on Sep  8 2000,17:39:10

     System Bootstrap Version: 5.3(1)

     Hardware Version: 2.0  Model: WS-C6506  Serial #: TBA04321604

     Mod Port Model               Serial #    Versions
     --- ---- ------------------- ----------- --------------------------------------
     1   2    WS-X6K-SUP1A-2GE    SAD04300J7L Hw : 3.2 
                                             Fw : 5.3(1)
                                              Fw1: 5.1(1)CSX 
                                             Sw : 5.5(3) 
                                             Sw1: 5.5(3)
              WS-F6K-PFC          SAD042604HE Hw : 1.1 
    3   16   WS-X6516-GBIC  SAD04310B2K Hw : 1.2 <<===== Hardware Version Here
                                              Fw : 5.4(2)
                                              Sw : 5.5(3)
     15  1    WS-F6K-MSFC         SAD0428191K Hw  : 1.4 
                                             Fw : 12.1(2)E,
                                              Sw : 12.1(2)E,

                  DRAM                    FLASH                   NVRAM
     Module  Total   Used    Free    Total   Used    Free    Total Used  Free
     ------ ------- ------- ------- ------- ------- ------- ----- ----- ----- 
     1       65408K  39081K  26327K  16384K   6971K   9413K  512K  210K  302K
    Uptime is 3 days,23 hours, 42 minutes

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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