Cisco 2600 Series Multiservice Platforms

Field Notice: Cisco 2620 and 2621 Clock and Timing Problems

April 15, 1999

Products Affected








Problem Description

Cisco 2620 and 2621 units may have part of the system information programmed incorrectly. This information tells the Cisco IOS software the frequency of the clock on the main board. Cisco IOS software uses this to set up counters that drive all time based functions in the Cisco 2620 and 2621.


This problem affects Cisco 2620 and Cisco 2621 units manufactured prior to March 19, 1999. This problem does not affect the Cisco 2610, Cisco 2611, Cisco 2612 or Cisco 2613.

Problem Symptoms

The symptoms of this problem fall into these categories:

  1. Timing related functions. All software operations that rely on timing will be 25% fast. This includes time of day, routing tables updates, etc.

  2. Clocking on the WAN Interface Card (WIC) interfaces. Serial interfaces configured for synchronous DCE mode will drive the clock 25% too fast (DTE mode is not affected). WIC async ports will use a baud rate 25% too fast (console, aux, and network module ports are not affected). Async applications will fail when using the WIC port.

  3. Performance of the Network Timing Protocol (NTP) will be affected by this problem. The discrepency in the system clock will cause the NTP process to fail to sync up.


Install a Cisco IOS software release with the fix for DDTS CSCdm14836 (registered customers only) . This includes Cisco IOS releases 12.0(3)T2, 12.0(3)T3 and 12.0(4)T and later.





Cisco 2620 and 2621 Clock Timing Enhancements


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



CSCdm14836 (registered customers only)

Quake FE Cookie Speed Bit Incorrectly Programmed

Cisco IOS Versions Affected

This problem affects Cisco IOS software versions 12.0(2)XC and 12.0(3)T.

How To Identify Hardware Levels

You can tell which units are affected by the main board version.


Affected Main Board Versions

Main Board Versions Not Affected


73-2843-01 73-2843-02 73-2843-03

73-2843-04 and later


73-3200-01 73-3200-02 73-3200-03

73-3200-04 and later

You can identify the version of the main board with the Cisco IOS show diag command:

Router>show diag
Slot 0:
        C2620 1FE Mainboard port adapter, 2 ports
        Port adapter is analyzed
        Port adapter insertion time unknown
        EEPROM contents at hardware discovery:
        Hardware revision  1.0          Board revision A0
        Serial number      696473549    Part number  73-2843-04
        Test history       0x0          RMA number   00-00-00
        EEPROM format version 1
        EEPROM contents (hex):
          0x20: 01 94 01 00 29 83 57 CD 49 0B 1B 02 00 00 00 00
          0x30: 50 00 00 06 00 00 00 00 00 00 00 00 00 00 00 00

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: