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Cisco Bug: CSCuq96419 - WH2: Address MCB timeout issue on VSC8574x

Last Modified

Sep 14, 2019

Products (16)

  • Cisco ME 3600X Series Ethernet Access Switches
  • Cisco ASR 901-6CZ-F-D Router
  • Cisco ME 3600X-24TS-M Switch
  • Cisco ASR 901-4C-FT-D Router
  • Cisco ASR 901S-4SG-F-D Router
  • Cisco ASR 901S-2SG-F-D Router
  • Cisco ASR 901-6CZ-F-A Router
  • Cisco ASR 901-6CZ-FT-A Router
  • Cisco ASR 901-12C-FT-D Router
  • Cisco ASR 901S-3SG-F-D Router
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Known Affected Releases


Description (partial)

The following log is observed after the system bootup (and continues to be observed later as well):

000268: Aug 29 08:46:00.269 brz-3: SPI pause fail!, port 340020368
000269: Aug 29 08:46:00.269 brz-3: MCB timeout, port_no 340020264

When this issue occurs, some 1G port in the system (due to another bug in the software, the port number is not displayed correctly in above log message), has an issue in dealing with PTP packets. The timestamp module on those ports in the PHY does not work correctly and the recovered clock accuracy could go bad. No other traffic is impacted when this symptom is seen.

The problem could occur when the switches have Rev.D PHY chips with a very thin frequency (of about 2-3 times a year with multiple reboots). From the observations of this issue, the occurrence has been linked to the bootup of the box with the PTP configuration.
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