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Cisco Bug: CSCul15867 - Diagnostic Test fails on admin-down port

Last Modified

Dec 29, 2020

Products (3)

  • CiscoPro Workgroup EtherSwitch Software
  • Cisco Nexus 7000 10-Slot Switch
  • Cisco Nexus 7000 18-Slot Switch

Known Affected Releases


Description (partial)

Log messages about Port Loopback Test Fails 

DIAG_PORT_LB-2-PORTLOOPBACK_TEST_FAIL  Module:1 Test:PortLoopback failed 10 consecutive times. Faulty module:Module 1 affected ports:22  Error:Loopback test failed. Packets lost on the LC at the MAC ASIC

MODULE-4-MOD_WARNING  Module 1 reported warning on ports 1/22-1/22 (Ethernet) due to Loopback test failed. Packets lost on the LC at the MAC ASIC in device 96 (device error 0x41830059)


* port is admin-down
* issue happened after ISSU to 5.1(4) or similar train code
* re-running diagnostic moves failure to new port
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