Excessive CRC alignment errors on UEM or switch log


Symptom(s)

Multiple ports in switches and other devices (i.e. CAM) reporting CRC errors. 

Issue

Excessive CRC alignment error on UEM or switch logs typically mean one of two things; speed/duplex mismatch between device and switch port or cabling issue.
 
 

 

Environment

 

 

Resolution

Based on the ports/consoles/devices experiencing CRC error issues:

1. Check speed/duplex configuration matches between device and switch port.

2. Check cables. 

For Windows based devices check NIC settings if Legacy Switch Compatibility Mode is applicable.

Enabling Legacy Switch Compatibility Mode
1 From Search, open Control Panel.
2 In the Control Panel window, click Network and Internet→Network and Sharing Center.
3 In the Network and Sharing Center window, from the menu on the left, click Change adapter
settings.
4 Right-click your active local area connection and select Properties.
5 If the User Account Control (UAC) window appears, click Yes.
6 In the local area connection properties window, select Configure.
7 On the Advanced tab, from the Property list, set the Legacy Switch Compatibility Mode
value to Enabled, and click OK.

8 Check if speed is set to 100 full duplex