PowerEdge: Mellanox ConnectX-4 LX reports Length Errors
Summary: Mellanox ConnectX-4 LX reports Length Errors when Network MTU is not configured at the same END-TO-END.
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This article is not tied to any specific product.
Not all product versions are identified in this article.
Symptoms
When jumbo size frames are received on an interface, where jumbo size frames are not enabled and the card statistics were logging Receive Length Error.
Cause
Using iSCSI with the source MTU size of 1500 (default), but the switch was set to Jumbo frames and was getting Receive Length Errors in the card's statics.
Resolution
Setting the MTU to be equal throughout the network data path is a general network design best practice to avoid to receiving packets larger than the port is configured to handle.
Do not replace any hardware.
This is working as designed.
Affected Products
OEMR R440, OEMR R540, OEMR R640, OEMR R6415, OEMR R740, OEMR R740xd, OEMR R740xd2, OEMR R7415, OEMR R7425, OEMR R840, OEMR R940, OEMR R940xa, OEMR T640, Poweredge C4140, PowerEdge C6420, PowerEdge FC640, PowerEdge R440, PowerEdge R540, PowerEdge R640
, PowerEdge R6415, PowerEdge R740, PowerEdge R740XD, PowerEdge R740XD2, PowerEdge R7415, PowerEdge R7425, PowerEdge R840, PowerEdge R940, PowerEdge R940xa, PowerEdge T640
...
Article Properties
Article Number: 000147729
Article Type: Solution
Last Modified: 13 Oct 2025
Version: 4
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