Alert "fp-ethX receive ring buffer has overflowed" may be received for [fp-ethX] interface not configured for data path processing.

Products

• VMware NSX

Issue/Introduction

Symptoms:

You may see alerts "Edge NIC Out Of Received Buffer " showing for [fp-thx] which is not configured for data path.







From ADF collection covering the alert  we can reference an odd behavior of receiving but nothing getting sent.

We also see the following 2 error metrics :


While on TX all values are 0



fp-ethX Interface has only rx and no tx and is not actively participating in datapath processing.

So why would that interface[fp-eth2] be subject to the following alert ?
 
/var/log/syslog

2020-12-02T16:09:36.471Z xxxxxx.xxx.xxx NSX 8976 - [nsx@6876 comp="nsx-edge s2comp="nsx-monitoring" entId="xxxxxxx-xxxx-xxxx-xxxx-xxxxxxxx" tid="9090" level="FATAL" eventState="On" eventFeatureName="edge_health" eventSev="critical" eventType="edge_nic_out_of_receive_buffer"] Edge NIC fp-eth2 receive ring buffer has overflowed by 11.873445% on Edge node xxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxxxx.
 
Note: This log excerpt is an example. Date, time, and environmental variables may vary depending on your environment.

 

Environment

VMware NSX-T Data Center

Cause

This is caused by a known defect; the previous code was just taking the count to index the port, but internally the port id may be different.

This works fine for port 0 but for other ports, there may be inconsistency.

Resolution

This known issue is fixed in 3.0.2, 3.1, 3.1.1, 3.1.2, and 3.2

Workaround:
If your fp-ethX interface has only rx and no tx and is not actively participating in datapath processing; then it is safe to ignore the alert.

Additional Information

For information related to ADF data collection mentioned in this knowledge base article, please refer, Troubleshooting NSX Edge and Virtual Machine (VM) Performance