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="3e08cb4e-f38c-4d01-a8cc-f0987650e6e8" 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 3e08cb4e-f38c-4d01-a8cc-f0987650e6e8.
 
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.