Binding a vmk interface to iPerf3 fails with the error message: “iperf3: error – unable to start listener for connections: Cannot assign requested address.”

Products

• VMware vSphere ESXi
• VMware vSphere ESXi 8.0

Issue/Introduction

• When attempting to bind a vmk adapter as the iPerf3 server or client following the steps in Broadcom KB 312678, the operation fails with the error:
  “iperf3: error – unable to start listener for connections: Cannot assign requested address.”
  
  

• [root@###-##:/usr/lib/vmware/vsan/bin/iperf3 -V --server --bind <IP Address Of VMK> -fM
  iperf 3.10.1
  VMkernel ###-##.####.##### 8.0.2 #1 SMP Release build-######## MM  DD YYYY 15:00:49 x86_64
  iperf3: error - unable to start listener for connections: Cannot assign requested address
  iperf3: exiting

Environment

VMware vSphere ESXi

Cause

iPerf3 supports binding only to interfaces associated with the default TCP/IP stack (default NetStack). Other NetStack like vMotion is not supported. 

Resolution

Ensure that both the source and destination network interfaces are configured within the default TCP/IP stack.

Additional Information

You can identify the NetStack type of a VMkernel adapter by running: 

esxcfg-vmknic -l




Alternatively, this information can also be viewed through the vCenter/host UI.