Loss of redundant connectivity to Storage, path Status reflects as "Not Used"

Products

• VMware vSphere ESXi

Issue/Introduction

Symptoms:

• One of the vmkernel reports path status as "Not used" under "Network Port Binding "
  
  
  
  
  
• vobd.log reports connection failure
  2025-06-25T14:22:50.538Z In(14) vobd[2097956]:  [iscsiCorrelator] 2712397091694us: [vob.iscsi.discovery.connect.error] discovery failure on vmhba64 to 192.168.0.#3 because of a network connection failure.
  2025-06-25T14:22:50.538Z In(14) vobd[2097956]:  [iscsiCorrelator] 2712464898112us: [esx.problem.storage.iscsi.discovery.connect.error] iSCSI discovery to 192.168.0.#3 on vmhba64 failed. The iSCSI Initiator could not establish a network connection to the discovery address.
  
  
  
• vmkping -I vmk3 -d -s 8972 192.168.0.#3
  PING 192.168.0.141 (192.168.0.#3): 8972 data bytes
  sendto() failed (Host is down)
  
  

Environment

VMware vSphere ESXi 

Cause

• use following cmd to check the configured IP's for the vmkernel.

esxcfg-vmknic -l
Interface  Port Group/DVPort/Opaque Network   IP Family IP Address      Netmask         Broadcast       MAC Address       MTU     TSO MSS   Enabled Type    NetStack
vmk0       2231                               IPv4      ##.##.##.##     255.255.##.0      10.##.##.##   ##:##:##:##:##:## 1500    65535     true    STATIC  defaultTcpipStack
vmk1       29                                 IPv4      192.168.0.#1    255.255.255.0   192.168.0.255   ##:##:##:##:##:## 9000    65535     true    STATIC  defaultTcpipStack
vmk2       36                                 IPv4      192.168.0.#2    255.255.255.0   192.168.0.255   ##:##:##:##:##:## 9000    65535     true    STATIC  defaultTcpipStack
vmk3       116                                IPv4      192.168.0.#3    255.255.255.0   192.168.0.255   ##:##:##:##:##:## 9000    65535     true    STATIC  defaultTcpipStack
vmk4       124                                IPv4      192.168.0.#4    255.255.255.0   192.168.0.255   ##:##:##:##:##:## 9000    65535     true    STATIC  defaultTcpipStac4

We can see that vmk1, vmk2, vmk3 and vmk4 all are on same TCP/IP stack.

• Configurations with more than one vmknic in the same IP subnet and TCP/IP stack is not supported.

Resolution

Ensure the VMkernel ports are in a different IP subnets or have their own TCP/IP stack as Multihoming is not supported on ESXi

Reference KB : Multihoming on ESXi
Multihoming in a VMkernel networking context means that there are multiple VMkernel adapters (vmknic) in a single TCP/IP stack (Netstacks).