Single host using software iSCSI reports datastore redundancy lost against all datastores

Products

• VMware vSphere ESXi
• VMware vSphere ESX 8.x
• VMware vSphere ESX 7.x

Issue/Introduction

Single host using software iSCSI reports datastore redundancy lost.

Datastore redundancy is lost to all datastores presented to the ESXi host.

Environment

VMware vSphere ESXi 7.0
VMware vSphere ESXi 8.0

Cause

Another device on the network has taken the IP address of the vmkernel ports that are responsible for iSCSI traffic.

ESXi: /var/log/vmkernel.log
####-##-##T##:##:##.###Z cpu7:2098544)Tcpip_Vmk: 124: arp: ##:##:##:##:##:## is using my IP address <IP of iSCSI kernel port> on vmk2!
####-##-##T##:##:##.###Z cpu25:2098549)Tcpip_Vmk: 124: arp: ##:##:##:##:##:## is using my IP address  <IP of iSCSI kernel port> on vmk3!
.
.
####-##-##T##:##:##.###Z cpu3:2098597)WARNING: iscsi_vmk: iscsivmk_StopConnection:738: vmhba64:CH:# T:# CN:0: iSCSI connection is being marked "OFFLINE" (Event:4)

Resolution

Please contact you networking team and investigate the mac address that has taken the IP address of the iSCSI kernel ports.