Unable to replicate VM error " No connection to VR Server"

Products

• VMware Live Recovery

Issue/Introduction

Symptoms

• Virtual machine with replication configured shows the below alert in vCenter server:

• When trying to configure replication for a VM using vSphere replication following error is encountered 

Error : A replication error occurred at the vSphere Replication Server for replication "VM name: test". Details: 'No connection to VR Server for virtual machine "VM name: test" on host "ESXi host : host1" in cluster "Cluster name : cluster1" in "Cluster name : cluster1" : Unknown'.

• Virtual Machines may be showing as "Not Active (RPO Violation)" on some ESXI hosts but works when migrated to other ESXi hosts

/var/run/log/vmkernel.log indicates

 vmkwarning: cpu69:2137316) WARNING: Hbr: 383: Failed to connect to TARGET_VR_IP (groupID=GID-XXXXXX-XXXX-XXXX-XXXX-XXXXXXXX): Network unreachable
 vmkwarning: cpu55:2135354) WARNING: Hbr: 5362: Failed to establish connection to [TARGET_VR_IP]:31031 (groupID=GID-XXXXXX-XXXX-XXXX-XXXX-XXXXXXXX): Network unreachable 

Environment

VMware Live Recovery 9.X

Cause

This issue occurs when the target vSphere Replication appliance is unable to establish communication with the source ESXi host’s VMkernel interface carrying replication traffic, typically due to a missing static route, particularly when the source host resides on a different subnet.

Resolution

A static route was added on the affected ESXi hosts to ensure proper routing to the target broker.

list existing routes on the ESXi host

#esxcli network ip route ipv4 list

To add a static route:

#esxcli network ip route ipv4 add --gateway <IPv4_gateway_address> --network <destination_network>/<subnet>

esxcli network ip route ipv4 add --gateway xx.xx.xx.xx --network ##.##.##.##/24

Additional Information

Configuring static routes for vmkernel ports on an ESXi host refer https://knowledge.broadcom.com/external/article/308786/configuring-static-routes-for-vmkernel-p.html