vSphere Replication fails with "Network is unreachable" error due to incorrect IP advertisement

Products

• VMware vSphere ESXi

Issue/Introduction

Symptoms:

• Virtual machine replication status shows as Not Active or RPO Violation.
• Attempts to sync or configure replication fail with the error: A replication error occurred at the vSphere Replication Server... Error: Network is unreachable.
• Source ESXi host hbr-agent logs show communication attempts toward the Management IP of the target VR appliance instead of the dedicated Replication IP: 

2026-06-09T05:23:14.180Z In(166) hbr-agent-bin[134636378]: [0x000000ade17b2700] info: [Proxy [Group: ] -> [172.##.###.##:32032]] Bound to vmk: vmk2 for connection to 172.##.###.##:32032
2026-06-09T05:23:14.180Z In(166) hbr-agent-bin[134636378]: [0x000000ade17b2700] error: [Proxy [Group: ] -> [172.##.###.##:32032]] Failed to connect to 172.##.###.##:32032. Using nic 'vmk2'. Error: Network is unreachable

 

Environment

• VMware Live Recovery 9.x
• vSphere Replication 9.x

Cause

The issue occurs when the target vSphere Replication appliance incorrectly advertises its Management interface (eth0) for incoming replication traffic instead of the dedicated Replication interface (eth1). This is typically caused by:

1. The replication IP not being correctly registered in the appliance configuration file (hbrsrv-nic.xml).
2. An incorrect or missing gateway configuration for the dedicated replication NIC (eth1) on the VR appliance.

Resolution

To resolve this issue, manually update the appliance configuration and verify network routing.

Step 1: Update hbrsrv-nic.xml on the Target Appliance

1. Log in to the target vSphere Replication appliance via SSH as root.
2. Backup the existing configuration file: cp /opt/vmware/etc/hbr/hbrsrv-nic.xml /opt/vmware/etc/hbr/hbrsrv-nic.xml.bak
3. Edit the file using a text editor (e.g., vi): vi /opt/vmware/etc/hbr/hbrsrv-nic.xml
4. Ensure the <address> tag contains the dedicated Replication IP address of the appliance:
   <config><ipForHMS /><ipForFilter>10.20.#.#</ipForFilter><ipForNFC /></config>
5. Save and close the file.

Step 2: Correct the Replication Interface Gateway

1. Access the vSphere Replication Appliance Management Interface (VAMI) via https://VR_Appliance_IP:5480.
2. Navigate to Network > Address.
3. Verify that the dedicated replication interface (typically eth1) has the correct Gateway address for its subnet.
4. Update the gateway if necessary and save the settings.

Step 3: Restart vSphere Replication Services

1. From the SSH session on the VR appliance, restart the replication service to apply the changes: 
   • systemctl restart hbrsrv
   • systemctl restart hms

Step 4: Verify Connectivity

1. Log in to the source ESXi host via SSH.
2. Test connectivity from the dedicated replication VMkernel to the target VLR Replication IP: vmkping -I vmk# Target_Replication_IP