vSphere Replication Cannot establish a TCP connection to server at 'X.X.X.X:8123' Details 'https://X.X.X.X:8123/invocation failed with "java.net.NoRouteToHostException: No route to host (Host unreachable)"'.

Products

• VMware Live Recovery

Issue/Introduction

The vSphere Replication appliance was not able to register with the replication server. Traffic from the appliance to the server’s IP address was not reachable.

Environment

VMware vSphere Replication 8.x

Cause

The vSphere Replication appliance had multiple default routes with different metrics.

ip route show default
default via X.X.X.X dev eth1 proto static
default via X.X.X.X dev eth0 proto static metric 1000

Linux routing chooses the default route with the lowest metric for traffic that does not match a more specific route. Since the default route via eth1 had the lower metric, traffic to the specific destination was incorrectly sent through eth1 instead of eth0.

Resolution

Add a specific route for the destination via the correct interface, see:

Configure a Static Route on an Additional VM Network Adapter.

Additional Information

• For temporary testing, ping -I <interface> can force traffic out a specific interface.
• Use ip route get <destination ip> to verify which interface will be used for traffic.