---
name: vpc-vpn-ts-routing-issues
title: Why are my VPN gateways or virtual server instances not communicating?
description: When a connection is created successfully, the VPN service adds a `0.0.0.0/0 via <VPN gateway private IP>` route into the default routing table of the VPC. However, this new route can cause routing issues.
last-updated: 2025-12-17
---

> ## Documentation Index
> The table of contents for this documentation set is at https://cloud.ibm.com/docs/vpc?format=markdown
> The index for all IBM Cloud docs is at: https://cloud.ibm.com/docs/llms.txt
> Use these files to discover more information as needed.

# Why are my VPN gateways or virtual server instances not communicating?
{: #troubleshoot-routing-issues}
{: troubleshoot}
{: support}

When a connection is created successfully, the VPN service adds a `0.0.0.0/0 via <VPN gateway private IP>` route into the default routing table of the VPC. However, this new route can cause routing issues.
{: shortdesc}

* Virtual server instances in different subnets cannot communicate with each other.
* If the VPN gateway is in a subnet that uses the default routing table, it creates a route loop and the VPN gateway cannot communicate with the on-premises VPN gateway.
{: tsSymptoms}

This issue occurs only when the peer CIDR is `0.0.0.0/0`.
{: tsCauses}

To address these routing issues:
{: tsResolve}

* If the virtual server instances in different subnets cannot communicate with each other, create a route with **Delegate** type for each subnet.
* If the VPN gateway is in a subnet that uses the default routing table, complete these steps:

   * Create a dedicated subnet for the VPN gateway.
   * Create a dedicated custom routing table.
   * Associate the dedicated subnet with the dedicated custom routing table.