P2S VPN Client unable to reach any other VPN Clients

Hi @Ryan Parino

Welcome to the Microsoft Q&A Platform. Thank you for posting your query here.

It is understood that the device with IP 12.11.10.3 is not able to communicate with the devices having IPs 12.11.10.2, 12.11.10.130, and 12.11.10.131, while it can communicate with the device at 10.0.0.4 via a Point-to-Site VPN.

Here are a few steps you can take to troubleshoot and potentially resolve this issue:

• Check NSG Rules: Verify if there are any NSGs associated with the subnet or individual network interfaces of the devices. Ensure that rules are in place to allow traffic between the devices you want to communicate.

Verify Route Tables: Make sure that the route tables associated with the subnets are correctly configured. Misconfigured route tables might cause traffic to be routed incorrectly.

Check the VPN Configuration: Confirm that the VPN client configuration on the device with IP address 12.11.10.3 is correct. Make sure it’s set up to route traffic appropriately.

Verify the Firewall Rules on the Device: Check for any local firewall rules on the device with IP 12.11.10.3 that might be blocking traffic to or from other devices. Ensure that the firewall rules are not overly restrictive.

Inspect IP Address Conflicts: Verify that there are no IP address conflicts in your network. IP conflicts might cause connectivity issues.

Verify Subnet Configuration: Ensure that all devices are in the same subnet or that appropriate routing rules are set up if they are in different subnets.

Check VPN Gateway Configuration: Confirm that the VPN Gateway configuration does not have any restrictions or settings that could affect communication between specific IP addresses.

Review Connection Logs: Check the logs for the VPN Gateway and the individual devices to identify any errors or messages that might provide clues about the connectivity issue.

Test Network Connectivity: Use network diagnostic tools (such as ping, traceroute, or telnet) to test connectivity between devices. This can help identify where the connectivity issue is occurring.

Update Device Network Drivers: Ensure that network drivers on the device with IP 12.11.10.3 are up to date. Outdated drivers can sometimes cause network issues.

Kindly let us know if the above helps or you need further assistance on this issue. If the answer is helpful, please click "Accept Answer" and "Upvote it."