[Bug]: ADS Driver doesn't seem to support connections via VPN

[chrisdutz]

What happened?

When trying to connect to an ADS device via a VPN connection, the remote device seems to simply hang up.

Version

v0.13.0-SNAPSHOT

Programming Languages

• plc4j
• plc4go
• plc4c
• plc4net

Protocols

• AB-Ethernet
• ADS /AMS
• BACnet/IP
• CANopen
• DeltaV
• DF1
• EtherNet/IP
• Firmata
• KNXnet/IP
• Modbus
• OPC-UA
• S7

[IsmoLeszczynski]

Just as additional information relating to this, I've been working on a solution and testing it via an OpenVPN connection successfully, so some VPN connections work.

What I did have issues with was connecting via IP instead of hostname, don't know that's related - using IP caused the PLC to terminate the connection immediately, but using hostname worked fine. This was a bit puzzling, but I haven't used ADS enough to say is this as it should be.

[chrisdutz]

I recently setup my test-environment to be only reachable via VPN (Unify Gateway) ... so when using the built-in MAC VPN (L2TP over IPSec) and using an IP I was having the remote simply hang up ... if this is just a documentation problem, then I would be super happy ;-)

[chrisdutz]

I think the problem might be related to my device getting an IP address that is generally not reachable from the ADS device. So the device has the IP 192.168.23.20 and a netmask for 255.255.255.0 ... my local dialin computer has an address of 192.168.2.6 ... I would probably try to configure the VPN to give my client an IP on the remote network instead of using the VPN tunnel as default gateway.