How to fix Azure Plesk FTP not listing directories after inbound and outbound rules, passive mode is set ? Plesk say its someting to do with NAT and routing.

Question

the connection was allowed, and the incoming packet arrived on the Plesk server:

But at the same time, from my test server, packets do not reach the Plesk server:

Not a single packet arrived on the server, that is, it was blocked or not routed/broadcast in front of the Plesk server.   Therefore, I recommend that you contact Azure support and inform them about the issue so that they can check your server's NAT, firewall, routing, and IP address settings.

Answer 1

@Mathias Melen

Thank you for reaching out.

You can try steps mentioned below to see if you are able to pin-point the issue.

1. Check the network security group (NSG) rules associated with the FTP server and see they are blacking the communication. You can use IP flow verify to test network communication.
2. Check the routing table associated with FTP server (if any) to ensure that the traffic is being routed correctly.
3. You have mentioned about firewall in your question above. You can follow the blog here to validate FTP scenarios in Azure Firewall.

If this does not help, please share a rough network diagram of your set-up so that we can suggest any additional troubleshooting steps.