Fortigate 100D blocking SFTP to remote server

[Ballzack]

Good day

I have the following issue:

The Fortigate is causing the Filezilla SFTP connection to fail to the public ip 105.28.100.177 over port 990.

The connection needs to be established from an internal server.

The last 2 log entries on Filezilla reads:

Status: Connection established, initializing TLS...

Error:   Could not connect to server.

I have created a policy for the internal server, allowing access to all destinations, all ports, and removed all security profiles.

The logs shows that traffic is being allowed through.

I get the same result when testing from a desktop on the network.

I can connect to the site successfully when testing from outside of the network or over 3G.

Not sure where to go from here.

Any assistance will be greatly appreciated.

Thanks.

[ede_pfau]

hi,

and welcome to the forums.

Just a speculation but if you are using FOS v5.4.x or up, open the CLI and

- config sys global

set strong dis

end

and try again. If I'm right I will explain it.

[Ballzack]

Thanks.

Unfortunately no luck after running the command.

[Ballzack]

I am not an expert but do you think this might be an issue with the Fortigate's session-helper?

[Ballzack]

Just updating the resolution. 

Pushed the connection over another WAN interface.

Issue was ISP related.