DDNS, what ports needs to be open?

[Mada]

What port/protocoll needs to be open for the DDNS function?

Thanks

[eastavin]

None as ddns originates inside the firewall. Caveat is as long as your firewall is not set to deny outbound traffic.

[Mada]

My firewall is set to deny outbound traffic. I have opened ports for SoftEther VPN. I can not find any documentation on the DDNS function. UDP Port 53?

Thanks

[gvilkas]

Wow. Do you have serious security challenges? Try port 80 first, 8080 second. 1080 is an unlikely long shot. After that if it's still not working best to review your outbound firewall logfiles and see where it is trying. If you still can't figure it out just disable it and subscribe to a ddns service and follow their instructions.

[thisjun]

Which side information do you want to know?
Server side? Client side?

[Mada]

It is the softether server side. Unless I give softether process free outbound connectivity the server is unable to register DDNS name.

Thanks

[thisjun]

SoftEther use HTTPS for DDNS registration.

[Mada]

Thank you!

I am allowing outgoing tcp and udp 443 only and it seems to work well. Incoming tcp 5555 and udp 500 and 4500 only.

Do you know what SE uses port 40000 for?

[Pandamon]

thisjun wrote:
> SoftEther use HTTPS for DDNS registration.

Meaning 443.

[Mada]

Yes, thank you. I opened 443 and it works. Apart from udp and tcp 443 I only have incoming tcp 5555, udp 500 and 4500 allowed.

I can see that that softether (server to server) tries to consistently connect from port 40000 witch is blocked by FW. But it works anyway.

Just curious about this port. SE tries to use other ports as well but not consistently.

[thisjun]

Is the port 40000 UDP?
If so, I think it's to use UDP acceleration or NAT-T.