Outbound IP firewalling of the Go SDK TTN client to the Data API

[xor-gate]

There are a few ports used, the connected 1904 is not even in the list below:

@mellbratt

1. 1700/udp (legacy/Semtech, incl “connection tracking” in iptables)
2. 1883/tcp (Multi protocol packet forwarder)
3. 1900/tcp + 1901/tcp (Go forwarder aka the “new packet forwarder”)

And also ;
1883/tcp or 8883/tcp (MQTT according to https://www.thethingsnetwork.org/docs/applications/mqtt/api.html

So what do we need to add to the firewall then when using the Go SDK for the TTN client?