I've recently read a Microsoft Technet article on how Windows Firewall works. The author of the article uses concepts like 'solicited network traffic' and 'unsolicited network traffic' for a machine. I guess I don't fully understand the concept of those.
In relation to TCP protocol, is the solicited traffic a traffic that was initiated by a local machine?
In relation to UDP protocol, is there even sth like a solicited/unsolicited traffic or is all traffic unsolicited?
What about other protocols? (+can Windows Firewall filter those other protocols)
Yes, solicited traffic is traffic that was initiated by you. Solicited traffic automatically gets a pass, no matter the port, because you initiated it. This alleviates a lot of the headaches of traditional firewalls, e.g., having to open up ALL the ephemeral ports, because Windows Firewall will keep track of the session state for you.