I must say, I don’t post much here on the forums because 1) You guys are great at answering questions, and 2) OpenSUSE is a pretty rock solid and easy to use distro. However, I do have a question regarding firewalls. I’ve been using linux for a long time, but never had to deal with a firewall. I’ve always just disabled it. In the Windows world, there’s usually a prompt whenever an application tries to access the network in which you can choose to deny the program access or allow it access. Linux is way different (Fedora’s SElinux troubleshooter and openSUSE’s fireall programs)
I have a chromecast right now that is unable to be detected by my Linux computer running openSUSE 13.1. When I disable the firewall, it works fine.
As far as I know, the chromecast just requires, "Enable Multicast, UPnP, & IGMP in your router settings. " So I’m assuming it uses multicast, UPnP, and IGMP. However, I’m not exactly sure how to allow these services in OpenSUSE.
This link is for Ubuntu, but is pretty confusing: How can I use Chromecast - Ask Ubuntu
So I guess I have two questions: One, how can I start troubleshooting stuff like this on my own. How can I see network traffic and see exactly what is getting blocked so I can see if I can unblock it? And two, once I find out what’s getting blocked how do I go into the firewall and allow these items?