I was studying about how port numbers work and got few questions as follows(sorry but I'm a noob and new to networking stuff but quite interested to learn all this :D )-
1. Where all does firewall exist- Server, client or intermediate routers and bridges.
2.What does it mean to add an exception to a firewall.
3.Opening a port means running a service that we want to be accessible to others. For others to use my running service I need to provide them my port number so that they can connect to it. If I am thinking this right way then, where does firewall come into the picture.
4. When I run a
netstat command on my windows machine then, I see lots services listening on a specific port. I'm not hosting any website so why do I need a service that listens(my pc basically acting as a server). Output looks like this.
Proto Local Address Foreign Address State TCP 0.0.0.0:80 SHIVAM-PC:0 LISTENING TCP 0.0.0.0:135 SHIVAM-PC:0 LISTENING TCP 0.0.0.0:445 SHIVAM-PC:0 LISTENING
What does listening port 80 mean specifically. I'm not hosting any website for http connections.Why is a service running to that listens on port 80.