Hey there folks,
I’m trying to figure out how to configure my UFW, and I’m just not sure where to start. What can I do to see the intetnet traffic from individual apps so I can know what I might want to block? This is just my personal computer and I’m a total newbie to configuring firewalls so I’m just not sure how to go about it. Most online guides seem to assume one already knows what they want to block but I don’t even know how/where to monitor local traffic to figure out what I can/should consider blocking.
A firewall by default blocks everything coming from outside going in (without being requested).
Firewalls can also block traffic going out from your PC to the internet. In a company where you need to protect against data exfiltration by employees, and as a last resort safeguard against malware communicating with outside servers, you want that. In that case, a security expert makes a detailed plan of all installed software, to determine what needs to connect from which internal IP to which external IP over which port. Then all other outbound traffic is blocked. This needs to be adjusted constantly, every time a new software is installed or an update changes a software’s requirements. It’s a full-time job.
On a home PC running Linux, that’s absolute overkill. There are no untrusted users in your home and you’re probably not the target for a directed attack by skilled actors. So just leave ufw on default, which blocks all inbound traffic and allows all outbound.