Firewalling Basics

44Net Connect and Security

44Net Connect provides every device with a public facing IPv4 address, and does not inspect, filter, or block any traffic directed towards 44Net devices. Devices with publicly routable IP addresses face a constant barrage of traffic from various scanners and bots on the internet. Some of them are malicious, and correctly configuring your firewall is a key part of defending against them.

What does a firewall do?

At its most basic, a firewall inspects incoming and outgoing packets, and based on its set of rules, decides whether each packet should be allowed through, dropped, or diverted. Rules may consider a packet's source and destination IP, source and destination interface, port, protocol (TCP vs UDP), or various special flags that may be set. Basic firewall usage is primarily concerned with source/destination IP, source/destination interface, and port. There are several goals we can achieve via firewall rules: allow outside connections to public-facing services, block outside connections to private services, and in case your device is compromised, block outgoing malicious traffic originating from your device.