DB unit5 #2

Firewalls filter packets by looking at where the packet is coming from, where it is going to, and the application protocols it is using to transfer the data.  (Upadhyay, 2020) These filters can be very helpful for keeping out unwanted traffic. Keeping unwanted traffic out of your network is one of the best ways to keep it secure. Filtering packets from where they come from helps in many ways. If your network has no reason to connect to traffic outside the United states, stopping all packets from other countries from entering the network helps immensely. Watching as to where the packet is going to is also a great way to manage traffic. If you have pieces of your network that shouldn't get outside traffic, filtering out those packets also greatly reduces risk. Lastly is protocol filtering, if you know what kind of protocols the network you are wanting to protect always uses, filtering out all the others will again reduce traffic. Being able to reduce traffic going in and out of your network greatly reduces risk. 

Upadhyay, I. (2020, October 15). Packet Filtering Firewall All You Need To Know In 3 Easy Steps. Jigsawacademy. Retrieved October 22, 2021, from https://www.jigsawacademy.com/blogs/cyber-security/packet-filtering-firewall/

Firewalls can filter network traffic by checking if data packets match specific rules. If the packet adheres to the configured firewall rules, then the packets can pass through. If not, the data packets get blocked. An example would be if the firewall allows all SMPT traffic to pass through but blocks all HTTP traffic. Another way that firewalls can filter traffic is by network address translation or NAT. The firewall looks at whether a connection from the outside can connect to a network resource behind the firewall. If the connection is authorized, the firewall enables the link to be established. Another way firewalls can filter network traffic is by specific IP addresses and IP ranges. For example, a server sitting in the US which mainly serves information to clients based in the US can block traffic from the rest of the world. 

How Does a Firewall Work? (n.d.). Fortinet. Retrieved October 24, 2021, from https://www.fortinet.com/resources/cyberglossary/how-does-a-firewall-work