1. Firewalls

2. Intro to Firewalls Basically a firewall is a barrier to keep destructive forces away from your computer network

3. What Firewall S/W Does Filters the information coming through the Internet connection into your private network or computer system. If an incoming packet of information is flagged by filters, it is not allowed through.

4. Packet Filtering Packets (small chunks of data) are analyzed against a set of filters. Packets that make it through the filters are sent to the requesting system and all others are discarded.

5. Firewall Configuration Firewalls are customizable. This means that you can add or remove filters based on several conditions. Domain Names Protocols Specific Words / Phrases

6. IP Addresses Each machine on the internet is assigned a unique address called an IP Address. Example: 216.27.61.137 If a certain IP address outside a company is reading too many files from a server, the firewall can block all traffic to or from that IP address.

7. Protocols Protocol is the pre-defined way that someone interacts with a service. The HTTP is the Web’s protocol. – IP: Internet Protocol – FTP: File Transfer Protocol

8. Words and Phrases The firewall will sniff (search through) each packet of information for an exact match of the text listed in the filter. You can include as many words, phrases, variations as you need. You could instruct the firewall to block any packet with the word “X-rated” in it (but would not catch “X rated” – no hyphen).

9. Why Firewall? You still need to install anti-virus software. Spam is going to get through as long as you accept e-mail. Businesses use them to fight DDoS attacks. It also stops anyone from logging onto a computer in your private network.

10. DDoS - Defined Distributed Denial of Service. An attempt to make a computer resource unavailable to its intended users. Overloads the target machine with external communications requests, such that it cannot respond to legitimate traffic quickly or at all.