Presentation on theme: "Firewalls What are they and what do they (not) do?"— Presentation transcript:
Firewalls What are they and what do they (not) do?
Firewalls What is a firewall? –A firewall is any mechanism that acts to restrict access to a network according to a set of defined rules. –Function as front doors to a network.
Firewalls How do they work? –By inspecting traffic that travels across/through them according to the policy thats been set.
Firewalls How are they set up? –Act as a go-between for any two given networks The Internet Firewall Your Network Have Rules been met? Yes? You can go. No, you cant.
Firewalls –Two main types Routing based filters –From where did you come? –Where are you going? –Dont care what you do once you get there. Content based filters –What are you trying to do? –Not as common as Routing based because its harder to implement successfully –Steps have been taken to create hybrids
Firewalls Two ways to approach the rule sets: –Allow all except what is defined as unwanted Place roadblocks/watch gates along a wide open road. –Deny all except what is defined as wanted Build a wall and carve paths for everyone you like.
Firewalls Problems: –Firewalls as filters can be considered for most part to be infallible... but as a security measure? They can only enforce rules (generally static) The Internet Firewall Your Network
Firewalls Crunchy on the outside, but soft and chewy on the inside. Your network Your firewall The Internet Your hacker Your trusted friends who arent security aware Step 1 Step 2
Firewalls Conclusions –People dont just put up a thick front door for their sensitive belongings, you shouldnt for your network either. –Firewalls are an effective start to securing a network. Not a finish. –Care must be taken to construct an appropriate set of rules that will enforce your policy.