Lecture 10- Network Security

Notes on network security

Firewalls

Internet protocols that allow host anywhere to connect to any other host

Great for flexibility, not so much security

As such, firewalls are used to guard

Essentially a moat, have to enter or leave over a “drawbridge”

Have to connect to the firewall in order to get to the organisations LAN

Simple firewalls will act as a packet router

For example, may stop certain ips from accessing

Dynamic firewalls- monitor TCP connections and open ports based on state of connections

e.g. port 80 opened using port 130, firewall will be around the allow access, but also monitor

Network Address Translation

Allows many hosts within the LAN to share a single external IP address

IPSec

Involves; internet key exchange and IP encapsulating security payload

Virtual Private Networks

Connects separate sites by secure “tunnels”

Not subject to firewalls, passes them