Firewalls
“Border security for network” - some dude online
Firewall is a device or software within a network responsible for determining what traffic is allowed to enter and exit.
Firewall contains devices, technologies, and processes to protect the confidentiality, integrity, and availability of a computer network and the data on it
Firewall can permit or deny traffic based on numerous factors such as:
- Where is traffic coming from or going to?
- What port is traffic using?
- What protocol is traffic using?
There are Stateful and Stateless firewalls.
Stateful - entire connection
Behaviour of connection is based upon the entire connection rather than individual packets. If connection is bad, the entire device will be bocked Better firewall, but uses more resources.
Stateless - individual packets
Static set of rules determine whether individual packets should pass. Device sending bad packets will not necessarily be blocked. Good for DDOS attack. The firewall is less resource hungry but also dumber.