The firewalls are the network security device which monitors well the outgoing and incoming network traffic and even decides whether one must allow the blocking or allowing of specific traffic based on the set security rule standards. They have also been on the first line of the defense in the network security for around 25 years. They even established the barrier between the controlled and secured internal network which can be highly trusted and untrusted on the outside network, as the internet. The firewalls can be both hardware of software.
The different types of the firewalls includes
- Proxy firewall: the early type of the device of firewall termed as the proxy serve as gateway from one major network to other for some applications. They can also proffer the additional functions as the content caching or the security by preventing well the direct connection from outside network. However, this can also lay impact throughout with capabilities and applications which they support.
- The stateful inspection firewall: it allows or even block the traffic which is based on the protocol, port or state. It is known for monitoring all the activities from opening of the connection, until it gets closed. The filtering decisions are also based on the administrator define rules or the context that refers as making use of the information for prior packets or connections which belongs to same connection
- The unified threat management firewalls: the UTM type of device combines typically in the loosely coupled form, and as the function of stateful inspection firewall with the intrusion antivirus or prevention. It can also include some of the additional services and the cloud management. It focuses largely on the ease of access and simplicity.
It must also include some of the standard firewall capabilities as the stateful inspection, the integrated prevention and much more.