Perimeter Router, Internal Router & Firewall

First off,

Perimeter Router

You may be wondering..
What the hell is a Perimeter Router and what is its purpose??

A Perimeter Router is a router that is installed on a perimeter segment of a network.

A perimeter segment is an area which connects a network to an untrusted network or an area which is located outside of the corporate firewalls.

Basically, a Perimeter Router is like the door to your house. It sits there and it connects your house (your network) to the world (the whole internet).

Its purpose is to offer and provide minimal protection to the trusted network from any untrusted networks apart from performing packet filtering on traffic.

Due to the fact that Perimeter Routers connect the networks that can be reached via the Internet, they are often the target of hackers trying to exploit any security vulnerabilities.

An unsecured perimeter router would be weak at filtering unwanted network traffic, as well as becoming an easy target for Denial Of Service (DoS) attacks, which can halt the network. Whereas a secured perimeter router can prevent network reconnaissance (the gathering of information to prepare for an attack) and therefore the attacks themselves.

__________________________________________________________________________________

Up next would be...

Internal Router


An Internal Router, a router that is normally set as a form of backup should the first router go down, whether due to an attack or a physical issue. This backup is to ensure that traffic can still flow within the internal network at all times.

Apart from that, it does filtering of traffic for the internal network as well.

__________________________________________________________________________________

And last but not least for the topic is...

Firewall


A Firewall is a set of related programs found at a network gateway server. It provides a certain level of protection on the resources of an internal network from users from other networks.

A Firewall is able to prevent outsiders from viewing private data and users from viewing certain outside resources.