Layer 3 Network Layer

Summary

The network layer moves traffic at an interconnected level using logical network and host IDs. The most common appliance is a router.

How it works

The network layer moves traffic around an interconected network until the data reaches the destination via network or host ID. Once the packet and data arrives the the data link layer can move the traffic to the appropriate node which will know how to manage or unwrap that packet of information.

Firewalls

A firewall is often implemented at layer 3 to limit the going or coming of traffic through a network. The most common way is to use an Access Control List (ACL) to manage permissions.