Perimeter security involves setting up a protective wall around your network. A network must have controlled entry and exit points to monitor network traffic in order to protect its vulnerabilities; without these checkpoints, hackers can slip into a network with little difficulty.

When defining the perimeter, you must be able to distinguish the border between the inside and outside network.

  • Network devices at the perimeter devices of the network are used to implement a portion of the security policy.
  • The security policy which defines how the internal and external networks are connected.