A router is a device that connects two different networks together, when setting up a host machine, it is known as the default gateway. It is used by your company to give you access to other networks, for example the internet. It has a routing table built into it, so it knows which route can be used to deliver network packets. The router is the IP equivalent of a post office sending letters around the world, but instead of letters, IP packets are being transported.

Access Control List (ACL): The router sits on the external interface and uses an ACL so it can also filter the traffic coming into the network by:

  • Port number
  • Protocol
  • IP address

Anti-spoofing: An anti-spoofing filter is placed on the input side of a router interface ...

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