L3- and ARP-based attacks
In this section, we will discuss ARP and IP attacks. Let's start with ARP poisoning, which is also known as ARP spoofing.
ARP poisoning
ARP is a protocol that resolves the destination MAC address from the destination IP address. Note that we discussed this in Chapter 2, Network Protocol Structures and Operations.
ARP poisoning (also known as ARP spoofing) is a type of attack that involves sending malicious ARP packets to a default gateway on a LAN in order to change the gateway ARP table.
The attack is used to alter the host-under-attack MAC address in the gateway ARP cache. This is so that instead of sending packets to the host under attack, the gateway will send these packets to the attacker that can copy their content.
Once the default gateway has changed its ARP cache with the faulty MAC entry, all of the traffic sent to the host under attack travels through the attacker's computer, allowing the attacker to inspect or modify it...