5.1. Layer 3 Protocols

• The most common protocol in this layer is IPv4.
• Another protocol which is commonly used is ICMP (Internet Control Message Protocol), which is used for various network control tasks.
  • The ping command is the most common use of ICMP.
• Other protocols exist in this layer, and most of them are supported by the Linux kernel, but they are only rarely used.

Written by Shlomi Fish