Other Network Layer Features

Other Network Layer Features

1. Domain Name System (DNS)

2. Address Resolution Protocol (ARP)

   • Method by which any host or router on a LAN can dynamically learn the MAC address of another IP host or router on the same LAN
     • “if this is your IP address, please reply with your MAC address.”
     • Each time a host or router needs to send a packet encapsulated in an Ethernet frame, it first checks its ARP cache for the correct IP address and matching MAC address
       • Hosts and routers will let ARP cache entries time out to clean up the table, so occasional ARP Requests can be seen.

3. Ping

   • Packet Internet Groper) uses the Internet Control Message Protocol (ICMP), sending a message called an ICMP echo request to another IP address.
     • The computer with that IP address should reply with an ICMP echo reply.