Every physical medium has a maximum size of packets it can send. This is called MTU (Maximum Transmission Unit). For Ethernet this is usually 1500 bytes. If we send packets that are larger than 1500 bytes fragmentation is needed. Fragmentation
ARP (Address Resolution Protocol)
ARP is one of the most used protocols and every netwoork engineer should have a good understanding of it. The purpose of ARP is to find out the hardware address for a host for which we know the IP. ARP