Solaris™ 8 Network Administrator Certification Training Guide

INTRODUCTION TO PORTS AND SOCKETS

Every layer in the TCP/IP network uses some kind of mechanism to distinguish its services. In the previous chapters, you learned about MAC and IP addresses. A MAC address is a 48-bit number and is a unique address used to distinguish hosts at the Data Link layer level. All communication taking place at the Data Link layer level is done using MAC addresses. When the IP layer needs to send data to some other host on a network, it must resolve the destination IP address to its MAC address using the ARP protocol.

In the same way, the Network layer (IP layer) uses IP addresses to distinguish different hosts on a network. An IP address is a 32-bit number and must be unique for all connected networks and hosts. Hostnames ...