Exam Essentials

Be able to recognize the different protocols within TCP/IP and be able to define the purpose and function of protocols within TCP/IP.  The TCP/IP stack is made up of several protocols, which each perform such functions as protocol transport, file access, file transfer, and mail transfer. Some of these protocols include TCP, SMTP, IP, NNTP, HTTP, and FTP.

Be able to define the function of common TCP and UDP ports.  You should know how to coordinate protocol name and function with port number. (Refer to Table 3.1 for specific examples.)

Know how to identify IP addresses (IP v4, IPv6) and their default subnet masks.  IPv4 = xxx.xxx.xxx.xxx where xxx is a number from 0 to 255, the default subnet mask is 255.0.0.0 for a Class A address (IP range is 0.x.x.x to 126.x.x.x), 255.255.0.0 for a Class B (IP range is 128.x.x.x to 191), and 255.255.255.0 for a Class C (192.x.x.x to 223.x.x.x).

IPv6 = xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx where x is a hexadecimal digit. IPv6 has no default subnet mask.

Know how to identify the purposes of subnetting and default gateways.  The purpose of subnetting is to divide a network into two or more segments, gaining more addressable segments from a single address space. Default gateways are configured so that a host has an address to send a packet to when it can’t figure out a route to the destination address.

Know how to identify the difference between public and private networks.  Public networks are networks that are open to the general public and, as such, use valid IP addresses that can be “seen” by the general public. The Internet is an example of a public network. Private networks, on the other hand, use addresses that cannot be seen by the general public and are generally not available for public use. Your company’s LAN is an example of a private network.

Be able to describe the main characteristics of VLANs.  Virtual LANs (VLANs) are a feature of network switches that allow machines on different physical network segments to be organized into a virtual segment, or VLAN.