Chapter 5

Subnet Mask

A 32-bit address mask used in IP to indicate the bits of and IP address that are being used for the subnet address.

Class A

A Class A address has four octets. The first octet is between 1 and 127. The other three octets are used for host addressing. A Class A network can have 16,777,214 hosts.

Class B

A class B address has four octets. The first octet is between 128 and 191. The first two octets are used to identify the network. The last two octets are for host addressing. A class B network can have 16,384 networks and 65,534 hosts.

Class C

A class C address has four actets. The first octet is between 192 and 223. The first three octets identify the network. The last octet is for host addressing. A class C network can have 2,097,152 networks and 254 hosts.

Class D

A class D address has four octets. The first octect is between 224 and 239. Class D is used for multicasting.

Class E

A class E address has four octets. The first octet is between 240 and 255. Class E I addressing is reserved.

octet

A decimal number in the range of 0 to 255 that represents 8 bits.

Public IP Address

All IP addresses except those reserve for private IP addresses.

DHCP Range

Dynamic Host Configuration Protocol range. A contiguous list of IP addresses in a DHCP pool.

DHCP

Dynamic Host Configuration Protocol requests and assigns an ip address, default gateway, and DNS server address to a network host.

DHCP Server

Dynamic Host Configuration Protocol(DHCP) is a set of rules for dynamically assigning IP addresses to devices on a network. A DHCP server manages and assigns the IP addresses and ensures that all IP addresses are unique.

Private IP Address

IP address that is reserved for internal network use only and cannot be routed on the internet. The ranges for IP addresses are 10.0.0.0 to 10.255.255.255, 172.16.0.0 to 172.31.255.255, abnd 192.168.0.0 to 192.168.255.255.

IPv4

Internet protocol version 4. The current internet protocol version.

Nat

Network address translation. The process of re-writing the source or destination address of IP packets as they pass through a router or firewall so multiple hosts on a private network can access the internet using a single public IP address.

RFC

Request for comments. A document series used as the primary means to communicate information about the internet. Most RFCs document protocol specifications such as Telnet and file Transfer protocol, but some are humorous or historical. RFCs are available online from numerous sources.