Ip Addressing And Subnetting - D-Link DGS-3308FG User Manual

8-port Gigabit Ethernet Switch User's Guide
Some filtering requires the manual entry of information into a filtering table:
MAC address filtering – the manual entry of specific MAC addresses to be filtered from the network. Packets
sent from one manually entered MAC address can be filtered from the network. The entry may be specified as
either a source, a destination, or both.
IP address filtering – the manual entry of specific IP addresses to be filtered from the network (switch must be
in IP Routing mode). Packets sent from one manually entered IP address to another can be filtered from the
network. The entry may specified as either a source, a destination, or both (switch must be in IP Routing
mode).

IP Addressing and Subnetting

This section gives basic information needed to configure your Layer 3 switch for IP routing. The information includes how IP
addresses are broken down and how subnetting works. You will learn how to assign each interface on the router an IP
address with a unique subnet.
Definitions
IP Address – the unique number ID assigned to each host or interface on a network. IP addresses have the form
xxx.xxx.xxx.xxx.
Subnet – a portion of a network sharing a particular network address.
Subnet mask – a 32-bit number used to describe which portion of a Network Address refers to the subnet and
which portion refers to the host. Subnet masks have the form xxx.xxx.xxx.xxx.
Interface – a network connection
IP Interface – another name for subnet.
Network Address – the resulting 32-bit number from a bitwise logical AND operation performed between an
IP address and a subnet mask.
Subnet Address – another name for network address.
Note: In a subnetted network, all addresses consist of two parts: an IP address and a subnet mask. The two are
used together and one is meaningless without the other.
IP Addresses
The Internet Protocol (IP) was designed for routing data between network sites. Later, it was adapted for routing between
networks (referred to as "subnets") within a site. The IP defines a way of generating an unique number that can be
assigned each network in the internet and each of the computers on each of those networks. This number is called the IP
address.
IP addresses use a "dotted decimal" notation. Here are some examples of IP addresses written in this format:
1. 210.202.204.205
2. 189.21.241.56
3. 125.87.0.1
This allows IP address to be written in a string of 4 decimal (base 10) numbers. Computers can only understand binary
(base 2) numbers, and these binary numbers are usually grouped together in bytes, or eight bits. (A bit is a binary digit –
either a "1" or a "0"). The dots (periods) simply make the IP address easier to read. A computer sees an IP address not as
four decimal numbers, but as a long string of binary digits (32 binary digits or 32 bits, IP addresses are 32-bit addresses).
The three IP addresses in the example above, written in binary form are:
1. 11010010.11001010.11001100.11001101
2. 10111101.00010101.11110001.00111000
3. 01111101.01010111.00000000.00000001
The dots are included to make the numbers easier to read.
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