introduction to networking (yarnfield) ip addresses
TRANSCRIPT
Introduction to networking(Yarnfield)
IP addresses
Objectives Define an IP address Describe IP address classes Describe network and host portions of an
address Describe what a broadcast address is used for Describe what private IP addresses are used
for
The Internet Protocol Every machine MUST have a unique address
This is referred to as the IP address This address is used to route packets of
information using TCP/IP to a specific machine The address is made up of two parts a network
address and a host address To find your IP address type ‘ipconfig’ into a
command line window
The network part of the address Is used to route the packet to the correct
network i.e. 194.66.170 would direct the packet to one part of
the Staffordshire university network Once the packet is within the network
The host part of the IP address is important to direct the packet to actual machine within that network
The network address size changes depending on the size of network in which the host is connected. Class A, B, and C
All network addresses are issued by InterNIC (http://www.internic.net/) to ensure that all address attached to the Internet are unique
Host addresses
Address representation (IP v4) An IP address is a 32 bit value
In theory this gives over 4 billion possible addresses In reality the actual number of available addresses is a
lot less than this An IP address is represented by dotted decimal
numbers In reality within the network the values are represented
by binary As humans we do not use binary, as these are
difficult for us to remember Also it is very easy with a large number sequence to
make mistakes when setting the IP address
Address classes
Address 127.*.*.* is a reserved address to indicate loop back i.e. communicate with the device sending the
request
Address classes
Address classes
Broadcast address Is an IP address which is used when
communications are required with ALL of the devices with a certain network address This value is 255 in the host part of the address
Private IP addresses A number of IP addresses have been reserved
for private use on local LANS If you setup a Microsoft windows network it will
default to a class C private network IP address
Subnets Subnets allow for a host part of a host address
to indicate a subnet These are smaller local networks within the major
network The advantage is that this allows a packet to be
more tightly direct to a host The disadvantage is valuable host addresses are
used to create a subnet More details about subnets will be given during the
course
Subnet address Also 32 bits in length Indicates which part of the IP address is the
network, and which part is the host Each class has a default subnet mask Class A - 255.0.0.0 Class B - 255.255.0.0 Class C - 255.255.255.0 Example
192.5.5.35 255.255.255.224 192.5.5.35/27
You cannot skip bits!
Exercise1. What are the two parts that make up an IP
address?2. What are the five classes of IP address, and
which ones can be commercially used?3. For an IPv4 IP address, how many bits are
used and what is the total amount of addresses that can be derived?
4. What is the purpose of a subnet?5. What will a broadcast IP address actually do?
Summary IP addresses are used to route packets of data
throughout a network IPv4 uses 32 bits Hierarchical in nature Classes are A, B, C, D and E Classes A, B and C are used commercially Broadcast addresses reach all host machines
on a network
Questions... ...are there any?