Transcript Subnetting - Edinboro University of Pennsylvania

Subnetting
A distributed networks savior
By: Mike Guantonio
What are public and private
Addresses?

Public addresses are
addresses of the
outside world


Given to us by the ISP
Private addresses are
addresses inside the
network that are not
seen by the outside
world.
When do we use Public
Addresses


To set up a link to the outside world.
To set up routers in different parts of a work
area.
Why do we need Sub-networks



Running out of IP addresses
Waste of IP addresses
Private numbers that can be used in any
organization
Why do we subnet?

With private networks we can assign a block of
addresses to various groups





Finance
Marketing
Help Desk
Development
This becomes more apparent with the
introduction of VLans
What is the advantage of subnetting?



We subnet large vs. small networks
A subnet breaks a network into smaller more
manageable pieces
Much like how the phone company breaks
down the telephone numbers with area
codes.
Can different subnets “talk” to
each other?



No
But with the help of switches and/or routers
its possible
Nodes in the same subnet can communicate
independently without any extra protocols
needed.
Classes of Networks


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Class A – N.H.H.H
Class B – N.N.H.H
Class C – N.N.N.H
Class Ranges

Class A – Range10.0.0.0 – 10.255.255.255

Class B – Range 172.16.00 –172.31.255.255
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Class C – 192.168.0.0 – 192.168.255.255
How to subnet
What do home routers
do?

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
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Most routers will dish out an address of
192.168.1.(2-255)
This is not the address that other computers
see
The reason for this is so that multiple
computers can connect to the network
without needing various IP’s
This is called NAT or PAT depending on the
protocol.
Works Cited

Chapman, Bill, and Allan Johnson, Rick Graziani, Elaine Horn,
Andrew Large, Antoon W. Rufi. CCNA 1 and 2 Companion
Guide. 3rd . Indianapolis,
Indiana: Cisco Press, 2005.