Transcript LAN Chapter 5 - Valencia College

LAN Chapter 5
Protocols
IP Planning
 An IP address contains 32 bits or total of 4
octets (32\8).
 Each bit of the 32 bits can be a member of
one and only one of the following sections:
– Network
– Host
– Subnet
IP Planning
 What is the Network Section?
– A group Identifier (compare to area code number)
 How many bits should be under the Network
section?
– Depends on the size of the organization
• Depending on the size of the organization and potential
growth, one of the following classes can be obtained
from the InterNIC Organization: A, B, or C.
8 bits
16 bits
24 bits
IP Planning
 What is the Host Section?
– Group of individuals within the same network.
 How many bits should belong to the host
section?
– 32 – Network bits
 How many hosts can a Network have?
– (2 ^ Number of host bits ) - 2
IP Planning
 What is Subnetting?
– Process of subdividing a single class of network into
multiple, smaller networks.
 Why do we need it?
– Organization, Control, and Ease of management.
 Who does it?
– The Network Administrator of the organization.
IP Planning
 How is Subnetting Done?
– Borrow bits from the host section and move
them to the “Subnet” section.
 How many bits should I borrow?
– Depends on how many subnets you want to
create (this figure is determined by your
organization’s needs and structure)
IP Planning
 What are the rules?
– Number of subnets created =
2 ^ (Number of bits borrowed from the host section)
– Number of subnets Available =
2 ^ (Number of bits borrowed from the host section) – 2
– Number of hosts created per subnet =
2 ^ (Number of bits remaining under the host section)
– Number of hosts available per subnet =
2 ^ (Number of bits remaining from the host section) – 2
IP Planning
 Why are we loosing 2?
– Network Identifier.
– Network Broadcast Address.
 What is a network Identifier
– The first IP address in a network, Known as the cable
identifier, Represents the entire network, All host bits
are turned off (0s).
 What is a Broadcast Address?
– The last IP address in a network, used to communicate
with all the hosts in the network, All host bits are
turned On (1s).
IP Planning
 What are some of the problems associated
with Subnetting?
– Loosing IPs.
– The outside world does not have any
knowledge of our Subnetting plan.
 How can we fix those two problems?
– Loosing IPs.  Router Configuration.
– Subnetting Plan.  Subnetmask
IP Planning
 How is it written?
– All bits under the network and subnetwork sections
are turned on (1s).
 What is Default Subnetmask?
– The subnet mask that will be used if you do not
specify one in your TCP/IP configuration.
• 255.0.0.0 for Class A
• 255.255.0.0 for Class B
• 255.255.255.0 for Class C