unit 2 network administation - thesis scientist · pdf fileunit 2 network administation ......

UNIT 2
NETWORK ADMINISTATION
Network administration means the management of network infrastructure devices
(routers and switches). Network administration is the management of PCs in a network.
Goal of network administration:-
The goal of network administration is to ensures that the users of networks receive the information and technically serves with quality of services they
except.
Network administration means the management of network infrastructures devices (such as router and switches)
Network administration compromises of 3 majors groups: 1. Network provisioning 2. Network operations 3. Network maintenance
Network provisioning: - is the primary responsibility of engineering groups and its
consists of planning and design of network which is done by engineer.
Network operations: - it consists of fault, configurations, traffic, all type of
management and it is done by plant facilities group. Its is nerve center of network
management operations.
Network maintenance:- its consists of all type of installations and maintenance
work.

Content:
Addressing and Subnetting: Fixed Vs Variable Masks
Internet Architecture and IP Addresses
Introduction of TCP/IP Internet
Internet Architecture Physical network: computers on the same physical network are physically
connected.
Computers on different physical networks are not physically connected. IP router (or IP gateway): dedicated systems that connect two or more
networks.
Host: end-user system. It connects to physical networks, and there are possibly many hosts per network

The two view of a TCP/IP Internet
Packet Transmission Source Host:
If the destination is on the same physical network, deliver it directly
Otherwise, send it to a router Intermediate Routers:
The destination is not on the same physical network, forward the packet to another router
Final Router
The destination is physically connected to this final router, so send the packet directly to the destination.
How do routers work?
Routers need to find the right routes when forwarding packets. Routers decision is based on the routing information they have Routing table: use destination network, not the destination host;
otherwise, the table will be huge.

IP Address
Overview It is basically an identifier used in the network layer of the internet model to
identify each device is connected to internet or not.
32 bit binary value Unique value assigned to each host Values chosen to make routing efficient Dotted Decimal Notation:
Binary: 10000000 11100110 00000001 00001100
Dotted decimal notation: 128.230.1.12 The IP address consists of a pair of numbers:
IP address =
The network number portion of the IP address is administered by one of three
Regional Internet Registries (RIR):
American Registry for Internet Numbers (ARIN): This registry is responsible for the administration and registration of Internet Protocol (IP) numbers for North
America, South America, the Caribbean, and sub-Saharan Africa.
Reseaux IP Europeans (RIPE): This registry is responsible for the administration and registration of Internet Protocol (IP) numbers for Europe, Middle East, and
parts of Africa.
Asia Pacific Network Information Centre (APNIC): This registry is responsible for the administration and registration of Internet Protocol (IP) numbers within
the Asia Pacific region.
The division of an IP address into two parts also separates the responsibility for selecting
the complete IP address. The network number portion of the address is assigned by the
RIRs. The host number portion is assigned by the authority controlling the network. As
shown in the next section, the host number can be further subdivided: This division is
controlled by the authority that manages the network. It is not controlled by the RIRs.
Classful Addressing Scheme (The original scheme, didnt last long) In this scheme the address space is divided into 5 classes as shown below
Above class support unicast address schemes.

Properties of the classful addressing scheme?
They are self-identifying: the boundary between netid and hostid is self-explained from the address. This can benefit routing because the entries of routing tables
store mainly use netid, not the entire IP address.
Class A:-
Range (1-126)
1st bit is always 0
Range of network nos 1.0.0.0 --- 126.0.0.0
No of possible network is 127 and out of this 1-126 is used & 127 & 0 is not used.
No of possible values in host portions is 16,777,216 (256*256*256 )
Advantages:- used for large network
Disadvantages: - millions of class A address are wasted.
Class B:-
Range (128-191)
Always 1st two bits is 10
Nos of possible networks 16,384 blocks (64*256)
No of possible values in host portions is 65,536(256*256)
Advantages: - used for midsize network
Disadvantages: - many of class B address are wasted.
Class C:-
Range (192-223)
Always 1st three bits is 110
Nos of possible networks 2,097,152 blocks (32*256*256)
No of possible values in host portions is 256
Advantages: - used for small network
Disadvantages: - nos of address in class C is smaller than the needs of mosts organizations.
Class D :-
Range (224-239)

Always 1st Four bits is 1110
It is used for multicast.
Class E :-
Range (240-255)
Always 1st Five bits is 11110
It is used for research purpose.
PROBLEMS OF CLASSFUL ADDRESSING SCHEMES:-
In classful addressing schemes each class is divided into a fixed no of blocks where each
blocks have affixed size
CLASS A:-
Total 128 blocks
1st block -0.0.0.0---------0.255.255.255
Last block 127.0.0.0-----------127.255.255.255
Private address range 10.0.0.0-------10.0.0.255 (1 block)
so total no of block used is 125.
So main disadvantages is that million of class A address are wasted because no of address
in each blocks is 16,777,216
Class B
Total blocks 16384(out of that we used only 16,368)
Each blocks contains address -65,536
16 blocks are reserved for private addressing.
Range 172.16.0.0 ---------172.31.255.255
Class C
Total blocks 2,097,152 (out of that we use 2,096,896)
256 blocks are used for private addressing.
Private address range 192.168.0.0 ---------192.168.255.256
Each block contains 256 addresses.

Class D
It contain 1 block
Used for multicasting
Class E
Its contain 1 block
Used for reserved address.
Reserved address prefixes
a) 10/8 10.0.0.0 - 10.255.255.255
b) 172.16/12 172.16.0.0 - 172.31.255.255
c) 192.168/16 192.168.0.0 - 192.168.255.255
d) 169.254/16 169.254.0.0 - 169.254.255.255
Special Addresses
255.255.255.255: Limited broadcast (local net)
0.0.0.0: this host. Can only be used as source address. It is used during bootstrap before a computer knows its IP address. 0 means THIS.
net + all 1s: directed broadcast for net
127. Anything (often 1): loop back.
Reserved IP addresses
A component of an IP address with a value all bits 0 or all bits 1 has a special
meaning:
All bits 0: An address with all bits zero in the host number portion is interpreted as this host (IP address with =0). All bits zero in the network
number portion is this network (IP address with =0). When a
host wants to communicate over a network, but does not yet know the network IP
address, it can send packets with =0. Other hosts in the
network interpret the address as meaning this network. Their replies contain the
fully qualified network address, which the sender records for future use.
All bits 1: An address with all bits one is interpreted as all networks or all hosts. For example, the following means all hosts on network 128.2 (Class B address):
128.2.255.255 This is called a directed broadcast address because it contains 128.2.255.256 both a valid
and a broadcast .
Loopback: The Class A network 127.0.0.0 is defined as the loopback network. Addresses from that network are assigned to interfaces that process data within
the local system. These loopback interfaces do not access a physical network.

Unicast address: - its used to communicate from one source to one destination.
Multicast Address: - its used to communicate from one source to group of destination.
& it can be used only as destination address only.
Broadcast address: - communication is from one to all
Note: - address space is 2 power N
Where N is no of bits
An IP address are designed with 2 level hierarchy
1) netID 2) hostID
Network ID (netID): - the hosts that populates that networks shares those same bits
called networks bits.
Host ID:-these are unique identifier of each hosts within that network.
Network address:-a network address is an address that defines network itself it cannot
be assigned to a host.

unit 2 network administation - thesis scientist · pdf fileunit 2 network administation ......

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