Know Network TOPOLOGY


Topology is a design of network.  Two types of topology are-logical and physical topology-we can see and maintain physical topology and we can’t see and rearrange logical topology.
Bus topology=uses a trunk or backbone to which all of the computer on the network connect. Systems connected to this backbone using T connectors or taps. Is cheap and easy to implement, requires less cable, and disadvantages: – whole network may be disturbed whenever any computer have to add or removed, whenever any network cable get break the entire network get disturbed, and it is difficult to troubleshoot.
Ring topology=all devices are connected with each other in a circular format first computer connected with last computer. Advantages=easy to install, troubleshooting easily, whenever we want to add some more computer all network get disturbed, a single break in a cable can disrupt the entire network.
Star topology=most popular topology all computers or devices connected to a centralized device called switch or hub each device need a single cable implemented in wan. Advantages are easy to troubleshoot single computer without disturbing any computer. Disadvantages are it requires more cables.
Tree topology=is a combination of bus and star topologies connected with a backbone advantage-easy to add or troubleshoot. And disadvantages are if the backbone get breaks, the whole network segment get down.
Mesh topology=each computer get connected to each other, more cable requires or more nic popular at wan, wiring get complicated. Disadvantages-requires more cable than other topologies every connection need new nic and cables.

Hybrid topology=whenever two or more topology get connect is called hybrid topology. It is very hard to handle because of it uses different 2 devices and connectors and cables.

Learn Osi Model


                                                            There are seven layer of osi models 
Every layer of osi model is responsible for its works and every layer has own works.
Physical layer:-  it responsible for transmission media how data flow in network, wired or wireless, cable specification, nic, every devices didn’t support this layer some works partially works on data link layer, it is also responsible for encoding, signaling, voltage label, and it defines how my network devices connected physically with each other. Repeaters ,hubs, media convertor are works on physical layer of osi model these devices only can’t able to read the content data so it only know that data in bit form and also transfer it in bit form.
Data link layer:- is the second layer of osi model it is also responsible for the data transmission of data how it flow one place to other it also provides reliable transfer of data on the basis of our physical ip address when data reached at the data link layer is get framed also define network topology, error detection, physical addressing, flow control- if our receiver  didn’t get original speed of data transmission then flow control start running and transmit data in control speed. Bridges and switches are works on data link layer.
Network layer:- is the third layer of osi model how data transmit in network whether it is wired or wireless network layer function are logical addressing, packets, internetworking we connect two or more network with each other it is called internetworking,  routing  it defines the best path of data transfer in network, error handling and diagnosing. Devices who works on on network layer are –router layer 3 switches who perform routing functions.
Transport layer:- is the fourth layer of osi model  it acts as upper layer it is responsible for end to end transmission it provides an function who transmit different data in one time at systems features of transport layer are segmentation, multiplexing many to one and DE multiplexing one to many , process level addressing, connection services, error control in data transmission.
Session layer:- is the fifth layer of osi model it is responsible for software application running and how it communicate features of session layer establishing connections, maintaining connections, synchronizing communication, controlling dialogues, terminating connections. Imp feature-authentication, permission, session layer.
Presentation layer:- is the sixth layer of osi model it Is responsible in presentation of applications like web pages in diff os. Feature-translation, encryption, compressions. It secure data and compresses the data.
Application layer:-it works between software application and other layer works interface it is the seventh layer of osi model how data can flow from one place to another,
Determining  resource availability, syncronizationing.

 Data link layer get partitioned in llc (logical link control) and mac (media access control) Every lan technology uses llc technology.

Learn TCP/IP


*      Transmission Control Protocol/Internet Protocol Every Operating System Use This Tcp/Ip  Tcp/Ip Is Also An Open Forum Model, Most Popular In History Of Networking  Whenever We Want To Create Network Between Different Vendors It Get Possible With Tcp/Ip Model Because Every Networking Devices Uses Tcp/Ip Model.
·         Four Types Of Tcp/Ip Layer:
*      Network Access
*      Internet
*      Transport/Host To Host Layer
*      Application Layer.
·       Working Of Tcp/Ip Model:-
*      Network Access Layer Works as Data Link and Physical Layer of Osi Model.
*      Internet Works As A Network Layer Of Osi Model.
*      Transport or Host To Host  Works as a Transport Layer of Osi Model.
*      Application or Process Works as an Application, Presentation Session Layer of Osi Model.
·       Tcp/Ip Layers And How It Works:-
   Application Layer:- It Is Responsible For Data Transmission Between Two Computers So It Works For The Transmission Of Application Data Of First Computer To Another Computer Application Supports Dns, Dhcp, SMTP, Pop, Protocols.
  Transport Layer:- It Is Responsible For Secure And Error Free Transmission Of Data End To End Works On Tcp Utp Protocols .
    Internet Layer:- It Is Responsible For The Logical Address Of Host’s Ip Address This Layer Handles The Ip Of Host And Ip Or Internetworking And Performs Routing Between Multiple Networks.

   Network Access Layer:- It Is Responsible For Hardware Addressing And Defines Protocols For The Physical Transmission Of Data And It Also Monitors The Exchange Of Data Between Host And The Network Or Also Define Which Protocols Is Running.

Learn Port Security


                                                                                 Port security  in ccna cisco packet tracer:-
ü  Is a feature which helps administrator to protects his internal network:-
ü  Port security remembers the current connected mac address of system to that port.
ü  Allow only that mac address to communicate on that port.
ü  If any other mac address of other nic tries to communicate with it it get shut down or disable  and another mac address get unable to communicate.
v  Port security rules:-
ü  Violation, shutdown, restrict, protect.
ü  Shutdown-by default port get shutdown if any changes were made.
ü  Restrict-get info  to the administrator of network.
ü  Protect-we can also specify any port number or mac for any system so it will works only that port mac.

v  Agar Kisi port pe Kisi mac address ya ip address Ki info dal rakhi hay to uspey bs whi kaam kareyga  aur baki shutdown ho jaengey. 

Learn Routing Things

What is routing

                                                                         What is routing
Routing is a process of sending and receiving packets from source to destination. This works is usually performed by devoted device known as router which is used to find the best path on network. Router Is internetworking device. routing can performed in a lan but it also possible in wide area network. with the help of routing our data can be flow in network from one computer to another.  Router uses a table to  broadcasting message from one place to and finds where is best path to transmit packets a another is called routing table.
Routing protocols and routed protocols:-
Routing protocols- helps routers to finding routes and which path is the best and more efficient to destination.
there are routing protocols are:-
rip-routing information protocol.
Ospf-open shortest path first.
Is-Is-intermediate system to intermediate system.
Igrp-interior gateway routing protocol.
Eigrp-enhanced gateway routing protocol.
BGP-border gateway protocol.
Routed protocol:-
When our data flow in network routed protocols decide which amount of data, size, how many packets have to send one time with best path is called routed protocol.
Routed protocols are:-
Internet protocol.
Novell ipx.
Banyan vines.

Xerox network system. (XNS).

Learn Distance Vector Routing Protocol

Distance Vector Routing Protocol

                                                              Distance Vector Routing Protocol
               Is A Method Which Is Used To Send Packets With Best Path And Speed.
              So Here Distance Is Working Here For Calculating Distance From Its Destination
             Vector Helps Router To Make Direction In For Forwarding Packets.
        Finally Distance Vector Method Routing Protocol Use Works Is:-
             It Uses A Distance Calculation Plus And Packets Outgoing Interface To Choose The Best Path To Go At The Destination.
      Always Send All The Information Made Changes To All Their Neighbors.
Distance Vector Routing Protocol Uses :-
                                                                  Link State Routing Protocol:-
Track The Status And Connection Type Of Each Link. It Finds(Is It Gigabyte, Fast Ethernet, Or Other’s) Who Are Up Or Down.
Link State Protocol Also Known What Is Speed And What Is Cost.
Link State Protocol Also Defines And Auto Configured For Choosing Best And Reliable Path For Transfer Packets.

If Router 1 Wants To Send Packets To Router 5 And The Very Nearest Path Is From Router 2 But It Didn’t Go From There It Choose Second Route It Go From Router 3 And Router 4 And Then Reached At Router 5


It Provides Security To Ip:
Nat And Pat:-
      Network Address Translation (Nat):
      Packet Address Translation (Pat):
Nat Types:
Static Nat:Ek Ek Kr Ke Dalni Padti Hai Ke Kaun Se Kis Me Ho. –  1.1 Wali Ip 1.10 Me Translate Ho Jaey –  1.2 Wali Ip 1.11 Me Translate Ho Jaey
Dynamic Nat: Range Daltey Hai Ki Kha Se Kha Tk Kitney Me Translate Ho. – Ki 1.1 Se Le Kr 1.10 Tk Ki Ip 50.20 Me Translate Ho Jaey.
Pat :
Esmey Port Number Bhi Change Ho Jata Hai.
Pat Types:
It  Only  Support’s  Static: Translate To Translate To

Learn Router

Is A Intelligent Networking Device That Operates On The Network Layer Of The Osi Model.Reference Model.It Maintain Routing Table To Guide Best Route For Transferring Table Packet From One Location To Another.
Interface on router:-

Console port:-router to pc with com port to access router physically.
Ethernet port:-this port is used to connect router to lan.
Auxiliary port:-this port is used to connect router to modem (for dial-up)connection.
Integrated service digital network(isdn):- this port is used to connect router to lan.
Basic rate interface.

Components Of Router:-
Microprocessor:-it is used to decide to best route.

Flash rom:-it contain ios nd bootstarp program.

Dram:-it contain running-configuration.

Nvram:-it contain startup-configuration.

Router configuration modes:-
Cli mode=all configuration mode

Router#>privilege mode.use to view,erase,save,copy etc.

Router#config-t>used to configure router settings.

Router(config)#>global configuration mode.

Some usefull cmd for router:-

>Show running configuration.

>Sh ip route

>to copy=copy running config startup config.

>sh int f0/0=for specific port info           
>ctrl+z = to exit.

Learn Switch

         Is used to connect pc.
   Two types of switches are available:
   Manageable works on network layer of (osi) model.
  Non-manageable works on data link layer of (osi) model.
   Manageable broadcast-when any info aviliable it will broadcast the message to every one.
   Non-manageable unicast-when any info  aviliable in network it will only send to it to specific port no or address.
    When we power on the switch it will auto get the informations of their connected pc like:-mac address,ip address,
    Port number etc.
   When we configure manageable switch:
   We configure:vlan,vlan trunking,vlan routing,vlan pruning etc.
Important notes:
Router to router=serial dte
Switch to pc=roll over cable console port to comport on pc.
Router to pc=vice versa as switch.
To reset password of switch in back of switch u find reset button press that se 1 to 2 sec toi reset.

Learn Router

Router security

router security:-
to setting up password at console port:-
line console port number 0
password 12456
show running config,if when u setting up password at router if any way the power get distruped so u have to saqve your running configuration in nv-rAM.
Copy running config  start-up
It get saved.
But you have successfully saved your password but whenever you type sh running config or sh startup config it will show your password easily.
So you have to secure your password:-
Config-mode=service passwordencryption.  Donnt forget to saved it in starartup config (it will encrypt your password but it not fully secured but there is one more security called as secret.type at config-mode=enable secret don’t forget to save it in startup config.
There is some problem when we write any wrong word:-it get start finding domain automatically.

Solution is here-go to config-mode=no ip domain-loopback.