Wireless Networking Concept

Wireless Networking Concept

Wireless networking means connection without wire and cable is not use as medium for connection but RF (Radio Frequency) waves are use for connection. By default RF waves cannot carry bits or data. We have to use Shift Keying method to carry data or bits using RF waves. Shift Keying method means to disturb the waves or to change the characteristics of RF waves.

Characteristics of RF waves are:-

1. FM (Frequency Modulation)

It means number of waves generate per second. It is absolute measurement. Its unit is Hertz. Maximum 2.4 GHz is allowed for general purpose and 5 GHz for special purpose like Defence.

2. Amplitude

It means height of waves. It require lot of power. It is measure in Watt. It is also absolute measurement.

3. Phase

It means difference between two waves. It is relative measurement and its unit is Degree.

There are 3 organizations which can set the standards for wireless networking and these organizations can work in hierarchical manner:-

1. ITU-R (International Telecommunication Union - Radiation)

It can set the rules and boundaries for indoor and outdoor. For eg:- 2.4 GHZ

2. IEEE (Institute of Electrical and Electronic Engineers)

It work within boundary of ITU-R and set the wireless networking standards. IEEE 802.11x (802.11g) is wireless netwoking standard.

3. Wi-Fi Alliance (Wireless Fidelity)

It is certification body which can certify the wireless networking devices.

Wireless Networking Devices:-

1. Wireless NIC or Data Card

It is use to receive waves, it is wireless transceiver.

2. Access Point

It is wireless transmitter, it can generate the RF waves.

3. IR (Intentional Radiator)

It is a device which can generate waves or radiation intentionally. Eg:- Microwave

4. EIRP (Equivalent Isotropical Radiation Power)

It means anything which can generate waves or energy in all the directions equally in 360 degrees. Eg:- Sun or Solar Energy

5. Antenna

It is use to send and receive waves between the different wireless devices.

Types of antenna:-

1. Omni-directional antenna

It can send waves in all the directions but it can cover very small area. Eg:- Access point antenna.

2. Semi-directional antenna

It can send waves in one direction only but it can cover very large area like a street lamp.  Eg:- Yagi antenna use on towers.

3. Hi-directional antenna

It can cover long distances. Eg:- Dish antenna.

NOTE: WEP, WPA, TKIP etc are the protocols use for wireless security.

Function of Access Point:-

1. Access Point       (Wireless hub)

2. DHCP server

3. Repeater

4. Bridge   (It can connect another Access Point)

5. NAT

6. Routing

Printer

Printer

Printer is an output device which is use to get the hard copy of our data.

Requirements in the printing process :-

1. Print device    -       It means actual hardware

2. Print driver     -       It is software which can run hardware

3. Printer           -       It is software interface between user and print device.

4. Print server     -       It is computer which is use to manage the printing jobs or computer on                               which print device is connected physically.

Printer permissions:-

                                        Allow         Deny

        Print                         

        Manage Printer

        Manage Document

NOTE: By default everyone has print permission.

Options in Printer :-

1. Spooling         It means documents will be copy to the spool folder on print server and printing will be done automatically when print device is available.

2. Pooling      It means transfer of print job automatically to another printer.

Now we can select more than one ports at a time.

 

3. Print Redirection      It means pooling on another server.

NOTE: We have to create virtual port for all the printers.

 

4. Additional drivers   This option is use to add the drivers for the different version of windows so that client will not search any driver for print device.

5. Separator page      It is a special page between all the documents in the print tray after the printing is done, it is use to differentiate the documents. There are 4 types of separator page.

Network Printer

It is a printer which is not connected to the local computer or which has built-in NIC.

There are different methods to install network printer.

RUN   \\servername    -> Printer   -> Connect

Internet Printing

It means printing through web browser. It is feature of Server OS only and it is part of IIS.

DFS (Distributed File System) Hyper-V (Virtualization)

DFS (Distributed File System)

It is feature of Windows server 2000,2003,2008 and 2012. It is use to manage all the sharefolders of the different file servers. It is use for very large networks. We have to install DFS in Windows 2008 and 2012. We must install file service before the DFS feature.  It is use centralize administration of the different sharefolders, we can create links or shortcuts of the existing sharefolders without assigning any drive letter such as home folder.  Users can also easily access any folder without knowing the actual path of folder.

DFS Namespace or DFS Root

It is a sharefolder to create DFS Link. There are 2 types of DFS Namespace :-

1. Standalone DFS Namespace      It can be use in the domain or workgroup network. It cannot replicate.

2. Domain DFS Namespace     It can be use in the domain and it can replicate.

DFS Link

It is shortcut of the existing sharefolder. It can be create within DFS Namespace.

NOTE: There is no limit to create Namespace and Link in DFS.

NOTE: DFS Replica or Target can be use for fault tolerance in DFS.

Hyper-V (Virtualization)

It is built-in feature of Windows 2008 R2 and higher versions of Server OS. It is not compatible with VMware. It requires 64 bit CPU with executable bits and VT feature must be enable in BIOS or CMOS setup.  It is use to create virtual machines. We can use Virtual Network Adapter for network connection and we can select Private, Internal and External.

Virtualization is use for cost saving, for testing purpose, for training purpose, for better fault tolerance etc.

We can also use Microsoft Virtual PC, Oracle Virtual Box etc. for virtualization.

What is ICS (Internet Connection Sharing)

ICS (Internet Connection Sharing)

It is default feature of Windows 98 II^nd edition and higher versions and can be use in workgroup also.

It is use to share Internet connection, it is slow, it use dialup connection, it can be use for small network, we cannot use DHCP server and maximum 253 clients are possible because Network ID is always 192.168.0.0

Nowadays, we can use any network ID.

NAT (Network Address Translation)

It is use to share Internet connection, it is mostly configure on Router but we can also configure on Windows server. It can also be use in the workgroup network. It is lease line connection, it is faster, we can use any network ID, we can use DHCP server, no limit for the number of clients and it can be use in very large network. It is use to manage IP addressing , to save IP address etc.

We need 2 NICs in NAT server.

Proxy Server

It is a software use to share Internet connection and for Internet security. It can be install on client OS also in the workgroup network or domain network.  We can apply GPO for automatic configuration in the client machine for the domain network.

Proxy server can check the websites which are browse in our network and we can also block particular URLs.

Example :-  ccproxy, WinGate, Win Proxy, Web Proxy, WebSense, MS-Proxy etc. 

Windows Clustering or Failover Cluster

Windows Clustering or Failover Cluster

Cluster means the combination of hardware.

Windows cluster is feature of Enterprise edition and Datacenter edition only, not for Standard edition and Web edition.

We need domain network and member servers

Clustering service can be use for Web server, Email server, File server etc.

We have to install same service on both member servers, we need atleast 2 NIC on both member servers and we have to configure Quorum or SAN (Storage Area Network).

We have to create cluster name and virtual IP which will be use by end users.

Networking Devices

Networking Devices

1.Hub  It is networking device use to connect the different computers of same network ID, it cannot stop broadcasting, it work on layer 1 of OSI model, it has single broadcast domain and single collision domain.  There are 2 types of hub :

i)Passive hub   It has 4 ports

ii)Active hub  It has 8 ports and uplink port to cascade another hub.

2. Switch  It is networking device use to connect the different computers of same network ID, it cannot stop broadcasting, it work on layer 2 , it has single broadcast domain and multiple collision domains. It is more intelligent than hub and it is use to connect the different departments. It generally has RAM(to maintain MAC address table) and 24 ports.

There are 2 types of switch :

i)Non-manageable switch   It does not have OS and it is also known as Intelligent hub.

ii) Manageable switch  It have own OS, we can assign IP address and we can create VLAN(Virtual LAN). There are 2 categories for manageable switch :

a)Layer 2 switch  It work on layer 2, it cannot stop broadcasting, it has only one IP address for the entire switch.

b)Layer 3 switch  It work on layer 3 , it can stop broadcasting, each port has own IP address, we can create multiple VLANs, it can perform the routing function but it does not have serial interface or WIC(WAN Interface Card) and Power button.

3. Router   It is more intelligent than switch, it is use to connect the different network ID, it can stop broadcasting, it generally has memory,  OS, WIC, NAT(Network Address Translation) and work on layer 3. It has multiple broadcast domains and multiple collision domains.

4. Gateway  It is more intelligent than router, it can stop broadcasting, it can connect the different network ID and also different protocol stacks(TCP/IP and IPX/SPX).

5. Bridge  It is same as switch but it has only 2 ports.

6. Brouter   It is combination of bridge and router. Some portion use physical address and some portion use logical address for connectivity. It can work on layer 2 and layer 3. It cannot stop broadcasting.

7. Repeater  It can repeat or amplify the signals. It actually send the signals with the same speed as it has received. Maximum 4 repeater can be use in a LAN as per Ethernet standard.

NOTE: MODEM, MUX(Multiplexer), PAD(Packet Assembler De-assembler), Radware, Firewall, NTBackup devices are also use in a network.

OSI Model

It is reference model for networking which helps in planning and troubleshooting of network. It tells that how can data move from source to destination in LAN and WAN.  It is 7 layer model which are actually 7 steps of networking.

There are few things to remember 7 layers (entire networking process) in the sequence like:

All People Seem to Need Data Processing

Please Do Not Throw Sauce Pizza Away

A  P  S   T  N  D  P

Data Encapsulation

Encapsulation means to hide the data or it is wrapping of data. It means to convert data into bits and each bit is securely transferred.

Encapsulation process:

Data -> Segment -> Packet -> Frame -> Bit

NOTE:

De-encapsulation

Convergence time

How toPort Security in Cisco Switch

Port Security in Cisco Switch

Switch# show port-security

# confi  t

# int  f0/20

# switchport mode  access   

# switchport  port-security  <┘

# switchport  port-security   ?

# switchport  port-security

#switchport port-security mac-address ?

#switchport port-security mac-address sticky ?

#switchport port-security mac-address sticky <┘

#switchport port-security ?

#switchport port-security  maximum  ?

#switchport port-security maximum 1  <┘

Switch(config-if)#switchport port-security violation ?

Switch(config-if)#switchport port-security violation shutdown <┘

Switch(config-if)#^Z

Port Security

·         Remembers the Ethernet MAC address connected to the switch port

·         Allows only that MAC address to communicate on that port

·         If any other MAC address tries to communicate through the port, port security will disable the port.

Port Security

·         Shutdown – The default is to shut down the port.

·         Restrict – Alert the network administrator.

·         Protect – Only allow traffic from the secure port and drop packets from other MAC addresses.

Switch>en  <┘

Switch#show version  <┘

Switch#show port-security address <┘

#conf t

#int f0/19

#switchport port-security ?

#switchport port-security   <┘

#switchport mode access <┘

#switchport port-security <┘

#switchport port-security mac-address ?

#switchport port-security mac-address sticky ?

#switchport port-security mac-address sticky   <┘

#switchport port-security ?

#switchport port-security  maximum  ?

#switchport port-security maximum 1  <┘

Switch(config-if)#switchport port-security violation ?

Switch(config-if)#switchport port-security violation shutdown <┘

Switch(config-if)#^Z

Switch#sh port

Switch#sh port-security ?

  address    Show secure address

  interface  Show secure interface

  |          Output modifiers

  <cr>

Switch#sh port-security add

Switch#sh port-security address ?

  <cr>

Switch#sh port-security address

                                                Secure Mac Address Table

-------------------------------------------------------------------------------

Vlan       Mac Address      Type                                      Ports                     Remaining Age

                                                                                                                                (mins)

----         -----------              ----                                         -----                        -------------

------------------------------------------------------------------------------

Total Addresses in System (excluding one mac per port)     : 0

Max Addresses limit in System (excluding one mac per port) : 1024

Switch#

Switch#sh port-security interface f0/19

Port Security              : Disabled

Port Status                : Secure-down

Violation Mode             : Shutdown

Aging Time                 : 0 mins

Aging Type                 : Absolute

SecureStatic Address Aging : Disabled

Maximum MAC Addresses      : 1

Total MAC Addresses        : 0

Configured MAC Addresses   : 0

Sticky MAC Addresses       : 0

Last Source Address:Vlan   : 0000.0000.0000:0

Security Violation Count   : 0

Switch#

Now  Remove computer from port f0/19

Switch#

%LINK-5-CHANGED: Interface FastEthernet0/19, changed state to down

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/19, changed state to down

Attach another computer

Switch#

%LINK-5-CHANGED: Interface FastEthernet0/19, changed state to up

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/19, changed state to up

Then after sometime, it will automatically down

Switch#sh port-security interface f0/19

Port Security              : Disabled

Port Status                : Secure-down

Violation Mode             : Shutdown

Aging Time                 : 0 mins

Aging Type                 : Absolute

SecureStatic Address Aging : Disabled

Maximum MAC Addresses      : 1

Total MAC Addresses        : 0

Configured MAC Addresses   : 0

Sticky MAC Addresses       : 0

Last Source Address:Vlan   : 0000.0000.0000:0

Security Violation Count   : 0

Switch#

#sh port security address

Again connect old pc which is bind previously

Switch#

%LINK-5-CHANGED: Interface FastEthernet0/19, changed state to down

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/19, changed state to down

%LINK-5-CHANGED: Interface FastEthernet0/19, changed state to up

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/19, changed state to up

Switch#show port-security   int f0/19

port status secure Up

To disable port security

Switch#conf t

                #int f0/19

                # no switch port-security   <┘

#^z

# sh port-security f0/19

                (port security Disabled)

# show port –security address  <┘

Switch# clear port-security ?

Switch# clear port-security all  <┘

# sh port-security address <┘

# show mac-address table  <┘