Learn Networking

Vtp modes

                                                                                        Vtp modes(vlan)
 Three typews of vtp modes are:-
  Server mode.
  Client mode.
Transparent mode.

Server modes can change and give the permissions to the clients.
    Client mode cann’t change any setting and permission.

  Transparent mode can change all the setting it is work as sever mode it is stand alone mode.

Learn Router Security

Router security

To secure our router:-
To change name of router                                                                            
Configure terminal:-HOSTNAME vardhan                                           
Vardhan(config)#                                                                                            
To enable password telnet:-
Line vty 0 2
Password 123456
Login
Exit
To enable password at console port:-
Line vty 0 (port number)
Password  123456                                                                                                                                     Login
Exit
If we exit or shut down our router it get lost all the securte info so we have to copy it into nv ram by this
Copy running-config startup-config
To reboot router type=reload
To enable password at enable mode:-
Config-t
Enable password 123456
Copy ruunig to starup config
Sh running config:-
Your password is in clear text if u want to convert it or encrypt it
Config-t
Service password-encryption
for more security:-config-t=enable secret 123456  it get more secured.

Learn Networking

Autonomous System

What Is autonomous system is a collection of internet protocol(it).
Asn autonomous system number:-
A unique asn is allocated to each as for use in bgp routing.
The asn uniquely identities each network on the internet.
What is metric:-
Routers use the lowest cost routes to reach a destination and for this work. Metric takes place in routing table for sending packet’s from best path.
Routes have more than one matric.
Rip metric:-
Hop count
Shortest path
Cost
Bandwidth
Lower cost.
BGP metrics:- uses  these protocol to send data by best path.
Weigth
Local preference
Aggregate
As-path legth
Origin type,  etc.
Routing protocols:-

Some routing protocols uses ip address a, b, c,.

Learn Wireless Technology

Wireless Lan

                                                                  WIRELESS LAN
Access point (AP): is a devices which has one interface one antenna and interface for connecting wired connections to wireless.

CHANEEL: a radio frequency band or infrared used for shared communication.
Station (STA):a device or pc which has wireless interface.

Ssid:-service set identifies is a name of of your access point it is of 32 character unique name wireless, network identifier.

Ad hoc: a temporary one made up of stations in mutual range device required wireless device.

Wireless lan: provides network connectivity over wireless media, an AP is installed to act as bridge between wireless and wired network, the AP is need to connected with the wired confection with antennae to provide wireless connectivity.

CSMA/CA:-carrier sense multiple access with collision avoidance(csma/ca).
Before every data transmissions:-
1. Sender sends a requests to send (RTS) frame containing the length of the transmission.
2. receiver respond with a clear to send (CTs) frame.
3. sender sends data
4. receiver sends an (ack) now another sender can sender data.
If sender doesn’t get cts back it assumes collision.

Wireless standards:-
802.11b, 802.11a, 802.11g, 802.11n
Use cross cable to connect pc to ap router
                                                              Wlan security:-
WEP:- is a part of 802.11 standard and uses 64 or 128 bit Rc4 encryption.
WPA:-developed in 2003 because of WEP insecurity.

WPA2.WPA2:-was developed in 2004 because of less security of WPa2.WPa2.