1. Cisco Network Support Certifications 2. Networking Terms 3. INTRODUCTION TO NETWORKING 4. TYPES OF NETWORK 5. The Development of the Internet 6. NETWORK ARCHITECTURE 7. TOPOLOGY 8. BUS TOPOLOGY 9. RING TOPOLOGY 10. STAR TOPOLOGY 11. MESH TOPOLOGY 12. HYBRID TOPOLOGY 13. Speed of Networking device 14. NETWORK DEVICES 15. Exploring Wireless Network 16. REPEATERS 17. HUB 18. SWITCH 19. BRIDGE 20. ROUTERS 21. TRANSMISSION Telecommunication 22. Difference between Full Duplex, Half Duplex and Simplex 23. IP-ADDRESSING and IPV4 24. IPv4 address classes 25. IPV6 [ Internet Protocol Version 6 ] 26. SPEED OF VARIOUS DEVICES 27. Network Security 28. Some basic suggestion and steps to prevent Attacks and Network security 29. OSI model 30. UPPER and LOWER Layer 31. Application Layer (Layer 7) 32. Presentation Layer (Layer 6) 33. Session Layer (Layer 5) 34. Transport Layer (Layer 4) 35. Network Layer (Layer 3) 36. Data Link Layer 2 37. Physical Layer 1 38. TCP/IP The DoD Model 39. ROUTED PROTOCOL 40. Ports and Application 41. Important Application, Protocol and Port Number 42. Router Function 43. Types of Routing Protocols 44. STARTING ROUTER 45. CISCO IOS 46. Logging in to the Router 47. CISCO Router IOS commands List 48. Setting time and date of router 49. Router configuration commands 50. Optimizing Switch and Router 51. Understanding Router Terms 52. ROUTER SECURITY 53. Configuring CISCO SWITCH Security Policy 54. IMPLEMENTING STATIC ROUTING 55. UNDERSTANDING THE NEED FOR NAT 56. WAN Connections 57. Access List [ACL] 58. VLAN [Virtual Local Area Network] 59. SPANNING TREE :- BROADCAST STORM 60. Lab 1 Setting up a Serial Interface 61. Lab 2 : IP Addressing 62. Lab 3 Static Routes 63. Lab 4 Default Routes 64. Lab 5 RIP Routes 65. Lab 6 IGRP Routes 66. Lab 7 EIGRP Routes 67. Lab 8 OSPF Routes 68. Lab 9 CHAP and RIP 69. Lab 10 Standard Access-Lists with RIP 70. Lab 11 Extended Access-Lists with RIP 71. Lab 12 Static NAT 72. Lab 13 Many to One NAT 73. Lab 14 NAT Pool 74. Lab 15 ( 2950 Trunk ) 75. Lab 16 ( 2950 Trunk Dynamic ) 76. Lab 17 (2950 VLANs) 77. Lab 18 ( 2950 Deleting VLANs ) 78. Lab 19 ( 2950 VTP ) 79. Lab 20 ( 2950 VTP w/ client ) 80. Lab 21 ( 2950 Telnet )
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WAN Connections tutorials

  • WAN links define a new type of LAYER 1 and LAYER 2 connectivity.

  • It allows links to the internet or other offices

  • Many type of connections are possible with different types and cost



Leases lines

  • It offers dedicated bandwidth between locations. Dedicated means its not shared line. If you are not using your line, no one will be using it

T1 line 1.544 Mbps

E1 line


Circuit Switch

  • on demand bandwidth between location, very low cost, low band width and used by PSTN [Public Switch Telephone Network].

Dial up Modem



Packet Switch

  • It’s a shared bandwidth but guaranteed bandwidth between location.

Frame Relay



  • In CISCO ROUTER you can install a WIC card i.e. Wan Interface Card. It could be

    WIC 1T Old card

    WIC 2T New card that gives you 2 serial connection

    T1 card it is combination of WIC 2T and DSU, so you don’t require

    CSU/DSU old modem

    CSU/DSU it is old expensive modem

    DCE + DTE is Serial Cross over cable that enables us to connect 2 routers

    DCE Data Clocking Equipment

    DTE Data Terminal Equipment


Check Serial controller detail

  • This command will show you DTE/DCE connection, Clock speed for serial interface.

Router# show controllers serial 0/1/0



  • High Level Data Link Control. It is a CISCO proprietor Protocol. It is Layer 2 Protocol and we can use it only if we have all CISCO routers at all the place.


  • Point to Point Protocol. It is industry standard. Used when we have different routers from different manufacturers.


Change encapsulation

  • To change the encapsulation from HDLC to ATM or PPP or SDLC or FRAME-RELAY do as follow

Router# show interface serial 0/1/0 will show encapsulation details

Router# config terminal

Router(config)# interface serial 0/1/0

Router(config-if)# encapsulation ppp


you need to set ppp protocol On both routers to communicate


ppp authentication chap/pap

  • CHAP: Challenge Handshake Authentication Protocol

  • PAP: Password Authentication Protocol is a simple authentication protocol in which the user name and password is sent to the remote access server in a plaintext (unencrypted) form

  • You can verify this by checking from other router by applying


Router2# show ip interface brief

Router2# show interface serial 0/1/0 will show encapsulation details

Router2# config terminal

Router2(config)# interface serial 0/1/0

Router2(config-if)# encapsulation ppp you need to set ppp protocol

  • Now you will be able to communicate with router1 and router.


Cisco devices have ability to move around telnet session. However remember that if you go to connect any device which is not connected in telnet it will hang for 30 seconds. Therefore it is advisable that you first ping telnet device and then connect it using telnet.

Router1# ping ip address of router2

Router1# telnet ip address of router2


“Ctrl + Shift + 6” then “X”

suspend Telnet / SSH session

Exit exit telnet session, to connect you need to give username & password again


Show sessions

shows open session from router


Hit enter or telnet session no

enter key will connect last default session or type session id


Resume “telnet session”

to resume earlier suspended session


Show users

show open session to your router. This may take some time while showing User location, because it search for domain

Name lookup. To disable this feature apply following command.

Router# config terminal

Router(config)# no ip domain-lookup



kills one of your open telnet session


Clear line <x>

Kills an open telnet session


Interpret network diagrams

The best way to look at, build and troubleshoot network diagram is to use CDP. CDP (Cisco Discovery Protocol) is a proprietary protocol designed by CISCO to help administrator collect information about locally & remote attached devices.


Router# sh cdp

gives information about CDP global parameter that can be configured i.e.



is how often CDP packets are transmitted out all active interfaces. Can be configure between 5 to 254 seconds

Router# config terminal

Router(config)# cdp timer ?

Router(config)# cdp timer 90



is amount of time that device will hold packets received from neighbor devices. Can be configured between 10 to 255 seconds

Router# config terminal

Router(config)# cdp holdtime ?

Router(config)# cdp holdtime 120


Router# show cdp neighbors

gives information about directly connected devices. It means that if router is connected to switch, it won’t display devices that are attached to that switch. This gives detail such as Device Id, Local interface, holdtime, capabilities, Platform and Port ID.


Router# show cdp neighbors detail or

Router# show cdp entry *

this command can run both on Router and Switch. It displays detailed information about each device connected to current device


Router# show cdp entry *

protocols this will show you just IP addresses of each directly connected neighbor devices.


Router# show cdp entry *

version this will show you just versions of IOS operating system of your directly connected neighbor devices.

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