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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Network Security tutorials

  • Network security involves securing the network from external and internal threats. External threats are threats external to the company or network. Internal threats are threats that originate from within the company network and might be inten­tional or unintentional.

  • Network security involves finding a balance between open and evolving networks and protecting company and private data.


Classes of Attacks

  • The following five classes of network attacks exist:

  • Passive: Attacks that include capturing and monitoring unprotected communication and capturing passwords. The attacker gains access to information or data without the consent or knowledge of users.

  • Active: Attacks that actively try to break or bypass security devices, introduce malicious code, and steal and modify data.

  • Close-in: Attacks attempted by an individual in close physical proximity to networks or facilities, with the intent of gathering or changing data.

  • Insider: Attacks that occur from authorized users inside a network. It can be either malicious or non-malicious.

  • Distribution: Attacks that focus on malicious changes to hardware or software at the factory or during distribution to introduce malicious code to unsuspecting users.


Access Attacks

  • Access attacks exploit known web services, databases, operating systems, and authentication services. The five types of access attacks are as follows:

  • Password attacks: Attacks that try to compromise passwords. These include brute-force attacks, Trojan horse programs, IP spoofing, and packet sniffers. Mitigation of these attacks includes disabling accounts after a specific number of unsuccessful login attempts, having complex password requirements, and not using plain-text passwords.

  • Trust exploitation: Attacks that occur when a trusted source on a network takes advantage of its trust. For example, if a trusted system on a network is compromised, it can lead to other systems being compromised on the same network.

  • Port redirection: Attacks that use a compromised host to pass traffic through a firewall that would otherwise be dropped.

  • Man-in-the-middle attacks: Attacks that occur when an attacker, using sniffers, captures and modifies information as it is transmitted from one network to another. These attacks require access to the network media or devices between the source and destination.

  • Buffer overflow: These attacks exploit programming errors that can result in a memory-access exception and program termination or a breach of system security.

  • Application Layer Attacks

  • Application layer attacks try to exploit well-known vulnerabilities and passwords. They have the following characteristics:

  • Exploiting well-known weaknesses in software found on servers such as send mail, HTTP, and FTP to gain elevated access rights to the computer running the software.

  • Trojan horse: programs that monitor login attempts and capture account information. These programs then send the information to the attacker.

  • Password stealing: by prompting the user to enter the system password to gain access to the user's system or accounts.

  • Java and ActiveX: attacks that pass malicious programs to users through a web browser. Application Layer Attacks and Mitigation several ways to mitigate application layer attacks are as follows:


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