OSI Network Layer
Upcoming SlideShare
Loading in...5
×

Like this? Share it with your network

Share

OSI Network Layer

  • 414 views
Uploaded on

OSI Network Layer

OSI Network Layer

More in: Technology
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Be the first to comment
    Be the first to like this
No Downloads

Views

Total Views
414
On Slideshare
414
From Embeds
0
Number of Embeds
0

Actions

Shares
Downloads
25
Comments
0
Likes
0

Embeds 0

No embeds

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
    No notes for slide

Transcript

  • 1. OSI Network Layer Network Fundamentals – Chapter 5 ITE I Chapter 6 © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 1
  • 2. Objectives  Identify the role of the Network Layer, as it describes communication from one end device to another end device  Identify the most common Network Layer protocol, Internet Protocol (IP), and its features for providing connectionless and best-effort service  Identify the principles used to guide the division or grouping of devices into networks  Identify the hierarchical addressing of devices and how this allows communication between networks  Identify the fundamentals of routes, next hop addresses and packet forwarding to a destination network ITE 1 Chapter 6 © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 2
  • 3. Network Layer Protocols and Internet Protocol (IP)  Provides addressing via IP version 4 and increasingly IPv6  The routing of data ITE 1 Chapter 6 © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 3
  • 4. Network Layer Protocols and Internet Protocol (IP)  Internet Protocol version 4 (IPv4)  Allows network devices to find each other ITE 1 Chapter 6 © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 4
  • 5. Network Layer Protocols and Internet Protocol (IP)  IP protocol is connectionless  The receiver is not contacted before the data is sent ITE 1 Chapter 6 © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 5
  • 6. Network Layer Protocols and Internet Protocol (IP)  IP is an unreliable protocol i.e. does not guarantee data delivery ITE 1 Chapter 6 © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 6
  • 7. Network Layer Protocols and Internet Protocol (IP)  IP uses the same protocol irrespective of the media ITE 1 Chapter 6 © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 7
  • 8. Network Layer Protocols and Internet Protocol (IP)  Transport Layer Segments or PDU are encapsulated in Packets ITE 1 Chapter 6 © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 8
  • 9. Network Layer Protocols and Internet Protocol (IP)  IP Packets have fields just like TCP/UDP segments  IP Encapsulate TCP/UDP segment with its header Ver = IPv4 IHL = IP header length, Service Type =Priority (QOS), Header Checksum = Error checking Source Address =IP address of data source Destination address = Data destination address ITE 1 Chapter 6 © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 9
  • 10. Hierarchical Addressing scheme (IP) and grouping networks  Enhances: Security, Manageability, Performance, Troubleshooting, Scalability Networks can be Divided on: Department Purpose Location User – Permissions User – Rights ITE 1 Chapter 6 © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 10
  • 11. Hierarchical Addressing aids performance  Performance: Keeping traffic where it should be increases network performance Broadcast = The ability to reach all the devices on your network with the same data ITE 1 Chapter 6 © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 11
  • 12. Hierarchical Addressing improves security  Security: User permission and rights can be specified ITE 1 Chapter 6 © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 12
  • 13. Hierarchical Addressing aids data delivery  Structure allows network devices to be quickly found i.e. What network, then what host on that network ITE 1 Chapter 6 © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 13
  • 14. Networks and their address can be subdivided with subnetting  The host portion can be further subdivided into smaller networks or subnets Subnetting converts Host bits into Network bits ITE 1 Chapter 6 © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 14
  • 15. Fundamentals of Routes, Next Hop Addresses and Packet Forwarding  Routers allow devices on different networks to pass data between each other ITE 1 Chapter 6 © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 15
  • 16. Fundamentals of Routes, Next Hop Addresses and Packet Forwarding  To move packets to a different network a router is required ITE 1 Chapter 6 © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 16
  • 17. Fundamentals of Routes, Next Hop Addresses and Packet Forwarding  Gateways are used to pass data to other networks ITE 1 Chapter 6 © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 17
  • 18. Gateways  Gateways lead to other networks ITE 1 Chapter 6 © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 18
  • 19. Fundamentals of Routes, Next Hop Addresses and Packet Forwarding  A route consist of: Destination network, a Next hop interface address and an Outgoing interface ITE 1 Chapter 6 © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 19
  • 20. Fundamentals of Routes, Next Hop Addresses and Packet Forwarding  A destination network is where the data is required to be when its journey is complete ITE 1 Chapter 6 © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 20
  • 21. Fundamentals of Routes, Next Hop Addresses and Packet Forwarding  The next hop interface address tells the current router what next interface to use for data to reach its destination network ITE 1 Chapter 6 © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 21
  • 22. Fundamentals of Routes, Next Hop Addresses and Packet Forwarding  Routers move packet between subnets ITE 1 Chapter 6 © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 22
  • 23. Fundamentals of Routes, Next Hop Addresses and Packet Forwarding  Routing protocols allow routers to learn routing tables that contain the location of networks  Routing tables can be statically (manually) or dynamically (automatically) configured ITE 1 Chapter 6 © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 23
  • 24. Fundamentals of Routes, Next Hop Addresses and Packet Forwarding  Routes or destination networks can be configured to automatically build routing tables i.e. (RIP,IGRP,EIGRP,OSPF etc) ITE 1 Chapter 6 © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 24
  • 25. Testing network addresses and connectivity  Both ping and tracert are used by network engineers to test network connectivity. For basic network connectivity, the ping command works best. To test latency (delay) and the network path, the tracert command is preferred.  The ability to accurately and quickly diagnose network connectivity issues is a skill expected from network engineer. Knowledge about the TCP/IP protocols and practice with troubleshooting commands will build that skill. ITE 1 Chapter 6 © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 25
  • 26. Ping example ITE 1 Chapter 6 © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 26
  • 27. Tracert example ITE 1 Chapter 6 © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 27
  • 28. Labs  Lab 5.5.2 Examining a route (Destination networks, Next hop interface, Gateway)  Lab 6.7.1- Ping and Traceroute (Testing connectivity) ITE 1 Chapter 6 © 2006 Cisco Systems, Inc. All rights reserved. Cisco Public 28