Network Technologies. Unit 5, Chapter 8 Switching and Routing. Cisco Learning Institute Network+ Fundamentals and Certification

Transcription

1 Network Technologies Unit 5, Chapter 8 Switching and Routing Cisco Learning Institute Network+ Fundamentals and Certification Copyright 2005 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

2 Binary System This format is called "dotted-decimal notation".

3 Class Leading Bit String Size of Network Number Bit field* Size of Rest Bit field Class A Class B Class C Class D (multicast) Class E (reserved) 1110 not defined not defined 1111 not defined not defined

4 Cla ss Clas s A Clas s B Clas s C Leading Bit String Number of Networks Addresses Per Network ,777, ,384 65, ,097,

5 Class Leading bits Start End CIDR equiva lent Default subnet mask Class A Class B Class C Class D (multicast) Class E (reserved) / / / /4 not defined /4 not defined

6 Hubs Versus Switches: Hubs Broadcast on all Points Hubs broadcast frames received on one port to all other port Switches forward a received frame to a specific port

7 Broadcasts copies of the frame from station A to the other five stations Hubs Versus Switches: Hubs Broadcast on all Points

8 Hubs Versus Switches: Switches Forward Frames to Specific Points Sent from A directly to station F on port 4 Cisco Learning Institute Network+ Fundamentals and Certification Copyright 2005 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

9 Switches use the MAC address for each port to send to the correct port Save port addresses in a lookup table If the MAC address is found in the table, the frame is forwarded to the associated port. If the address is not found, the frame is broadcast to all ports. Once it is accepted further broadcast for that station will not be required.

10 Inside a Switch: Block Diagram of a Switch Input port logic Output port logic Switching fabric Control Bridge

11 Input Port Logic Contains the Ethernet receiving logic and buffer for received frames. Buffering received frams lowers the rate of collisions and allows the switching facric to be busy for short periods of thime without losing data.

12 Output Port Logic Each output port contains and Ethernet transmitter and output frame buffer Buffer required to prevent the switching fabric from stalling Input and output frame buffers allow different speed between ports

13 Responsible for directing the received frames from each input port to the appropriate output port Inside a Switch: Switching Fabrics Crossbar switch is a two dimensional set of data buses. Any combination on I/O connection is possible Multiplexed make one I/O connections at a time. Needs to run faster than individual port speeds

14 Updates and searches the MAC address table Configures the switching fabric Maintains the proper flow control through the switch fabric Inside a Switch: CAM Organization

15 Store and Forward Switching Entire frame is stored as it is received If valid the frame is forwarded to the appropriate output port via the switching fabric Latency delay Cut-Through Switching Reduces the latency As soon as the destination MAC address of the frames is received, the forwarding process begins Errors can be propagated

16 Switches versus Routers Switches are layer 2 (Data-Link) Routers are layer 3 (Network) Use microprocessor-based circuitry to route packets between networks based on their IP address. Switches are used within networks to forward local traffic intelligently. Routers are used between networks to route packets between network in the most efficient manner.

17 Routers Versus Switches Cisco Learning Institute Network+ Fundamentals and Certification Copyright 2005 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

18 Routing Protocols Cisco Learning Institute Network+ Fundamentals and Certification Copyright 2005 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

19 Routing Protocols: Questions to Answer to Figure Out What Routing Protocol to Use Cisco Learning Institute Network+ Fundamentals and Certification Copyright 2005 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

20 Routing Protocols: Ground Rules Cisco Learning Institute Network+ Fundamentals and Certification Copyright 2005 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

21 Routing Protocols: Netstat Cisco Learning Institute Network+ Fundamentals and Certification Copyright 2005 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

22 Routing Protocols: A Router Connecting a Network to the Internet Cisco Learning Institute Network+ Fundamentals and Certification Copyright 2005 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

23 Routing tables Static A number of predefined routes are created and the router lacks the ability to discover new routes. Network administrator needs a detailed knowledge of the network topology and must take the time to manually build and update the routing table as condition change. Dynamic New routes can be discovered or old routes updated as required Maintains routing tables automatically using periodic or ondemand messages through an ongoing communication between routs using he routing protocols. Require little ongoing maintenance and are fault tolerant.

24 Autonomous System Each connected network is part of a larger network called and Autonomous System (AS) An AS is a network or group of networks and router controlled by a single administrative authority An Autonomous System number is associated with each AS Different routing Protocols are used when rouging inside or between an AS

25 Interior Gateway Protocols

26 Interior Gateway Protocols(cont.)

27 Interior and Exterior Gateway Protocols: Interior versus Exterior Gateway Protocols Cisco Learning Institute Network+ Fundamentals and Certification Copyright 2005 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

28 Interior and Exterior Gateway Protocols: RFCs Associated with Routing Protocols Cisco Learning Institute Network+ Fundamentals and Certification Copyright 2005 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

29 Interior and Exterior Gateway Protocols: Exterior Gateway Protocols Cisco Learning Institute Network+ Fundamentals and Certification Copyright 2005 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

30 Classless Inter-Domain Routing Designed to recover many of the unused addresses in class A and class B networks. Know as supernetting Eliminates the concept of classes Written as 4 octets separated by periods and followed by a forward slash a a 2 digit number that represent the length of the subnet masks

31 Classless Inter-Domain Routing: CIDR Address Prefix and Number of Class C Addresses Cisco Learning Institute Network+ Fundamentals and Certification Copyright 2005 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

32 Distance Vector Routing Type of routing algorithm that is base on the number of hops in a route between a source and destination computer Each router send its entire routing table to its neighbor in each update And update is performed every 3- seconds Predecessor to RIP

33 Routing Information Protocol Commonly used distance vector routing protocol Uses the underlying UDP transport Uses a 4-bit metric to count router hops to a destination Can be no larger than 15 hops between the furthest connected station Broadcast every 30 seconds

34 Routing Information Protocol Packets RIP 1 Cisco Learning Institute Network+ Fundamentals and Certification Copyright 2005 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

35 Routing Information Protocol Packets RIP 2 Cisco Learning Institute Network+ Fundamentals and Certification Copyright 2005 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

36 Routing Information Protocol Header Field Information Cisco Learning Institute Network+ Fundamentals and Certification Copyright 2005 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

37 Inter-Gateway Routing Protocol - IGRP Cisco proprietary solution Solves many of the problems associate with the RIP protocol

38 IGRP Properties Cisco Learning Institute Network+ Fundamentals and Certification Copyright 2005 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

39 IGRP Cisco Learning Institute Network+ Fundamentals and Certification Copyright 2005 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

40 Enhanced Inter-Gateway Routing Protocol Develop in the early 90s by Cisco to improve IGRP Only supported by Cisco routers

41 EIGRP Improvements Cisco Learning Institute Network+ Fundamentals and Certification Copyright 2005 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

42 Link State Routing Link stat routing algorithm broadcasts information about the cost of reach each of its neighbors to all other routers in the network. Creates a consistent view of the network at each router A path with the least hops may not be chosen as the leas cost route

43 Link State Routing: Routing Based on Weighted Connections Cisco Learning Institute Network+ Fundamentals and Certification Copyright 2005 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

44 Link State Routing: Link State Router Characteristics Cisco Learning Institute Network+ Fundamentals and Certification Copyright 2005 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

45 To reduce the amount of multicast router traffic on a network an spanning tree is used to create non-looping paths between the router in the network Link State Routing: Choosing the Best Route Between Nodes Using a Spanning Tree Cisco Learning Institute Network+ Fundamentals and Certification Copyright 2005 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

46 Link State Routing: Link State Header Fields Cisco Learning Institute Network+ Fundamentals and Certification Copyright 2005 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

47 Link State Routing: Link State Header Field Information Cisco Learning Institute Network+ Fundamentals and Certification Copyright 2005 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

48 ES-IS an OSI protocol that define show end systems and intermediate systems learn about each other process in know as oconfiguation Happens before touting between endsysstems can occur Once configured data can be exchande between the end system and intermediate sysstems and vice-versa.

49 IS-IS An OSI link state hierarchical routing protocol that floods the network with link state information to build a complete consistent picture of network topology

50 IS-IS, Integrated IS-IS, NSLP, and BGP: IS-IS Packet Header Cisco Learning Institute Network+ Fundamentals and Certification Copyright 2005 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

51 IS-IS, Integrated IS-IS, NSLP, and BGP: IS-IS Field Header Information Cisco Learning Institute Network+ Fundamentals and Certification Copyright 2005 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

52 Integrated IS-IS Routing protocol based on the OSI routing protocol but also supports IP and other protocols. Send only one set of routing update, making it more efficient

53 Netware Link Services Protocol Used to route IP packets in a Novell network (based on IS-IS routing)

54 NLSP Benefits Cisco Learning Institute Network+ Fundamentals and Certification Copyright 2005 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

55 Inter-Domain Routing Protocol (IDRP) An OSI protocol that specifies how router communicate with router in different domain. Based on Border Gateway Protocol

56 Protocol for exchanging routing information between two neighbor gateway hosts in a network of autonomous systems EGP

57 BGP Provides loop-free inter-domain touting between ASs. Can be used for both internal and external routing Used the TCP transport protocol (port 179) Chooses the single best path for reaching a destination

58 BGP Header Fields Cisco Learning Institute Network+ Fundamentals and Certification Copyright 2005 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

59 BGP Header Fields Cisco Learning Institute Network+ Fundamentals and Certification Copyright 2005 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

60 Policy Routing Any type of routing that is based on factors other than the selection of the shortest Path Contract obligations Quality of service Service provider selection

61 Multi-Protocol Label Switching MPLS allow for faster, cheaper IP router based on ATM technology. Labels are short than IP address, the packet can be forwarded at a faster rate. Give network administrator a great deal of flexibility to divert and route traffic around link failures, congestion and bottlenecks

62 PINNI ATM Forum specification for the protocols between switches in a private ATM network Includes a routing protocol for reliable distributing network topology information so that paths can be computed to any addressed destination. Includes a signaling protocol for the establishment and takedown of PTP and point-to-multipoint connections.

63 Layer 3 Switching: Benefits Switch and router in one package Cisco Learning Institute Network+ Fundamentals and Certification Copyright 2005 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

64 ISP Diagram: Overhead View of ISP Network Hardware Cisco Learning Institute Network+ Fundamentals and Certification Copyright 2005 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved.

65 Troubleshooting Techniques