1、Chapter 2 Internetworking Concepts Overview,Objectives,On completion of this chapter, you will be able to perform the following tasks: Describe how data traffic is exchanged between source and destination devices Identify the roles and functions of a hub, switch, and router, and where they best fit
2、in the network Select the appropriate Cisco equipment for a given set of network requirements,Defining Components of the Network,Main Office,Branch Office,Home Office,Mobile Users,Internet,redundency,Floor 2,Floor 1,Server Farm,Defining the Components of a Network (cont.),Branch Office,Telecommuter,
3、ISDN,Remote,Campus,Network Structure Defined by Hierarchy,Distribution Layer,Core Layer,Access Layer,Access Layer Characteristics,End station entry point to the network,Access Layer,Distribution Layer Characteristics,Access Layer Aggregation Point Routes traffic Broadcast/Multicast Domains Media Tra
4、nslation Security Possible point for remote access,Distribution Layer,Core Layer Characteristics,Fast transport to enterprise services No packet manipulation,Core Layer,OSI Model Overview,Data Flow Layers,Transport Layer,Data Link,Network Layer,Physical,注意OSI模型与网络三个层次的区别,Keeping different applicatio
5、ns data separate,User Interface,How data is presented Special processing such as encryption,Transport Layer,Network Layer,Physical,EXAMPLES,Session,Presentation,Application,Role of Application Layers,TCP UDP SPX,802.3 / 802.2 HDLC,EIA/TIA-232 V.35,IP IPX,Presentation,Application,Session,EXAMPLES,Rol
6、e of Data Flow Layers,Reliable or unreliable delivery Error correction before retransmit,Combines bits into bytes and bytes into frames Access to media using MAC address Error detection not correction,Move bits between devices Specifies voltage, wire speed and pin-out cables,Transport,Data Link,Phys
7、ical,Network,Provide logical addressing which routers use for path determination,Encapsulating Data,Transport,Data Link,Physical,Network,Upper Layer Data,Upper Layer Data,TCP Header,Data,IP Header,Data,LLC Header,0101110101001000010,Data,MAC Header,Presentation,Application,Session,Segment,Packet,Bit
8、s,Frame,PDU,Protocol data units,Upper Layer Data,De-encapsulating Data,LLC Hdr + IP + TCP + Upper Layer Data,MAC Header,IP + TCP + Upper Layer Data,LLC Header,TCP+ Upper Layer Data,IP Header,Upper Layer Data,TCP Header,0101110101001000010,Transport,Data Link,Physical,Network,Presentation,Application
9、,Session,Application,Presentation,Session,Transport,Network,Data Link,Physical,OSI Model,PDU,Functional Responsibilities,Examples,Written Exercise: OSI Model,Physical Layer Functions,Defines Media type Connector type Signaling type,Ethernet,802.3,V.35,Physical,EIA/TIA-232,Physical Layer: Ethernet/80
10、2.3,Hub,Hosts,Host,10Base2Thick Ethernet 10Base5Thick Ethernet,10BaseTTwisted Pair,Hubs Operate at Physical layer,A,B,C,D,Physical,All devices in the same collision domain All devices in the same broadcast domain Devices share the same bandwidth,Hubs: One Collision Domain,More end stations means mor
11、e collisions CSMA/CD is used,Data Link layer Functions,Defines Physical source and destination addresses Higher layer protocol (Service Access Point) associated with frame Network topology Frame sequencing Flow control Connection-oriented or connectionless,Data Link,Physical,EIA/TIA-232 v.35,Etherne
12、t,Frame Relay,HDLC,802.2,802.3,Data,Source add,FCS,Length,Dest add,Variable,2,6,6,4,0000.0C xx.xxxx,Vendor assigned,IEEE assigned,MAC Layer - 802.3,Data Link Layer Functions (cont.),Preamble,Ethernet II uses “Type” here and does not use 802.2.,MAC Address,8,# Bytes,Data,Dest SAP,Source SAP,Data,Sour
13、ce add,FCS,Length,Dest add,Variable,1,1,802.2 (SAP),MAC Layer - 802.3,Data Link Layer Functions (cont.),Ctrl,1 or 2,3,2,Preamble,Data,Dest SAP AA,Source SAP AA,Variable,1,1,802.2 (SNAP),Ctrl 03,1 or 2,OR,OUI ID,Type,为高层协议使用,Each segment has its own collision domain All segments are in the same broad
14、cast domain,Data Link,Switches and Bridges Operate at Data Link Layer,OR,1,2,3,1,2,Switches,Each segment has its own collision domain Broadcasts are forwarded to all segments,Memory,Switch,Network Layer Functions,Defines logical source and destination addresses associated with a specific protocol De
15、fines paths through network Interconnects multiple data links,Network,IP, IPX,Data Link,Physical,EIA/TIA-232 v.35,Ethernet,Frame Relay,HDLC,802.2,802.3,Data,Source address,Destination address,IP,Network Layer Functions (cont.),Header,172.15.1.1,Node,Network,Logical Address,Network Layer End Station
16、Packet,Network Layer Functions (cont.),11111111,11111111,00000000,00000000,10101100,00010000,01111010,11001100,Binary Mask,Binary Address,172.16.122.204 255.255.0.0,172,16,122,204,255,Address,Mask,255,0,0,Network,Host,Routing Table,NET,INT,Metric,1,2,4,S0,S0,E0,1,0,0,1.0,4.0,1.3,E0,4.3,S0,2.2,E0,2.1
17、,S0,4.1,4.2,1.1,1.2,Routing Table,NET,INT,Metric,1,2,4,E0,S0,S0,0,0,1,Logical addressing allows for hierarchical network Configuration required Uses configured information to identify paths to networks,Network Layer Functions (cont.),Routers: Operate at the Network Layer,Broadcast control Multicast
18、control Optimal path determination Traffic management Logical addressing Connects to WAN services,Using Routers to Provide Remote Access,Internet,Telecommuter,Branch Office,Modem or ISDN TA,Mobile User,Main Office,Transport Layer Functions,Distinguishes between upper layer applications Establishes e
19、nd-to-end connectivity between applications Defines flow control Provides reliable or unreliable services for data transfer,Network,IPX,IP,Transport,SPX,TCP,UDP,Reliable Transport Layer Functions,Synchronize,Acknowledge, Synchronize,Acknowledge,Data Transfer,(Send Segments),Sender,Receiver,Connectio
20、n Established,Network Device Domains,Hub,Bridge,Switch,Router,Collision Domains:,1 4 4 4,Broadcast Domains:,1 1 1 4,Choosing a Cisco Product,Distribution Layer,Core Layer,Access Layer,Product Selection Considerations,Provides functionality and features you need today Capacity and performance Easy in
21、stallation and centralized management Provides network resiliency Investment protection in existing infrastructure Migration path for change and growth Seamless access for mobile users and branch offices,First select WAN technology solutions based on the following: Availability of service Bandwidth
22、requirement Cost Second, choose products that support selected WAN solutions,Product Selection Considerations (cont.),Cost per Month,Usage,Leased Line, T1,Modem/ISDN,Frame Relay,0,Product Selection Considerations (cont.),1544 128 64 56 19.2 9.6 4.8,Determine applications that you want to run,ISDN, F
23、rame Relay,Old Modem,Telnet,New Modem,Web Browsing,Voice,Video, Multimedia,E-Mail, File Transfer,Leased Line, Frame Relay, XDSL,kbps,Selection Issues:Need for 10 Mbps or 100 Mbps on mediaPort densityNeed for management consoleEasy Operations,Cisco 1500 Micro Hub,Cisco FastHub300,Cisco 1528 Micro Hub
24、 10/100,Cisco FastHub400,Cisco FastHub200,Cisco FastHub100,Cisco Hub Products,Selection Issues: Need for 10 Mbps, 100 Mbps, or 1000 Mbps on media Need for trunking and inter-switch links Workgroup segmentation (VLANs) Port density needs Different user interfaces,Desktop/Workgroup Solutions,Wiring Cl
25、oset/Backbone Solutions,Cisco 1548 Micro Switch 10/100,Catalyst 3000 series,Catalyst 2900 series XL,Catalyst 1900/2820 series,Catalyst 2900 series,Catalyst 5000 series,Catalyst 8500 series,Catalyst Switch Products,Selection Issues:Scale of the routing features neededPort density/variety requirements
26、Capacity and performance Common user interface,Cisco 700/800 Series,Cisco 1600/1700 Series,Cisco 2500 Series,Cisco 3600 Series,AS 5000 Series,Small Office Solutions,Branch Office Solutions,Central Site Solutions,Cisco 12000 GSR Series,Cisco 4000 Series,Cisco 7000 Series,Home Office Solutions,Cisco 2
27、600 Series,Cisco Router Products,Summary,After completing this chapter, you should be able to perform the following tasks: Describe how data moves through a network Identify the roles and functions of routers, switches and hubs, and specify where each device best fits in the network Select the appropriate Cisco equipment for a network that combines switching, routing and remote access requirements,
