11 ROUTING IP Chapter 3

Chapter 3: ROUTING IP2 CHAPTER INTRODUCTION  Understand the function of a router.  Understand the structure of a routing table.  Choose between static or dynamic routing on your network.  Select, install, and configure the dynamic routing protocol most suitable for your network.  Use routers to connect LANs and WANs.  Understand the function of a router.  Understand the structure of a routing table.  Choose between static or dynamic routing on your network.  Select, install, and configure the dynamic routing protocol most suitable for your network.  Use routers to connect LANs and WANs.

Chapter 3: ROUTING IP3 UNDERSTANDING IP ROUTING  Routers direct data through the network.  Routers connect two networks or two segments on an internetwork.  Routers can be used on LANs to provide connectivity between segments, on WANs to provide connectivity between LANs, and on either to provide connectivity to the Internet.  Routers direct data through the network.  Routers connect two networks or two segments on an internetwork.  Routers can be used on LANs to provide connectivity between segments, on WANs to provide connectivity between LANs, and on either to provide connectivity to the Internet.

Chapter 3: ROUTING IP4 ROUTER FUNCTIONS  Has a minimum of two network interfaces  Holds a table of network information that it uses to make routing decisions  Can be either a hardware device or a software application  Has a minimum of two network interfaces  Holds a table of network information that it uses to make routing decisions  Can be either a hardware device or a software application

Chapter 3: ROUTING IP5 ROUTING LAN TRAFFIC

Chapter 3: ROUTING IP6 WAN ROUTING

Chapter 3: ROUTING IP7 CHOOSING A WAN TOPOLOGY  Mesh  Ring  Star  Mesh  Ring  Star

Chapter 3: ROUTING IP8 MESH TOPOLOGY

Chapter 3: ROUTING IP9 RING TOPOLOGY

Chapter 3: ROUTING IP10 STAR TOPOLOGY

Chapter 3: ROUTING IP11 SELECTING A WAN TECHNOLOGY  Leased Lines  More expensive than dial on demand  Guaranteed always-on service  Dial on Demand  Generally less expensive  Pay for what you use  Leased Lines  More expensive than dial on demand  Guaranteed always-on service  Dial on Demand  Generally less expensive  Pay for what you use

Chapter 3: ROUTING IP12 USING LEASED LINES  Permanent, always-on connection  Expensive to install and run  Can only be used to connect to a specified location  Normally provided as a managed service by a communications company  Permanent, always-on connection  Expensive to install and run  Can only be used to connect to a specified location  Normally provided as a managed service by a communications company

Chapter 3: ROUTING IP13 USING DIAL-ON-DEMAND CONNECTIONS  Includes ISDN, modem  Links only used when necessary  Normally charged on a usage basis  Less expensive than leased-line installations  Can be used to connect to more than one location  Includes ISDN, modem  Links only used when necessary  Normally charged on a usage basis  Less expensive than leased-line installations  Can be used to connect to more than one location

Chapter 3: ROUTING IP14 USING FRAME RELAY

Chapter 3: ROUTING IP15 USING VIRTUAL PRIVATE NETWORKS

Chapter 3: ROUTING IP16 ROUTING IP MULTICAST TRAFFIC

Chapter 3: ROUTING IP17 USING NETWORK SWITCHES

Chapter 3: ROUTING IP18 SWITCHES, ROUTERS, AND PERFORMANCE  Switches are more expensive than hubs.  Switches are less expensive than routers.  Switches provide excellent performance improvements over hub-based networks.  Switches are more expensive than hubs.  Switches are less expensive than routers.  Switches provide excellent performance improvements over hub-based networks.

Chapter 3: ROUTING IP19 COMBINING ROUTING AND SWITCHING  A switch reduces collisions but does not create a broadcast domain.  Implementation of VLANs allows creation of broadcast domains.  Ability to create a VLAN depends on the switch.  A switch reduces collisions but does not create a broadcast domain.  Implementation of VLANs allows creation of broadcast domains.  Ability to create a VLAN depends on the switch.

Chapter 3: ROUTING IP20 SELECTING ROUTERS AND SWITCHES  Software based  Places processing overhead on host server  Allows functionality to be added or removed easily  Hardware based  Generally faster and more reliable than software based routers  More difficult to add or remove features  Software based  Places processing overhead on host server  Allows functionality to be added or removed easily  Hardware based  Generally faster and more reliable than software based routers  More difficult to add or remove features

Chapter 3: ROUTING IP21 UNDERSTANDING ROUTING TABLES  The routing table contains a listing for each route including:  Network Address  NetMask  Gateway Address  Interface  Metric  The routing table contains a listing for each route including:  Network Address  NetMask  Gateway Address  Interface  Metric

Chapter 3: ROUTING IP22 STATIC VERSUS DYNAMIC ROUTING Static routing  An administrator manually enters information into the routing table, using a program designed for that purpose. Dynamic routing  The router receives routing table information automatically from other routers, using a specialized routing protocol. Static routing  An administrator manually enters information into the routing table, using a program designed for that purpose. Dynamic routing  The router receives routing table information automatically from other routers, using a specialized routing protocol.

Chapter 3: ROUTING IP23 USING STATIC ROUTING  Requires routes to be configured manually  Route.exe command line utility  Routing and Remote Access MMC snap-in  Requires routes to be configured manually  Route.exe command line utility  Routing and Remote Access MMC snap-in

Chapter 3: ROUTING IP24 USING DYNAMIC ROUTING  Specialized routing protocols communicate information between routers.  Self-maintaining.  Requires no intervention in the event of a topology change.  Specialized routing protocols communicate information between routers.  Self-maintaining.  Requires no intervention in the event of a topology change.

Chapter 3: ROUTING IP25 SELECTING A ROUTING PROTOCOL  Distance vector routing protocols  Less administration  Better suited to smaller networks  Link state routing protocols  Require more administration  More effective in larger networks  Distance vector routing protocols  Less administration  Better suited to smaller networks  Link state routing protocols  Require more administration  More effective in larger networks

Chapter 3: ROUTING IP26 DISTANCE VECTOR ROUTING  Uses simple hop count to determine route to take across the network  1 router = 1 hop  Doesn’t necessarily indicate the best or fastest route  Uses simple hop count to determine route to take across the network  1 router = 1 hop  Doesn’t necessarily indicate the best or fastest route

Chapter 3: ROUTING IP27 LINK STATE ROUTING  Uses complex algorithms to determine preferred route  The number of hops between the router and the destination  The transmission speed of the links connecting the router to the destination  Delays caused by network traffic congestion  A route cost value, supplied by an administrator  Uses complex algorithms to determine preferred route  The number of hops between the router and the destination  The transmission speed of the links connecting the router to the destination  Delays caused by network traffic congestion  A route cost value, supplied by an administrator

Chapter 3: ROUTING IP28 UNDERSTANDING ROUTING PROTOCOL COMMUNICATIONS  Distance vector  Each router transmits information about every router it knows about to every other router on the network.  Information is retransmitted periodically irrespective of any change in the network topology.  Link state  After initial discovery, only changes are transmitted.  Information is only transmitted to neighboring routers.  Distance vector  Each router transmits information about every router it knows about to every other router on the network.  Information is retransmitted periodically irrespective of any change in the network topology.  Link state  After initial discovery, only changes are transmitted.  Information is only transmitted to neighboring routers.

Chapter 3: ROUTING IP29 ADMINISTERING ROUTING PROTOCOLS  Distance vector  Minimal configuration  Minimal ongoing administration  Link state  Potentially complex configuration  Minimal ongoing administration  Distance vector  Minimal configuration  Minimal ongoing administration  Link state  Potentially complex configuration  Minimal ongoing administration

Chapter 3: ROUTING IP30 USING ROUTING AND REMOTE ACCESS  RRAS  Service in Windows 2003  Configured via the Routing and Remote Access MMC snap-in  RRAS  Service in Windows 2003  Configured via the Routing and Remote Access MMC snap-in

Chapter 3: ROUTING IP31 CHAPTER SUMMARY  Routers enable communication between networks.  Routers can take the form of software or hardware.  A WAN topology defines the pattern of connections among your network sites.  Multicasting allows you to send data to a group of machines using a single IP address.  Routers enable communication between networks.  Routers can take the form of software or hardware.  A WAN topology defines the pattern of connections among your network sites.  Multicasting allows you to send data to a group of machines using a single IP address.

Chapter 3: ROUTING IP32 CHAPTER SUMMARY (continued)  Static routing describes the manual creation of routing table entries.  Dynamic routing uses specialized routing protocols to update changes in the network topology.  RRAS can be used on Windows Server 2003 systems to configure static and dynamic routing.  Static routing describes the manual creation of routing table entries.  Dynamic routing uses specialized routing protocols to update changes in the network topology.  RRAS can be used on Windows Server 2003 systems to configure static and dynamic routing.