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Learn how to build IP networks, configure Windows Server 2003 as a router, create demand-dial connections, implement VLANs, and more.
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70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network, EnhancedChapter 4: Planning and Configuring Routing and Switching
Objectives • Build IP networks • Configure Windows Server 2003 as a router • Create and configure demand-dial connections • Understand the purpose of virtual LANs • Implement Network Address Translation • Work with Internet Connection Sharing • Configure Internet Connection Firewall • Plan Internet connectivity 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Building a Subnetted IP Network • Subnetting: breaking a single large IP network into smaller networks • Main benefit of subnetting is network traffic control • Supernetting is the opposite process of subnetting • Supernetting combines multiple small networks into one large network 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Binary Numbering and TCP/IP • IP addresses are expressed in dotted decimal notation • A computer looks at an IP address as a single group of 32 binary digits • The subnet mask determines which bits are part of the network ID and which bits are part of the host ID 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Decimal Numbering • The decimal system uses the values from 0 to 9 for each digit • The value of the first column in the decimal numbering system is ten to the zero power (100=1); the value of the second column is ten to the first power (101=10) etc. 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Binary Numbering • Subnetting is based on binary • Binary is a base-two numbering system, which means that there are only two potential values for each digit, 0 and 1 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Conversion Between Binary and Decimal • To convert a binary octet to a decimal value, multiply the digit in each column by the value of each column and then determine the sum of those products • Binary digits are always either 1 or 0, so multiply the value of each column by 1 or 0 • Most people use Windows Calculator to perform the conversion 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Activity 4-1: Converting Binary Numbers to Decimal UsingWindows Calculator • The purpose of this activity is to convert numbers between binary and decimal numbering systems 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Binary Subnet Masks • The binary process used by your computer to find the network ID is called ANDing • If both binary digits being compared have a value of 1, then the result is 1 • If one digit is 0 and the other is 1, or if both digits are zero, then the result is 0 • When an IP address is ANDed with a subnet mask, the result is the network ID 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Activity 4-2: ANDing • The purpose of this activity is to find the network ID of several IP addresses based on the given subnet mask 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
The Benefits of Subnets • Subnetting provides the following benefits: • Improves performance • Reduces collisions • Limits broadcasts • Controls traffic 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Reducing Collisions • Subnetting reduces the number of hosts on each network, reduces the amount of traffic on the network and improves throughput • In a routed network, each network is a separate collision domain • Collisions that occur on one network do not affect another network 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Limiting Broadcasts • Subnetting a network creates multiple networks with fewer hosts on each network • The presence of fewer hosts on each network results in fewer broadcast messages, which reduces the processing load on each host 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Controlling Traffic • Routers provides greater control over network traffic • Routers can implement rules about which packets they forward 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Subnetting a Network • To subnet a network, you take some bits from the host ID and give them to the network ID • The number of subnets can be calculated using the formula 2n-2 • In this formula, n is the number of bits taken from the host ID and used for subnetting • The minus 2 is only used for traditional subnetting in which the subnets of all 1s and all 0s are removed 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Activity 4-3: Complex Subnetting • The purpose of this activity is to subnet a single large network into 10 smaller networks 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Subnet Hosts • The formula 2n-2, is also used to calculate the number of usable hosts on a subnet • The formula finds the total number of combinations that can be created from n bits • However, when used to calculate the number of usable hosts on a subnet, n is the number of bits in the host ID, and two combinations are removed for the broadcast on the subnet and the subnet itself 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Activity 4-4: Finding Valid Hosts • The purpose of this activity is to calculate the number of valid hosts on a subnet 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Supernetting • Supernetting is used to create one large network from several smaller ones • Supernetting takes bits from the network ID and gives them to the host ID • All of the networks being combined for supernetting must be contiguous 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Router Installation and Configuration • Main benefit of implementing Windows Server 2003 as a router within a small or midsized organization is cost • Routing is part of Routing and Remote Access Service (RRAS) and can be configured using the same wizard that is used to configure dial-up and VPN servers 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Router Installation and Configuration (continued) 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Activity 4-5: Configuring RRAS as a Router • The purpose of this activity is to configure Windows Server 2003 as a router 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Routing Tables • The routing table is a list of the networks that are known to the router • Each entry in an IP routing table contains: • the IP address of the network • the subnet mask of the network • the gateway that is used to reach the network • the router interface that is used to reach the gateway • the metric that measures how far away the network is 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Routing Tables (continued) • Static routing is the process by which routing tables are maintained manually by an administrator • Dynamic routing is the process by which routing tables are automatically generated by routers based on communication with other routers 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Routing Protocols • Routing protocols are responsible for calculating the best path from one network to another and advertising routes for dynamic routing • The two routing protocols used in Windows Server 2003 for IP routing are: • Routing Information Protocol (RIP) • Open Shortest Path First (OSPF) 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
RIP • In Routing Information Protocol (RIP), the distance between networks is measured by the number of routers through which the data must pass, or hops • RIP is the simpler and more popular of the two protocols • The best path from one network to another is the path with the least number of hops • This is known as distance-vector routing 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Activity 4-6: Installing and Using RIP • The purpose of this activity is to configure your server as an RIP router 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
OSPF • Open Shortest Path First (OSPF) is a routing algorithm that determines the best path from one network to another based on a configurable value called cost • OSPF is more flexible than RIP and better suited to complex routing environments 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Configuring RIP • In RIP you can configure: • The type of events to be logged • From which IP addresses this router accepts updates • Settings for each interface • How often routing table announcements are sent • How long entries in the routing table last before they expire • Many other options 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Demand-Dial Connections • A demand-dial connection establishes a connection between two routers only when there is data to send • When a router with a demand-dial interface receives packets destined for a remote network, a connection is created so the packets can be sent 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Creating Demand-Dial Connections • For a demand-dial connection to function properly you must: • Enable the server to perform demand-dial routing • Configure a port to allow demand-dial routing • Create a demand-dial interface 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Demand-Dial Interface Wizard • New demand-dial connections are created using the Demand-Dial Interface Wizard • To start this wizard in the Routing and Remote Access snap-in, right-click Network Interfaces, and click New Demand-dial Interface 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Activity 4-7: Creating a Demand-Dial Connection • The purpose of this activity is to create a demand-dial VPN connection 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Demand-dial Interface Properties • Properties of the demand-dial interface can be used to configure security settings and the idle timeout • The idle timeout is on the Options tab • If the Connection type chosen is the Persistent connection option, then the servers are connected whenever RRAS is functional 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Dial-out Hours/Demand-Dial Filters • A demand-dial connection can be configured with a set of dial-out hours that control when it can be active • Controls unwanted dial-up connections that might result in large long-distance charges • Demand-dial filters control which types of network traffic trigger a demand-dial connection • Reduces the number of connections activated and the amount of long-distance charges 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Activity 4-8: Configuring Demand-Dial Filters • The purpose of this activity is to configure demand-dial filters to control the activation of demand-dial connections 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Virtual LANs • A VLAN is a broadcast domain created by a switch based on: • Subnets • Protocols • MAC addresses • switch ports 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Network Address Translation • NAT is a protocol used by routers to allow multiple clients to share a single Internet-addressable IP address • IP headers are modified to make the packet look as though it came from the NAT router 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
How NAT Works • NAT modifies the IP headers of packets that are forwarded through a router • When a packet is forwarded through the router, NAT removes the original source IP address and source port number • The source IP address changes to the IP address of the router • The source port number is changed to a randomly generated port number • To keep track of the translations that are being performed, NAT builds a table 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
How NAT Works (continued) 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
How NAT Works 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Installing NAT • NAT is automatically installed when RRAS is configured to be a router, but interfaces must be added • The NAT/Basic Firewall tab allows you to configure whether this interface is a private interface, public interface, or basic firewall • For proper NAT functionality, one interface must be configured as public and one as private 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Activity 4-9: Installing and Testing NAT • The purpose of this activity is to Install NAT and confirm it is functioning using a Web page on your instructor’s computer 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Configuring NAT • The NAT protocol is configured by right-clicking NAT/Basic Firewall, and clicking Properties 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Internet Connection Sharing • Internet Connection Sharing (ICS) is a Windows Server 2003 service that provides an automated way for a small office using Windows Server 2003 as a router to connect to the Internet • ICS automatically performs NAT and configures network connections 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Internet Connection Firewall • Internet Connection Firewall (ICF) is a stateful packet filter (a filter that automatically creates reverse rules for response traffic) that can be used to protect any server running Windows Server 2003 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Enabling ICF • ICF is configured per connection • ICF is enabled in the properties of a connection • If ICF is enabled on a server that is not a router, only that server is protected • If ICF is enabled on a router, then all computers on the internal network are protected 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Configuring ICF • To allow requests from the network to access services on the server running ICF, you need to configure services • The Security Logging tab, is used to configure: • the type of information that is logged • the location of the log • the maximum size of the log • ICF is capable of logging both dropped packets and successful connections 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Activity 4-10: Installing ICF • The purpose of this activity is to install and configure ICF on your server 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network
Planning Internet Connectivity • When planning Internet Connectivity a decision must be made on whether to use internal private addresses or Internet accessible IP addresses • Using Internet accessible IP addresses is more expensive • Using internal private IP addresses is more secure • Most organizations use internal private IP addresses 70-293: MCSE Guide to Planning a Microsoft Windows Server 2003 Network