1. MCTS Guide to Configuring Microsoft Windows Server 2008 Active Directory Chapter 8: Introduction to Windows Networking

2. MCTS Windows Server 2008 Active Directory2 Objectives 2 Describe networks using Windows terminology Configure and troubleshoot TCP/IP protocols Describe IPv6 addressing

3. MCTS Windows Server 2008 Active Directory3 Windows Networking Terminology Network media Network interface card (NIC) NIC driver Hub or switch Router Network protocol Client Service Network Internetwork Network connection Network discovery

4. MCTS Windows Server 2008 Active Directory4 The Network and Sharing Center Can create network connections, view the status of existing connections, and troubleshoot network problems Additionally, you can enable and disable the discovery of other computers on the network and configure folder sharing Three sections –The network map –Sharing and Discovery –Tasks

5. MCTS Windows Server 2008 Active Directory5 The Network Map The network map displays a graphical view of the network from your computer’s perspective Upon connection to a network, Windows asks you to select the type of network you are connecting to: Home, Work, or Public Based on this choice, Windows designates your network as one of the following types: –Public –Private –Domain

6. MCTS Windows Server 2008 Active Directory6 The Network Map (cont.) Devices that run Windows Server 2003 or Windows XP can’t be placed on the map because they lack the necessary Link Layer Topology Discovery (LLTD) protocol Other reasons that a device can’t be placed –A computer running Vista connected to a network designated as public –LLTD is disabled –Network discovery is turned off –Firewall settings on the computer or network are preventing Windows from detecting the computer –The NIC drivers don’t support LLTD

7. MCTS Windows Server 2008 Active Directory7 The Network Map (cont.)

8. MCTS Windows Server 2008 Active Directory8 The Sharing and Discovery Section You can enable and disable the following functions in the Sharing and Discovery section: –Network discovery –File sharing –Public folder sharing –Printer sharing This section can also display information about what’s currently being shared on the computer

9. MCTS Windows Server 2008 Active Directory9 The Tasks Section The Tasks section has links to perform the following tasks: –View computers and devices –Connect to a network –Set up a connection or network –Manage network connections –Diagnose and repair

10. MCTS Windows Server 2008 Active Directory10 TCP/IP Operation and Configuration TCP/IP is the default network protocol installed on Windows computers; Windows Server 2008 and Vista are the first two to have IPv4 and IPv6 installed by default TCP/IP is a suite of protocols –Domain Name System (DNS) –Dynamic Host Configuration Protocol (DHCP) –Transmission Control Protocol (TCP) –User Datagram Protocol (UDP) –Internet Protocol version 4 (IPv4) –Internet Control Message Protocol (ICMP) –Address Resolution Protocol (ARP)

11. MCTS Windows Server 2008 Active Directory11 TCP/IP Communication When a user opens a Web page, a DNS request is sent to resolve the Web site name to an IP address Once the client has the IP address of the Web site, it then determines whether the address is on the same network or a different network If the client is on the same network, the client requests the MAC address of the Web server; if not, the client sends the request for the Web page to a router or default gateway Routers then forward the request to other routers until the request reaches a router connected to the Web server’s network

12. MCTS Windows Server 2008 Active Directory12 IPv4 Address Configuration IP addresses are 32-bit numbers divided into four 8-bit values called octets; each octet can have a value from 0 to 255 Subnet masks are also 32-bit numbers that serve to determine how many bits are allocated to a network ID and how many are allocated to a host ID When written in binary, 1’s in the subnet mask that correspond to bits in the IP address mean the matching bit locations are part of the network ID 192.168.1.0 = 11000000.10101000.00000001.00000000 255.255.255.0 = 11111111.11111111.11111111.00000000 Above shows 192.168.1 as the network ID,.0 as the host ID

13. MCTS Windows Server 2008 Active Directory13 Assigning IP Address Classes Three classes of IP addresses can be assigned: Class A, Class B, or Class C

14. MCTS Windows Server 2008 Active Directory14 IP Address Assignment Rules Rules for IP address assignment –Every IP address configuration must have a subnet mask –All hosts on the same physical network must share the same network ID in their IP addresses –All host IDs on the same network must be unique –You can’t assign an IP address in which all the host ID bits are binary 0 –You can’t assign an IP address in which all the host ID bits are binary 1 –Computers assigned different network IDs can communicate only if a router is present to forward packets

15. MCTS Windows Server 2008 Active Directory15 Subnetting Default subnet mask for an address class does not always apply Bits can be borrowed from the host ID portion of an address class in order to create additional “subnetworks” Example: 172.31.0.0 subnetted to 255.255.255.0 –Creates 256 new networks, with 254 host IDs –Rule for number of networks = 2 n –Rule for number of hosts = 2 n – 2 An IP network is referred to as a broadcast domain Creating multiple subnets can be beneficial in large environments to reduce the amount of traffic (broadcast traffic specifically) computers are exposed to

16. MCTS Windows Server 2008 Active Directory16 Configuring Multiple IP Addresses Windows OSs allow assigning multiple IP addresses to a single network connection, via Advanced TCP/IP settings dialog box Multiple IP addresses can be useful in these situations: –The computer is hosting a service that must be accessed by using different addresses –The computer is connected to a physical network that hosts multiple IP networks

17. MCTS Windows Server 2008 Active Directory17 Configuring the Default Gateway A default gateway is almost always used in IP configurations The default gateway cannot be in a network ID outside of the host’s network ID Just as you can configure multiple IP addresses, multiple gateways can be configured Windows attempts to select the gateway with the best metric automatically Metric is a value assigned to the gateway based on the speed of the interface used to access the gateway

18. MCTS Windows Server 2008 Active Directory18 Using Multihomed Servers A multihomed server has two or more NICs, each attached to a different IP network Each NIC requires its own IP address for the network to which it’s connected Reasons for this type of configuration –A server is accessed by internal clients and external clients –A server provides resources for computers on multiple subnets of the network –A server is configured as a router or VPN server Multihomed servers can run into routing issues due to multiple default gateways being configured

19. MCTS Windows Server 2008 Active Directory19 Using the Route Command Windows computers maintain a routing table that dictates where a packet should be sent, based on the packet’s destination address Typing route print displays the routing table Results are displayed in five columns –Network Destination –Netmask –Gateway –Interface –Metric Route command can be used to change the routing table and to fix issues caused by using a multihomed server

20. MCTS Windows Server 2008 Active Directory20 Using the Route Command (cont.)

21. MCTS Windows Server 2008 Active Directory21 IP Configuration Command-Line Tools Other command-line tools available to assist with IP configuration –Ping –Ipconfig –Arp –Tracert –Nslookup Additional tools are available but are generally used to verify correct IP configuration settings and connectivity

22. MCTS Windows Server 2008 Active Directory22 The Ping Command Ping is used to test the connectivity between two computers by sending an ICMP Echo Request packet If the destination receives the ICMP Echo Request and can respond, it’ll reply with an ICMP Echo Reply packet –Example: Reply from 192.168.100.201 bytes=32 time=<1ms TTL=128 To see the options available for the ping command, type ping /? at the command prompt

23. MCTS Windows Server 2008 Active Directory23 The Ipconfig Command Ipconfig is usually used to display a computer’s IP address settings, but it can perform other tasks based on the options given –/all –/release –/renew –/displaydns –/flushdns –/registerdns

24. MCTS Windows Server 2008 Active Directory24 The Arp Command The Arp command displays or makes changes to the Address Resolution Protocol (ARP) cache, which contains IP address – MAC address pairs Can add static ARP entries Some options for ARP command –-a, -g: displays current ARP entries –-d: deletes ARP entries –-s: adds a static ARP entry

25. MCTS Windows Server 2008 Active Directory25 The Tracert Command Usually called “trace route” because it displays the route that packets take between two computers Works by sending out packets with a TTL value starting at 1 and increases the value until the destination is reached Useful for troubleshooting the routing topology of a complex network and finding bottlenecks

26. MCTS Windows Server 2008 Active Directory26 The Nslookup Command Used to test and troubleshoot DNS operation Can be used in command mode or interactive mode In command mode, you type “nslookup host” to query for the host’s address In interactive mode, you can simply type host to get the host’s address Typing a question mark at the interactive mode prompt gives a list of available options

27. MCTS Windows Server 2008 Active Directory27 Managing Protocols Each network connection in Windows Server 2008 has protocols and services associated with it Services / protocols can be unbound (disabled) or bound (enabled) to a connection in the connection’s Properties dialog box by selecting or deselecting the check box next to the service or protocol List of services / protocols –Client for Microsoft Networks –QoS Packet Scheduler –File and Printer Sharing for Microsoft Networks –Internet Protocol Version 6 (TCP/IPv6) –Internet Protocol Version 4 (TCP/IPv4) –Link-Layer Topology Discovery Mapper I/O Driver –Link-Layer Topology Discovery Responder

28. MCTS Windows Server 2008 Active Directory28 Managing Protocols (cont.)

29. MCTS Windows Server 2008 Active Directory29 Network Bindings By default, every installed service and protocol is bound to every network connection Protocol bindings can be rearranged by selecting the protocol to be moved and then clicking the up or down arrows in the Adapters and Bindings tab Network connections are then prioritized in the order shown under this tab

30. MCTS Windows Server 2008 Active Directory30 Network Bindings (cont.)

31. MCTS Windows Server 2008 Active Directory31 Network Providers A network provider is a software component that allows Windows applications to connect to resources on other computers Different OSs may require different procedures, which requires different network providers Network providers exist for Windows networks, virtual networks (VMware), Novell networks, Linux networks, and more Performs actions such as making and breaking network connections

32. MCTS Windows Server 2008 Active Directory32 Network Providers (cont.)

33. MCTS Windows Server 2008 Active Directory33 Internet Protocol Version 6 Previous Windows OSs use a dual-stack architecture, meaning that IPv4 and IPv6 use separate implementations of the protocols in the TCP/IP suite Windows Server 2008 and Vista use dual-IP layer architecture, which means that the IP protocol is the only component of the TCP/IP suite that’s different in IPv6

34. MCTS Windows Server 2008 Active Directory34 Internet Protocol Version 6 (cont.) Dual-stack architecture

35. MCTS Windows Server 2008 Active Directory35 Internet Protocol Version 6 (cont.) Dual-IP layer architecture

36. MCTS Windows Server 2008 Active Directory36 IPv6 Overview Originally named IPng (IP next generation), IPv6 was created in 1994 by the Internet Engineering Task Force (IETF) IPv6 includes the following improvements: –Large address space –Hierarchical address space –Autoconfiguration –Built-in Quality of Server (QoS) support –Built-in security

37. MCTS Windows Server 2008 Active Directory37 IPv6 Address Structure Subnetting as done in IPv4 is no longer applicable Uses 128 bits, instead of IPv4’s 32 bits, for an address IPv6 addresses are written as eight 16-bit hexadecimal numbers separated by colons –Fe80:0:0:0:18ff:0024:8e5a:60 –Things to note about IPv6 addresses One or more consecutive 0 values can be written as a double colon, but only one double colon can exist in an IPv6 address Leading 0s are optional Addresses that start with fe80 are called link-local addresses and are self-configuring

38. MCTS Windows Server 2008 Active Directory38 The IPv6 Host ID Host ID of an IPv6 is typically 64 bits and uses the interface’s 48-bit MAC address for a large portion of the address, as well as a 16-bit value of FF-FE that is inserted after the first 24 bits of the MAC address First two zeros in a MAC address are replaced with 02 This autoconfigured 64-bit host ID is referred to as an Extended Unique Identifier (EUI)-64 interface ID Windows Server 2008 and Vista don’t use EUI-64 by default

39. MCTS Windows Server 2008 Active Directory39 Subnetting with IPv6 Subnetting will still exist in IPv6, but due to the large address space available, most address allocations will have a /48 prefix This leaves 80 bits for assigning subnets and host IDs 80 bits allows 16 subnet bits (since the interface ID requires 64 bits), allowing up to 65,536 subnets

40. MCTS Windows Server 2008 Active Directory40 Subnetting with IPv6 (cont.) Typical IPV6 address structure

41. MCTS Windows Server 2008 Active Directory41 Chapter Summary The Network and Sharing Center can view the status of network connections and configure their properties The network map is a visual representation of computers and connecting devices in your network TCP/IPv4, the predominant networking protocol in use today, is actually a suite of protocols and services, such as DNS, DHCP, TCP, IPv4, ICMP, and ARP, among others TCP/IP communication is a multistep process that often involves the use of several different protocols in the TCP/IP suite

42. MCTS Windows Server 2008 Active Directory42 Chapter Summary (cont.) An IP address is a 32-bit dotted decimal number divided into four octets Every IP address must have a subnet mask to indicate which part of the address is the network ID and which part is the host ID; three IP classes exist: A, B, C Subnetting uses a modified subnet mask to divide a large network into smaller, more manageable networks You can configure multiple IP addresses and default gateways on a network connection

43. MCTS Windows Server 2008 Active Directory43 Chapter Summary (cont.) Several command-line tools are available for checking status and troubleshooting IP configuration, including Ping, Ipconfig, Arp, Tracert, and Nslookup