Mcts chapter 8

MCTS Guide to Configuring Microsoft Windows Server 2008

Active Directory

Chapter 8: Introduction to Windows Networking

MCTS Windows Server 2008 Active Directory 2

Objectives

2

• Describe networks using Windows terminology

• Configure and troubleshoot TCP/IP protocols

• Describe IPv6 addressing


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


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


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


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


The Network Map (cont.)


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


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


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)


TCP/IP Communication

• When a user opens a web page, a DNS request is sent to resolve the website name to an IP address

• Once the client has the IP address of the website, 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


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 = 11000000.10101000.00000001.00000000255.255.255.0 = 11111111.11111111.11111111.00000000

• Above shows 192.168.1 as the network ID, .0 as the host ID


Assigning IP Address Classes

• Three classes of IP addresses can be assigned: Class A, Class B, or Class C


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


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 “sub-networks”

• Example: 172.31.0.0 subnetted to 255.255.255.0– Creates 256 new networks, with 254 host IDs

– Rule for number of networks = 2n

– Rule for number of hosts = 2n – 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


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


Configuring the Default Gateway

• A default gateway is almost always used in IP configurations

• The default gateway can not 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


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


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


Using the Route Command (cont.)


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


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


The Ipconfig Command

• Ipconfig is usually used to display a computers IP address settings, but it can perform other tasks based on the options given:– /all– /release– /renew– /displaydns– /flushdns– /registerdns


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


The Tracert Command

• Usually called “trace route” because it displays the route 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


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


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


Managing Protocols (cont.)


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 by clicking the up or down arrows in the Adapters and Bindings tab

• Network connections are then prioritized in the order shown under this tab


Network Bindings (cont.)


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


Network Providers (cont.)


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


Internet Protocol Version 6 (cont.)

Dual-stack architecture


Internet Protocol Version 6 (cont.)

Dual-IP layer architecture


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


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


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


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


Subnetting with IPv6 (cont.)

Typical IPV6 address structure


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 multi-step process that often involves the use of several different protocols in the TCP/IP suite


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


Chapter Summary (cont.)

• Several command-line tools are available for checking status and troubleshooting IP configuration, including Ping, Ipconfig, Arp, Tracert, and Nslookup

Technology

Mcts chapter 8