Introduction to Networking Concepts

Introducing TCP/IP AddressingNetwork address – common portion of the IP

address shared by all hosts on a subnet/network.

Host address – the part of the IP address the uniquely identifies each host on a network

The Network and Host parts of the address are determined by the subnet mask.

Default Gateway – a way out of our network. Allows us to communicate outside the LAN.

IPv4 vs IPv6IPv4 uses a 32 bit address and subnet mask –

sometimes broken down into legacy “classes of networks” (page 4)

IPv4 addresses are running out – techniques such as Private IP addresses are being used along with NAT to help save some addresses. (page 5)

IPv6 uses 128 bit. Provides up to 2^128 unique addresses. 20AB:0db8:85d3:1218:8a2e:0370:7334 is an exaple of an IPv6 address

IPv6 address use a 48 bit subnet mask.

Introduction to DNSDNS – provides a mechanism for associating

meaninful host names with network address. It is easier to remember names than

numbers.DNS plays a strong role in Server and

Internet functionality.DNS is the main name resolution

technique used in todays networks. Previous to this was the HOSTS file.

Show hosts file

DNS benefitsScalable – capable of adding mutliples names

to the database without affecting performance. Distributes workload among DNS servers.

Transparency – Host names remain constant even when associated IP address change.

Ease of Use – Use names to access resources instead of numerical IP addresses.

Simplicity – Users need to learn only one naming convention to find resources on the Internet.

DNS namespaceHierarchical – tree structure page 7.

Intro to DHCPDHCP – Dynamic Host Configuration ProtocolAutomatically assigns IP address to Hosts on

the network

Benefits of DHCPCentralized administrationDynamic host config –elimates need for

manually entering IP addressesSeamless IP host config – no user interventionScalability – scales from small to large

networks. Can add almost unlimited number of hosts.

Flexibility – Can easily change IP configurations when the infrastructure changes.

DHCP Relay AgentDHCP uses broadcast messages – routers

block broadcast messages so a relay agent must be used in between network segments.

Configuring clients without DHCPAutomatic Private IP addressing (APIPA) –

Windows machines that can not find a DHCP server will then be given an APIPA address. 169.254.X.X

Alternate Configuration – can be used when clients connect to a network that does not offer DHCP.

Routing and Remote Access RRASRRAS can allow us to use our Windows

Server sytem as a Router if we do not have one.

RRAS can allow clients to connect remotely to the server as if they were on the network. VPN is an example of this.

Network Access Protection NAPFeature that allows network admins to

specify policies that define who has access to the network.

Similar to BSC’s protection on Lab PC’sFor example if a computer is brought in that

has no Antivirus it will be put in a quarantined section so it can’t affect other clients on the network.

You Learned

Network protocols create a logical language that allows computers to communicate.

The most commonly used network protocol on modern networks is the Transmission Control Protocol/Internet Protocol (TCP/IP) protocol suite.

There are currently two implementations of TCP/IP: TCP/IP version 4, or IPv4, and TCP/IP version 6, or IPv6.

Lesson 1Lesson 1

You Learned (cont.)

Each host on a TCP/IP network needs to be configured with a unique IP address.

TCP/IP networks use the Domain Name System (DNS) to map human-readable machine names to IP addresses and vice versa, such as mapping the www.cpandl.com host name to the 10.10.1.104 IP address.

Lesson 1Lesson 1

You Learned (cont.)

DNS provides name resolution to allow meaningful names to be used to refer to network addresses.

DHCP is a simple, standard protocol that makes TCP/IP network configuration much easier for the administrator by dynamically assigning IP addresses and providing additional configuration information to DHCP clients automatically.

You Learned (cont.)

Network administrators can use the Dynamic Host Configuration Protocol (DHCP) to automatically assign IP addresses to multiple client computers.

Clients may be configured to use APIPA or an alternate static IP address configuration if DHCP is unavailable.

You Learned (cont.)

The Routing and Remote Access service provides the ability to use a Windows Server 2008 computer as a router, which passes network traffic from one TCP/IP network to another, as well as remote access capabilities using either dial-up or VPN technology

You Learned (cont.)

To allow administrators to enforce network security policies, such as mandatory anti-virus or firewall configurations, Windows Server 2008 has introduced the Network Access Protection (NAP) enforcement platform.