Introduction to Networking Concepts
Introducing TCP/IP Addressing
 Network 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 IPv6
 IPv4 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 DNS
 DNS – 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 benefits
 Scalable – 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 namespace
 Hierarchical – tree structure page 7.
Intro to DHCP
 DHCP – Dynamic Host Configuration Protocol
 Automatically assigns IP address to Hosts on the
network
Benefits of DHCP
 Centralized administration
 Dynamic host config –elimates need for manually
entering IP addresses
 Seamless IP host config – no user intervention
 Scalability – 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 Agent
 DHCP uses broadcast messages – routers block
broadcast messages so a relay agent must be used in
between network segments.
Configuring clients without DHCP
 Automatic 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 RRAS
 RRAS 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 NAP
 Feature that allows network admins to specify policies
that define who has access to the network.
 Similar to BSC’s protection on Lab PC’s
 For 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.
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 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.
Lesson 1
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.