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 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.

Lesson 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 host name to the 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.

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.