Home Networking John F. Samuels

“Dr. PC”

Copyright 2008 Dr. PC

Why?

Share data among computers Photos, Music, Video, Applications

Share one or more printers

Share an Internet connection

Work from your bed or garden

Tonight’s Agenda

•Networking Basics, Internet•Software, TCP/IP•Hardware, Wireless•Setting up a Network•Security, Printers, Tools•Troubleshooting

Network Basics Client-Server Networks

Users logon to server Security on server Data and programs on server

Peer-to-Peer Networks No “master” computer Can share all devices and files

Network Basics

Two types of physical connections for Local Area Network (LAN)

Wired – “Ethernet”

Wireless – “WiFi”

Network Basics

Peer-to-Peer Connection

Wired or WirelessFor wired connection requires

crossover type cable or hub for more than two computers

Network Basics

Wired Networks

“Ethernet” or “Twisted Pair” or nnbaseT Cabling – CAT(egory) 3,5,6

▪ 10 / 100 / 1000 mbps Up to 325 feet RJ-45 8 pin connectors Purchase or build your own

Network Basics Wired Peer-to-Peer Connection

Hub

Internet Connections

Dial-Up (AOL, PeoplePC, etc.) 50 kbps

DSL (BellSouth, others) 250-750 kbps

Cable / Satellite (Comcast, DirecTV) 750 kbps – 20 mbps

Internet Connections DSL Connections

Tel Line Filter Telephone

Filter Telephone

Modem CAT 5

Computer

ComputerUSB

Internet Connections

DSL with a WiFi ConnectionTel Line Filter Telephon

e

Filter Telephone

Modem, Router

Computer

ComputerCAT 5 or USB

Internet Connections

Cable Company Connections

Cable Cable Modem Router / HubCAT 5

Computer

Computer

USB or CAT 5 cable

Radio

Software

TCP/IP Users: Internet Explorer, Foxfire, Mozilla, Opera Outlook, Outlook Express, Eudora Microsoft Windows Update, Norton,

Panda, McAfee Itunes, Rhapsody LapLink, VNC, PCAnyWhere

TCP/IP - 1 Puts your data (packet) into an envelope,

addresses the envelope, and puts a return sticker on it. If it is too large for one envelope, it breaks it up into more packets and sends it on its way. And does much more.

A TCP Address is NNN.NNN.NNN.NNN where NNN is 0-255

Ex.: 192.168.254.1 or 10.10.1.0 Maximum of 254 addresses in a LAN

TCP/IP - 2

Local or Private TCP Addresses: 192.168.0.0 10.0.0.0 172.16.0.0 127.0.0.0

DHCP in your computer or router assigns that TCP address dynamically, or you can set it manually.

TCP/IP - 3

Q: How can I connect to the world through an Internet connection if my TCP address is the same as many others?

A: A router will get a single external TCP/IP address from a DHCP server at your Internet Service Provider (ISP) and will route all communications properly between your LAN and your ISP.

TCP/IP - 4

DHCP Server

ISP

Telephone line or cable

MODEM Router

DHCP Com

p 2Comp 1

68.104.32.17

68.104.32.17

192.168.100.1192.168.100.2

Internet

TCP/IP - 5

Domain Name Server (DNS)

DNS

68.87.74.16268.87.68.162

www.ebay.com =66.125.194.100

ISP

Telephone line or cable

MODEM Router

DHCP Com

p 2Comp 1

68.104.32.17

68.104.32.17

192.168.100.1192.168.100.2

Internet

Routers

ISP

Telephone line or cable

MODEM Router

DHCP Com

p 2Comp 1

68.104.32.17

68.104.32.17

192.168.100.1192.168.100.2

Internet

DNS

68.87.74.16268.87.68.162

www.ebay.com =66.125.194.100

Hardware

A Hub has no intelligence – it just connects computers together (layer 1)

A Bridge understands the MAC address and connects multiple LANs (layer 2)

A Switch is like a Bridge but has some intelligence (layer 2)

A Router does all the above and understands the TCP/IP addresses (layer 3)

A Wireless Access Point (WAP) is a radio

MAC

Each communication device in the world is supposed to have an unique MAC address. This is used by TCP/IP to keep track of all of your computer adapters.

A MAC address looks like this:

02-00-54-55-4E-01

Wireless Types

“WiFi”-”Hot Spot”

4 Types (see chart) 6 Radio Channels in

2.4 gHz range Encryption

Type Speed (mbps)

Distance

B 10 75

A 10 100

G 54 125

N 108 150

Belkin Wireless Modems (WAP)

Linksys WRT54G Routers

D-Link Routers

Belkin “N” Router

Setting up a LAN -1

Install modem and hook to telephone line or cable

Install telephone line filters if DSL Install router and Ethernet cable to

modem Install power to modem. Wait for

power-up diagnostics to complete OK Install power to router. Install provided programs/drivers in

computer Install USB or Ethernet cable to

computer

Setting up a LAN - 2

Computer will recognize new hardware and install drivers

Open MS Internet Explorer. The Home Page should be displayed.

Share disk or folders Install network printers or other

devices Set passwords and encryption Update firmware in router

Network & Internet Connections

Set up a wireless network

Network Setup Wizard

Wireless Network Setup

Network Name

Set Up Options

Save to flash drive

Network Connections

Local Area Connection Status

Choose a Wireless Network

Security 1

Once you have a wireless connection… Your neighbor’s teenage son will not only

use your Internet connection to download music, videos and porn, but he will modify the router to open up ports for music sharing and gaming, and he will set a password of his own so that you cannot regain control over the router. In his spare time he will install a keystroke logger in your computer to obtain your passwords, make transfers from your bank account, and steal your identity.

Security 2

To prevent this all you have to do is:

1. Logon to your router and assign your own (secure) password.

2. In Wireless Security set one of the levels of encryption and key:WEP, WPA or WPA2

3. Do the same in each wireless device

IEEE 802.11i Standards

WEP – Wired Equivalent Privacy Old, insecure, but better than nothing.

Prevents casual snooping.

WPA – Wi-Fi Protected Access Implements most of the privacy standards, but

may not work with older devices (Palm).

WPA2 – includes all mandatory security standards and new AES algorithm.

Security 3

To logon to your router first find out the address by using the DOS command ipconfig /all. The Default Gateway is the router address.

In a browser, such as IE, type that address in the address bar and Enter

The router screen should ask for a logon name and password.

Security 4

Very often the original password is “admin”. Use Internet search to find the right one for your router.

Go to the Administration section and set your own password (and don’t forget it). Don’t forget to Save Settings.

Follow your router’s help screens or Documentation or contact the help desk at your ISP to set up encryption on your router.

Adding a Printer - 1

On computer with printer attached Start – Control Panel – Printers [and faxes] Right click on printer to be shared and

select Share In Sharing tab click on Share This Printer

and give it a name, maybe Brother 7420 Apply and OK Sharing can be done for folders too or

whole disk (c:). Public or SharedDocs are always shared.

Adding a Printer - 2 On remote computer Start – Control

Panel – Printers [and Faxes] Select Add a Printer In Vista reply Network and double click

on the computer name that has the printer

In XP reply Next in the wizard▪ Click on A Network Printer and Next▪ Select Browse for a Printer and Next

Select the desired printer from the list and Next

The printer will be installed

Tools

Start – Run – Cmd will open a “DOS” window. Ipconfig /all will show you basic

information about your adapters and addresses.

Ipconfig /renew will find all of the devices on your LAN and renew the TCP/IP addresses.

Ping [site] will send a query to the remote site and measure the time for a reply.

Tracert [site] will list all of the nodes between you and the site.

Netstat

IPCONFIG Output

PingMicrosoft Windows [Version 6.0.6001]Copyright (c) 2006 Microsoft Corporation. All rights reserved.

C:\Users\John>ping my.yahoo.com

Pinging my.yahoo4.akadns.net [68.142.197.198] with 32 bytes of data:

Reply from 68.142.197.198: bytes=32 time=83ms TTL=49Reply from 68.142.197.198: bytes=32 time=77ms TTL=49Reply from 68.142.197.198: bytes=32 time=82ms TTL=49Reply from 68.142.197.198: bytes=32 time=84ms TTL=49

Ping statistics for 68.142.197.198: Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),

Approximate round trip times in milli-seconds: Minimum = 77ms, Maximum = 84ms, Average = 81ms

C:\Users\John>

Tracert

Troubleshooting

Update firmware in router Network Troubleshooter Repair Connection Unplug modem, router and turn off

computer; replug modem and wait until power-up sequence is complete; replug router; power-up computer

Disable firewall and virus software Use tools – ipconfig, ping Call ISP service desk

That’s All Folks