Solutions for small business computer networks

By Crawley Ashford
Computers have become very much a part of lives today. With each passing day we are becoming more and more dependent on the wonder machine. They are absolutely essential as regards businesses. As regards small businesses the first and foremost thing that would be necessary is to have an efficient and effective computer network setup at the work place. A computer network essentially means linking up of the computers in the office area. The most important advantage of having such a system in place is that it saves plenty of time. Small businesses are no different and they too would benefit hugely with having such a system in place. Small businesses also use computers for their day to day smooth functioning. There are companies which offer exclusive small business computer network. This could help in the effectiveness of the business operation.Computer network installation is the first step in having an integrated computer system at the work place. There are experts in the field that lend their services for doing so. Once the computer network installation is completed the functioning of the business enterprise becomes easier. A well-established computer network setup helps in the growth of the business. If not, with such tough competition around it is likely that businesses which do not use the potential of the computers to the fullest will be left out in the race. Companies which set up the computer network also provide the computer network maintenance. Such enterprises provide the necessary computer network maintenance from time to time and this ensures that the network system functions smoothly or else it may result in huge losses for your business. For the smooth operation of any business computer network solutions is absolutely essential. A small business computer network is as important as that of a large business enterprise. A good computer network would help in file sharing which would help in saving time. The use of other devices can also be shared. For e.g. an integrated computer network system would result in the sharing of peripheral devices such as the printer and this would invariably save money for the enterprise. Over a period these savings would make a huge difference especially in case of small business enterprises. Data can be shared at a faster pace and there can be a smooth flow of information and communication. Even data recovery is more effective with such a network system in place. If one computer fails due to any reason such as a hardware problem then the data can be recovered from another system where it has been saved. So this also makes it a safe system of operation. All Computer network solutions can be found with the firms that offer computer network installation and other services. A good computer network at an office place has far reaching benefits for the business enterprise and its growth. It is best to approach a well known company that offers such services and have an effective computer network setup in place at the earliest.

Crawley Ashford consults for small business without an IT Department or with an IT Department in setting up computer networks, IT Network Spam Filter , IT Network Firewall setup, Hawaii IT Services & Support, Small business computer network cabling , IT Consulting, Product Sales, Programming.
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IT Network Support and Solutions

By Crawley Ashford
Information Technology (IT) has become a major part of our lives. Any business or office is almost completely dependent on computers today for their operation. Once an office is computerized it may tend to have problems with the hardware or may end up with some software related issue some time or the other. To take care that the functioning of the business is not affected due to these problems most companies hire the services of an IT services firm which would provide it with the necessary IT support that it needs from time to time. In case of any problem this firm would give the IT solutions that are required to overcome the problem.
IT experts do a wide variety of jobs which include designing and installation of computer networks, managing the system and various other tasks. Some IT support lending firms have such advanced technology that they identify a problem at a very early stage and that tends to work as a warning system. This works as an alarm and major problems can be avoided and huge expenses can be prevented. The IT services firm monitors the functioning of the system and being a continuous process, problems are identified and addressed at the earliest saving both time and money.
Hiring a competent IT services firm is of utmost importance as it would have all the IT solutions which would make the functioning of the business an absolutely smooth process. Over a period the systems tend to slow down and a firm which has the right expertise would help you deal with this issue by monitoring the system and providing effective maintenance at regular intervals. The most well equipped firms offer many of their services right from their office and this would help in saving a lot of time. They are even capable of identifying a failing hardware which would ensure that no data is lost as recovery measures can be setup at the earliest.
Security issues are a big concern as far as computer networking is concerned. A capable and proficient technology support partner would help in getting the very best out of your system. Most of the time companies install programs that are available locally but at times there is a requirement of programs which are to be made with certain specifications meeting the demands of the company. Such IT solutions can be brought about only with a well experienced team of an efficient IT services firm.
If the network is managed by an experienced hand then you can concentrate completely on the functioning of the business. There are such firms which look into the needs of small business enterprise alone. Such competent firms also have well experienced staff to attend to every problem at the earliest and offer the very best solution. One should conduct a thorough survey before hiring the services of any such firm. There are plenty of such IT services lending firms but an efficient one is of utmost importance as the functioning of your enterprise is largely dependent on their service and effectiveness.

Crawley Ashford consults for small business without an IT Department or with an IT Department in setting up computer networks, Hawaii IT Services & Support, IT Network Spam Filter, IT Network Firewall setup, IT Consulting, Small business computer network cabling, Product Sales, Programming.
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Build a Local Area Network

By SAGAR
IntroductionIf you want to transfer some of your data files from one computer to another in your office what will you do? One option you have is to take a floppy or CD and copy the data into it from source computer and go to destination computer and download the file in it. This method is very much time consuming and also you can not copy the data more then 1.44MB in floppy and around 800MB in CD. What if you have more than 2GB or more data to transfer? Here we can use LAN. A LAN is a group of two or more computers that can share information and resources. You can have 1000’s of computer in your LAN depending on the size of your organization as long as the computers are kept in one building or location. Here I am going to tell you how to build a small Local Area Network of 5-10 computers. First of all we need to know the equipments that are required to setup a LAN.
Computers: - Obviously you need 2 or more computers to build a network because one computer can not make a Network
Cables: - Depending on your network size and utilization you can select the category of the cables. For a small network you can use CAT5 cable which supports 10/100Mbps speed. However you have option to purchase Cat 6 Cable also which support speed of up to 1Gbps. Here I will use CAT5 Cable. (Want to know more about CAT5 click here)
Hub / Switch: - This is a device the will be put in a central location and all the PCs will connect to it. These devices can be of 4, 8, 16, or 24 ports. They come with more ports also. These days switches are being used everywhere as they are more advance then HUB.
NIC: - Network Interface cards are required for you PCs. Here also you have option to get a card of 10/100 or 10/100/1000Gbps speed. Again it depends on your requirement and budget. One end of network cable will connect to NIC in your computer and another end will go to switch. Note: - Most of the computers these days comes with built in network card so you don’t really need to purchase NIC if you already have one on your computer’s motherboard.
RJ45 Connector: - These are small jacks that need to be punched at both ends of cables. You don’t need to buy these connectors separately because readymade cables are available in market but of course if the desired length cable is not available then you will have to get the RJ45 Connectors and punch them at both ends of cable as per the cabling standard.
Once you have all the equipments you are ready to do connectivity among your computers and some windows settings. Follow the steps below to get your network up and running.
Step1: - Open your computers one by one and install the NIC. As I mentioned above if you have built in network card on your computer’s motherboard then you don’t need to do this activity. Better you buy PC with built in network card this way you can save lots of time.Step2:- Connect all the computers one by one to your hub/switch. Once you connect all the computers just power on the switch.Step3: - Now you have you to do some settings in your PC. All the PCs should have a unique identification so that another computer on network can identify it. Just in human beings we know people with their names, in computers they identify each other with their unique IP Address. These are 32 bit octets in the form of 0 and 1. We write IP address in the decimal form like 192.168.1.1. You have two options to provide IP address one is manual by sitting on each computer and typing the IP address and another is through DHCP Server. You can say DHCP server as a service of Microsoft Windows 2000/2003 Server which automatically provide IP address to computers as soon as they boot. (Click on DHCP to know more about it.) For a small network of 10-20 PCs you don’t need DHCP server but for big network it would be very confusing and time consuming to provide IP address manually. In our scenario you can give IP address manually because we are setting up a network of just 10 PC. Now log in to PCs with administrative privilege and follow the steps below to give IP address to PCs.
a. Click on Start – Settings – Network Connection and then double click on Local Area Connection.b. From the new Window click on properties and on the new window scroll down to select internet protocol TCP/IP. Double click on it or click on properties to give IP address.c. On the opened window give an IP address in the space provided. Just below IP address there is an option of subnet mask. As soon as you will give the IP address the subnet mask will come automatically depending on the Network Class you have selected. (Click on Network Class to know more about it.)
Once you are done just save the settings by clicking on apply and OK. Repeat all 3 steps above on all your computers but remember to give unique IP address to each computer. You can check the connectivity among the computers by running a command called PING on each computer. Just go to command prompt and type ping IP ADDRESS (For example Ping 192.168.1.1) you should get reply from another computer which has the IP address 192.168.1.1, remember the PC you are trying to ping should be switch ON. If you get a message saying REQUEST TIME OUT that means the PC you are trying to ping is switch off or there is some problem in the connectivity. So you will have to check it.
These settings are enough to get your LAN up and running how ever in IP settings page you have some more options that you can define as long as you have installed these services in you network. For example DNS, Gateway or WINS, you can click on each of these words to know more about them.

Sukhsagar Prajapatihttp://www.techdatainfo.blogspot.com
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The importance of TCP/IP and its use in the Internet

By Jagdip Singh
Many people may not know what TCP/IP is, nor what its effect is on the Internet. The fact is, without TCP/IP there would be no Internet. And it is because of the American military that the Internet exists.
During the days of the cold war, the defense department was interested in developing a means of electronic communication which could survive an attack by being able to re-route itself around any failed section of the network.
They began a research project designed to connect many different networks, and many different types of hardware from various vendors. Thus was the birth of the Internet (sorta). In reality, they were forced to connect different types of hardware from various vendors because the different branches of the military used different hardware. Some used IBM, while others used Unisys or DEC.
TCP (Transmission Control Protocol) and IP (Internet Protocol) were the protocols they developed. The first Internet was a success because it delivered a few basic services that everyone needed: file transfer, electronic mail, and remote login to name a few. A user could also use the “internet” across a very large number of client and server systems.
As with other communications protocols, TCP/IP is composed of layers. Each layer has its own responsibility:
IP is responsible for moving data from computer to computer. IP forwards each packet based on a four-byte destination address (the IP number). IP uses gateways to help move data from point “a” to point “b”. Early gateways were responsible for finding routes for IP to follow.
TCP is responsible for ensuring correct delivery of data from computer to computer. Because data can be lost in the network, TCP adds support to detect errors or lost data and to trigger retransmission until the data is correctly and completely received.
How TCP/IP works
Computers are first connected to their Local Area Network (LAN). TCP/IP shares the LAN with other systems such as file servers, web servers and so on. The hardware connects via a network connection that has its own hard coded unique address – called a MAC (Media Access Control) address. The client is either assigned an address, or requests one from a server. Once the client has an address they can communicate, via IP, to the other clients on the network. As mentioned above, IP is used to send the data, while TCP verifies that it is sent correctly.
When a client wishes to connect to another computer outside the LAN, they generally go through a computer called a Gateway (mentioned above). The gateway’s job is to find and store routes to destinations. It does this through a series of broadcast messages sent to other gateways and servers nearest to it. They in turn could broadcast for a route. This procedure continues until a computer somewhere says “Oh yeah, I know how to get there.” This information is then relayed to the first gateway that now has a route the client can use.
How does the system know the data is correct?
As mentioned above, IP is responsible for getting the data there. TCP then takes over to verify it.
Encoded in the data packets is other data that is used to verify the packet. This data (a checksum, or mathematical representation of the packet) is confirmed by TCP and a confirmation is sent back to the sender.
This process of sending, receiving and acknowledging happens for each individual packet sent over the Internet.
When the data is verified, it is reassembled on the receiving computer. If a package is not verified, the sending computer will re-send it and wait for confirmation. This way both computers – both sending and receiving – know which data is correct and which isn’t.
One nice thing about this protocol is that it doesn’t need to stick to just one route. Generally, when you are sending or receiving data it is taking multiple routes to get to its destination. This ensures data accuracy. Just the facts:
TCP/IP addresses are based on 4 octets of 8 bits each. Each octet represents a number between 0 and 255. So an IP address looks like: 111.222.333.444.
There are 3 classes of IP addresses:
ranges starting with “1” and ending with “126” (i.e.. 1.1.1.1 to 126.255.255.254) are Class A ranges starting with “128” and ending with 191 (i.e.. 128.1.1.1 to 191.255.255.254) are Class B ranges starting with 192 and ending with 254 (i.e.. 192.1.1.1 to 254.255.255.254) are Class C ( You will notice that there are no IP addresses starting with “127”. These are reserved addresses.)
Calculating an IP address
One of the things that always confused me was how to convert IP address to their Binary form. It is quite simple really. IP addresses use the Binary numbers (“1”s and “0”s) and are read from right to left.
Each position in the binary address corresponds to a number, from 1 to 128 and look like this:
128 64 32 16 8 4 2 1
To calculate an address, simply add the numbers where a “1” appears. For example, the following: 00001010 works out to 10. Like this: 0 0 0 0 1 0 1 0 128 64 32 16 8 4 2 1
You can see that the “1”s line up with the 2 and 8 – when you add 2 plus 8 the answer is 10.
Since an IP address contains 4 of these octets, it can be displayed in binary like:
00001010.00001010.00001010.00001010
Therefore, IP Address 10.129.254.1 would be converted to:
00001010.10000001.11111110.00000001 (8+2) . (128+1) .(128+64+32+8+4+2).(1)
While it’s not important for the average person to know how to figure this stuff out, it is important for someone setting up a small network. That is because TCP/IP also uses what are called subnet masks to determine which addresses are valid. But I won’t get into those for now. And it’s also a neat trick that you can use at parties to show your non-techy friends just how much of a technology geek you are :)
So there you have it – a brief introduction into TCP/IP – the foundation of the Internet.

Did you find this article useful? For more useful tips and hints, points to ponder and keep in mind, techniques, and insights pertaining to computers, software, viruses and data recovery, do please browse for more information at our websites.
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TCP/IP Programming
in C

Client-Server Model

Definitions

• Server - a process which is able to receive and respond to properly formatted requests from other processes.

• Client - a process which is able to request information from a server on the same host or on a different host.

Requirements for Network Interfaces

Both Server and Client

• Sending and receiving processes must be able to execute on any host

even on the same host

even on different hardware and OS

• Guarantee data integrity

• Handle disconnection in a well-coordinated fashion, including:

  • informing the other side of the connection

  • informing the user

  • closing all files

Client Only

• Ability to address the specific server it requires

• Built small – not too demanding on the client host

Server Only

• Able to support multiple clients...

and multiple simultaneous requests...

from different hosts

• Usually on more robust and responsive hardware

• Main processing of the system is done here

IP Addressing and Protocol

• Provides a method of addressing any

station on the network

• Management and diagnostic services

• Packet size limitation

Three types of addresses

• Ethernet

• IP

• Port number

Purpose Format Used

Ethernet Address Low level Addressing 6 short integers Routing tables

(hardware address) within Ethernet “burned into”

IP Address Long distance and 4 short integers Inter- Intra-Net

“dotted quad” program addressing adrressing

Port Number Identify one process One long 32bit Values Name up to

within a host integer 1024

TCP/IP Client - Server Addressing

When the Client specifies:

1. IP Address >>> Tells which Host

2. Port Number >>> Tells which Server Process

within Host

After IP . . .
Next Level of Protocol
Can be either . . .

TCP or UDP

connection oriented no connection datagram

reliable delivery (expects non-reliable delivery

acknowledgment)

point to point broadcast

non-guaranteed record guaranteed record boundaries

boundaries

socket parm=

SOCK_STREAM SOCK_DGRAM

Important Address & Protocol Functions

Provide information about:

• Host names as configured by

  • Hosts files

  • DNS

  • NIS

• Protocol names

• Services

  • names

  • Port numbers

  • Protocols

gethostbyname - retrieves all information about a host, given its name or IP. This works whether the name is stored in /etc/hosts, NIS or DNS.

/etc/hosts should contain a single line for each host with the following information:

<internet address><official host name><aliases>

For example:

192.45.36.5 hpdxsg testhost

If your system is in a domain naming environment, an official host name consists of the full domain extended host name.

For example:

5. hpdxsg.xsg.hp.com hpdxsg testhost

getprotobyname - gets a protocol number, given its name. Used for finding the protocol number for TCP or other protocols used in calling other routines.

#The form for each entry is:

<official protocol name><official protocol number><aliases>

#Internet (IP) protocols

#

ip 0 IP #internet protocol, pseudo protocol number

icmp 1 ICMP #internet control message protocol

ggp 3 GGP #gateway-gateway protocol

getservbyname - receives 2 arguments:

(1) char * - service name or alias

(2) char * - protocol name (tcp or udp)

#The form for each entry is:

<official service name><port number/protocol name><aliases>

echo 7/tcp #Echo

echo 7/udp #

TCP/IP Socket Functions

Server/Client/ Order

Both of Call Purpose

accept S 4 Wait for client connection

bind B 2 Associate socket with IP address

connect C 3 Requests connection to a server

listen S 3 Allocates queue for clients

recv B 5 Receives data block by length from a socket

send B 5 Sends a data block to a socket with opt.

IP address

shutdown B 6 Shutdown socket as directed

socket B 1 Allocate memory areas with port/address

read B 5 Inputs a text line from a socket

write B 5 Outputs text to a socket

TCP/IP Normal Sequence

Client Server

1 socket socket

2 bind bind

3 connect listen

4 accept

TCP/IP Support Functions

Purpose Param Returns

gethostbyname Retrieve a host IP address host name 1. name

2. aliases

3. addrtype

4. addrien

5. addrlist

6. 1st addr

getprotobyname Retrieve the internal protocol name 1. name

protocol number 2. aliases

3. number

getservbyname Check for existence of serv name & protocol 1. name

of given services 2. aliases

3. port

4. protocol

getpeemame Find IP address of remote socket address remote IP addr

communication host

getsockname Find socket address of socket address local IP addr

open socket

Steps in Making a TCP Connection

1. Query system information

gethostbyname-

getprotobyname-

getservbyname

2. Open a “socket” to allocate data structure

3. “Bind” the socket to attach it to the local address

4. (For servers) Allocate a “listen” queue to wait for a connect

request to pass its server address.

5. (For servers) Perform “accept” to allow an incoming

request to pass its socket address.

All data transfers use this passed socket. The server “accept”

socket is still available to service other incoming connections.

6. (For clients) Perform “connect” to request connection to a

given server IP address and port number.

Introduction

Computer Viruses

– Causes

– Cures

– Prevention practices

l Participant discussion

– Worst virus story

– What you hope to learn today

l Virus infections on computers, while not ‘life’ threatening, affects us in the workplace by:

– Slowing down - stopping production

– Diverting attention

l Virus prevention is a combination of:

– Knowledge

– Backups

– Anti-virus software

Vocabulary

l Terms

– Back Door

– Bug

– Firewall

– Hack

– Intrusion

– Signature Files

l Virus Types

– Trojan Horse

– Worm

– Macro

– Boot Sector

– Parasitic

History of Computer Viruses

First viruses came from Bulgaria, possibly Pakistan

– Boot sector virus, spread from floppy to floppy

What Is a Virus?

l Executable computer code that has the ability to spread by replicating itself

– Part of the code can be destructive or mischievous

– > 40,000 identified viruses

– No computer is immune

– Millions of dollars spent in production loss and clean-up

Life Cycle of a Virus

l Creation

l Replication

l Activation

l Discovery

l Assimilation

l Eradication

Common Virus Types

Boot Sector

l File Infector

l Multi-partite

l Macro

Boot Sector Virus

l Most common through 1980s and 1990s

– Spread via the boot sector on floppy disk to user’s hard drive

– ‘Sneakernet’ spread of virus was slow

– Virus removal simple

l Boot from uninfected floppy

Replace MBR (master boot record

File Infecting Viruses

l Parasitic viruses

– Operate in computer’s memory

– Infect executable files

l .COM, .EXE, .SYS, .BIN

– Found in Macintosh, Pre-Windows PCs, computers with limited security

Multi-Partite Viruses

l Boot Sector virus characteristics

l File infecting virus characteristics

– Jerusalem Virus

– Parity Boot Virus

Macro Viruses

l 60-80 percent of all viruses

l Not specific to operating system

l Propagation:

– Email attachments

– Floppy disks

– Web downloads

– File transfers

l Melissa, Nimda, WM97

Sources of Infection

l Floppy disk

l ‘Shared’ applications

l Internet

– Email

– Web

l LAN

– Shared folders

WAN Delivery of Viruses

l Viruses can propagate very quickly over Internet

– Nimda propagated around the world in less than a week

l Harder to isolate and eradicate

– More factors involved

– More computers, systems involved

Protection and Management

l Isolate your data from your applications

– Application folder

– Data folder

l Keep your data on the file server

– Backup data daily

– Keep several backups

l Have a disaster recovery plan

– Operating system

– Applications

Protection and Management #2

l If using newer operating systems, do not log in with administrative permissions

l Use anti-virus software

– Maintain signature files weekly

l Keep operating system current

– Service patches

l Keep applications current

– Service patches

Common Sense Approach

l Do not open mail from unknown addressees

l Do not use pirated copies of software

l If you don’t know what a file does or who it is from, don’t execute it

99% of viruses need to be run

Post-Virus Recovery Procedure

l Isolate computer

– Try to identify virus

– Try to identify source

– Try to disinfect with anti-virus software

– Reinstall operating system

Reinstall applications

Ten Immutable Laws of Security

l If a bad guy can persuade you to run his program on your computer, it’s not your computer anymore

l If a bad guy can alter the operating system on your computer, it’s not your computer anymore

l If a bad guy has unrestricted physical access to your computer, it’s not your computer anymore

If you allow a bad guy to upload programs to

Ten Immutable Laws, Cntd

l A machine is only as secure as the administrator is trustworthy

l Encrypted data is only as secure as the decryption key

l An out of date virus scanner is only marginally better than no virus scanner at all

l Absolute anonymity isn’t practical, in real life or on the web

l Technology is not a panacea

Ten Immutable Laws, Cntd

l A machine is only as secure as the administrator is trustworthy

l Encrypted data is only as secure as the decryption key

l An out of date virus scanner is only marginally better than no virus scanner at all

l Absolute anonymity isn’t practical, in real life or on the web

l Technology is not a panacea

Summary

l Viruses are a waste of time and money

l Form of cyber-terrorism

l Can be dealt with – common sense

l Start backing up your data

l Make sure your anti-virus signature files are current

Information Technology Education

By Michael Bustamante

If you are seeking a decent income and a job with multifaceted appeal, then perhaps an information technology education might be in order. With the field of information technology (IT) expanding at an incredible pace, an information technology education could be your one-way ticket to professional success!
Information technology schools often present a comprehensive curriculum in administration, development, maintenance, and support of computer information systems. Additionally, students may opt to become qualified in specialty systems such as Cisco and Microsoft, whereby students are given in-depth instruction in how to design, install and maintain computer networking systems. Other information technology training may involve intranet communications and connections, microcomputer applications and installations, network administration, computer repair, and general maintenance of computer systems.
An information technology education may lead to several certifications including A+, CCNA, MCP, MCSA, MCSE, or Network+. Depending on level of experience, education and specific field of expertise, those who have successfully completed their information technology education can qualify for employment as Computer Support Specialists, Data Communications Analysts, Network Support Technicians, Network/Systems Engineers, PC Technicians, Systems/Network Administrators, or Wireless Network Technicians.
If you would like to learn more about Information Technology Education as well as Information Technology Schools and even Online Information Technology Schools, you can find more in-depth information and resources on our website.
DISCLAIMER: Above is a GENERAL OVERVIEW and may or may not reflect specific practices, courses and/or services associated with ANY ONE particular school(s) that is or is not advertised on SchoolsGalore.com.
Copyright 2007 - All rights reserved by SchoolsGalore.com, in association with Media Positive Communications, Inc.
Notice: Publishers are free to use this article on an ezine or website, provided the article is reprinted in its entirety, including copyright and disclaimer, and ALL links remain intact and active.
Michael Bustamante is a staff writer for Media Positive Communications, Inc. in association with SchoolsGalore.com. Find Information Technology Schools, Colleges, Universities, Vocational Schools, and Online Schools at SchoolsGalore.com, your educational resource to locate schools.
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