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If you have an apple and I have an apple and we exchange these apples then you and I will still each have one apple. But if you have an idea and I have an idea and we exchange these ideas, then each of us will have two ideas.

– George Bernard Shaw

The computer world was similar to all of us having an apple each till some time back. And then the wise men from the industry made networks. Ideas started flowing all over and soon came in the internet. The internet has been the best thing that has happened to the computer world so far. It has created a platform where we can share our ideas.

Since the Internet is a large network composed of smaller networks, it made sense to break the address space into smaller chunks. Network classes enable us to break down this address space. In IPv4 the various classes of networks are -

Class A networks have an address range between 1.0.0.1 to 126.255.255.254 and support 16 million hosts on each of 127 networks.
Class B networks have an address range between 128.1.0.1 to 191.255.255.254 and support 65,000 hosts on each of 16,000 networks.
Class C networks have an address range between 192.0.1.1 to 223.255.254.254 and support 254 hosts on each of 2 million networks.
Class D networks have an address range between 224.0.0.0 to 239.255.255.255 and are reserved for multicast groups.

Class E networks have an address range between 240.0.0.0 to 254.255.255.254 and are reserved for the future

Such a system makes things simple and networks are manageable. However, they cannot communicate with each other. The scenario is very similar to how communities grew around the world. With time people from different communities needed to communicate with each other, however language was the barrier. The solution they found was people who understand both the languages i.e. translators. So if you need to talk to a beautiful French girl, all you need to do is get somebody who understands French and can translate English to French and vice versa. Routers /gateways do the same in computer networks. Different networks communicate with each other using routers.

A router allows hosts that are not on the same logical network, like an IP subnet, to communicate with each other. The router receives packets (chunks of data) on an interface and routes them to where they need to go based on a routing table; the table allows the router to have knowledge of where a given logical network is located.

Most offices and homes have small class C private networks. These networks need to communicate with the servers in the internet. The only logical way for them is to use a gateway/router. Linux has routing functionality in the kernel itself which makes it an ideal choice for as routing box.

One simple way of sharing the internet connection using linux is using the IP forwarding feature of the kernel and network address translation (NAT). For NATing one can use either ipchains or iptables. It is assumed that the private network is in the 192.168.1.0-255 range.
Let us take the example of a simple network. The server is used to connect to the internet. It’s IP address is 192.168.1.1. There are 4 workstations 192.168.1.2-5. They are connected to the server via the switch. All the workstations share the internet through 192.168.1.1

The first step is to enable ipforwarding in the kernel of the server (192.168.1.1).

$ vi /etc/sysctl.conf
Change the line
net.ipv4.ip_forward = 0

to

net.ipv4.ip_forward = 1

This would enable ip forwarding.

Then we need to get the server to NAT which can be done via ipchains or iptables.

If ipchains is used, create a file called rc.fw and add following lines

$ vi /etc/rc.d/init.d/rc.fw

#!/bin/bash

# First Load the ipchains kernel module. Required only if ipchains is compiled as a module
.
/sbin/modprobe ipchains
insmod ipchains

# MASQ the full 192.168.1.0/24 network
/sbin/ipchains -A forward -s 192.168.1.0/24 -j MASQ

# List the rules
/sbin/ipchains -L -n

If iptables is used instead of ipchains, create a file called rc.fw and add the following lines -

$ vi /etc/rc.d/init.d/rc.fw

#!/bin/bash

# First Load the ipchains kernel module . Required only if iptables is compiled as a module
/sbin/modprobe iptables
insmod iptables

# MASQ the full network
/sbin/iptables -t nat -A POSTROUTING -j MASQUERADE

# List the rules
/sbin/iptables -L

This would look after all the entire data traffic from the local network to the internet.

Finally add this to the startup -

$ vi /etc/rc.local

Add the line

/etc/rc.d/init.d/rc.fw

This ensures that the settings are retained after a reboot also.

After rebooting the server would do all the routing functions for the entire network.

On the client side all that is required is to set the default router/gateway as the server’s IP i.e. 192.168.1.1. The entire network is now set to share the internet connection.

Amarjyoti Krishnan heads bobcares.com, a tech support company for webhosts and ISPs. He is the co-founder of Poornam Info Vision Ltd., a software and IT services company which specializes in Linux based solutions for Webhosts and ISPs. Poornam Info Vision is an ISO 9001:2000 certified company with a team of over 100 engineers.

Amarjyoti is a Computer Engineer based in India and has over 7 years of experience in the hosting industry. He has spoken and written extensively on the subject. His articles have been published both online as well as in print in magazines.

http://poornam.com

http://bobcares.com

http://amarjyoti.com

Tags: computers, internet sharing, linux, technologycomputers, internet sharing, linux, technology

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Internet Service Provider or ISP is a company that provides access to the Internet.

Before choosing an ISP, it is important to assess your company’s business and marketing goals. You should find out what your organization will be using the Internet for. Once you’ve determined this, you can contact ISPs that serve your geographic area and ask them about their services. Those questions below will help you better understand that your local ISP offers.

Technical Questions About Reliability

1. Does the connection work at all hours of the day?

2. When are you busiest?

3. Does the connection support the speeds/types of hardware/software you want to use? Have specific questions to ask them. Know your operating system and the software that you need to use. Does the provider support 56K? Does it use the U.S. Robotics’ x2 or Rockwell/Lucent’s K56flex standard or both of them?

Technical Support and Troubleshooting

1. Is support part of normal service or an added cost?

2. What are the hours of coverage for network operations?

3. Is telephone support available via a local call, 800 number, or long distance?

4. Is there technical help available via e-mail? If yes who answers the questions and how soon?

5. Is there help and/or manuals available online?

6. Is there a user-friendly interface to Internet resources?

7. What software is provided and/or required?

8. Are the Internet tools that you need (such as e-mail, telnet, FTP, Usenet/News, Gopher, WAIS, WWW, or Lynx) available?

Business Arrangements and References

1. Are free trial connections available?

2. What local and 800 phone numbers are available for you to use?

3. Can multiple users access the same billing account simultaneously?

4. Can multiple user IDs/mailboxes use the same billing account?

5. Are there surcharges for any types of connections or particular hours of the day?

6. What kind of contract or services agreement is required?

7. What options are available for billing and payments? Discounts for pre-payments?

8. Are there refunds for early termination or if service is not satisfactory?

9. Are there any options that will reduce (or increase) your costs?

10. Are group discounts available? (Start your own group!)

11. After placing an order, how long does it take to make the connection active?

12. Are there charges for file storage?

13. Is space for Web pages included?

14. If you travel and want to access the Internet while you are on the road, ask about accessing your ISP from the cities you visit.

15. How long has the provider been in business?

16. Can you get answers to your questions in writing?

17. Ask for names of two to three similar users and check with them regarding their experience.

Written by Helen Peshkova, RichTrack.com.

http://www.RichTrack.com is one of the first business oriented education portals. It’s the leading online business information network for millionaires. The goal of RichTrack.com is to present business content in a professional, helpful and practical format that helps you getting rich.

Tags: internet, internet service provider, internet site, ISP, provider, web hostong, web provider, websiteinternet, internet service provider, internet site, ISP, provider, web hostong, web provider, website

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The invention and continuing popularity of the internet changed the way we live. Life certainly became a bit easier with the internet. With the internet, we now have the ability to search archives of files in the library, communicate with relatives half way around the world and we can now even shop for groceries right in the comfort of our own home.

It has changed the way we communicate and live our lives. Even businesses now use the internet as a tool for making more profit.

A few years ago, we accessed the internet using a modem; this would seem fast for someone who grew up using snail mail, but after the invention of high-speed internet, we now notice how slow a 56kbps dial up internet can be.

You might have experienced using a 56kbps dial up internet and after you typed in the website, it would seem that you can actually go to the kitchen make yourself dinner and after you come back to find out the webpage you typed isn’t even finished loading.

Today a speed of 256kbps and higher is considered a high-speed internet, it would seem that 56kbps is puny. It the time of the 56kbps internet, downloading a simple mp3 file could take a long time.

Today, the 256kbps high-speed internet gives you the ability to download full-length movies.

There are so many advantages with high-speed internet. One would be online gaming. It is now possible for people with high-speed internet to play with others from every part of the world with high-speed internet connection.

Another great feature is that you can update Windows protection software half the time a dial up internet can. Since many viruses are circulating the internet, your computer should have updated anti-virus software. The dial up internet is much more prone to viruses because of slow updates.

High-speed internet changed the way we communicate. With this technology, it is now possible for us to communicate not just by plain text but also through video and voice, much like a video telephone. The cost of putting up this technology in our home is very affordable. Almost everyone can afford it.

As the year’s passes, the demand for high-speed internet connection increases. Because of the growing demand, many companies opened as providers of high-speed internet and created competition. This increase in competition enabled people to afford high-speed internet.

The competition between providers did not only result into more affordably priced high-speed internet connection but it also caused a wide variety of products for high-speed internet connection. Some companies now offer VoIP phones. They also offer different high-speed internet packages that you can choose from to suit your needs.

Choosing the best high-speed internet providers is easy; all you need is a little time and effort.

Here are some few tips to keep in mind before you choose your high-speed internet provider:

Find out what you really need from a provider and estimate how much time you will be using the internet.

Bob Hett has extensively covered the Internet Service Provider industry as an analyst and has researched the various companies for factors based on price, reliability, support and overall quality. Learn more at High Speed Internet Service

Tag: High Speed Internet ServiceHigh Speed Internet Service

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