WEB HOSTINGModule 3: Domain Name System (DNS)

INTRODUCTIONThe domain name system (DNS) indicates your domain name what hosting account to connect to. An example of a DNS would be:

ns1.webhostingforstudents.net ns2.webhostingforstudents.net

When you get a hosting account, it will tell you the DNS for the server.

You should then add these DNS settings to your domain name with your domain name registrar.

MODULE OBJECTIVESUpon completion of this module, you should be able to:

• Define a Domain Name System• Describe how DNS works• Differentiate types of web hosting

providers including:o ISPo Free Web Hostingo Paid Hostingo Domain Hosting

• Apply your knowledge to compare and contrast web hosting providers.

WHAT DNS DOES

DNS is simply a database that links meaningful names (known as host names), such as http://www.example.com, to a specific IP address, such as 192.168.124.1.

Linking addresses to names is just the beginning, because DNS has many other features in addition to host-name-to-address mapping.

Mappings of addresses to names and vice versa are stored in a database that is distributed.

DNS databases also store additional records.

HOW DNS WORKS

Each DNS server maintains only a small portion of the total DNS host to IP address mappings. Each DNS server is configured with a special record that tells the DNS server where it will perform a lookup for records it doesn’t have in its portion of the DNS database.

When looking for a name in DNS, the DNS client first checks a top-level DNS server database. That server tells the client which DNS server hosts the next part of the DNS name, and the client then queries that server. This lookup-and-handoff process continues until the client finds the DNS server that hosts the DNS record in question, and that server provides the IP address.

Let’s see..PAYING ATTENTION?

Select the correct options. Then move on to the next slide to check your answer.

Which of the following statements are true about DNS?

DNS database is not distributed

Each DNS server maintains only a small portion of the total DNS host to IP address mappings

DNS is simply a database that host names, to a specific IP

Let’s see..PAYING ATTENTION?

Which of the following statements are true about DNS?

DNS database is not distributed

Each DNS server maintains only a small portion of the total DNS host to IP address mappings

DNS is simply a database that host names, to a specific IP

Select the correct options. Then move on to the next slide to check your answer.

DNS PROPAGATION

When DNS changes are made (like switching hosting providers or switching from an old website to a new one) every DNS server in the world needs to update its records of what IP is associated to a domains. It takes some time for every DNS server in the world to update its records. So until they all update the to the new DNS / IP information one might have the old info while one might have the new info.

So let's say we are launching a new site coolexample.com on a different web server and we update the DNS records. Let's also say that the DNS server I use has updated with the new information and I go to coolexample.com and I see the new site but the DNS server you use hasn't updated and you go to coolexample.com and you see the old site. This is because the new DNS updates haven't propagated to the DNS server you are using yet.

HOSTING PROVIDER

Web hosting is the service that makes your website available to be viewed by others on the Internet. A web host provides space on its server, so that other computers around the world can access your website by means of a network or modem.

There are literally thousands of web hosting services available today, ranging from free services with limited options to expensive, specialized business web hosting services. Which option you choose depends primarily on how you plan to use your website and how much you want to spend.

TYPES OF WEBHOSTING SERVICES

FREE WEB HOSTING

PAID HOSTING

INTERNET SERVICE PROVIDERS (ISPS)

DOMAIN HOSTING

Many people put up their first websites through their ISPs, because it's generally easy and inexpensive. Most ISP service packages include a

small amount of free web space, along with tools to create and upload websites quickly and easily. ISP websites are perfect for people who

want to put up small sites with low amounts of traffic. However, there are usually rate restrictions, and most ISPs don't offer a lot of features, so they might not be the best choice for a thriving business website.

TYPES OF WEBHOSTING SERVICES

FREE WEB HOSTING

PAID HOSTING

INTERNET SERVICE PROVIDERS (ISPS)

DOMAIN HOSTING

Free web hosting is another good option for smaller, personal websites. There are many free hosting providers that offer all types of features; some include CGI access and more. The drawback to most

free hosting services is that they are funded by advertising that appears on your site, so free web hosting so generally best for

personal, rather than business, websites.

TYPES OF WEBHOSTING SERVICES

FREE WEB HOSTING

PAID HOSTING

INTERNET SERVICE PROVIDERS (ISPS)

DOMAIN HOSTING

With paid hosting, you pay a fee for space and services on a web hosting provider's server. Monthly fees can range from a few dollars to

several hundred dollars. Obviously, the more you pay, the more features you should have at your disposal. Services can include CGI

access, database support, ASP, e-commerce, SSL, additional space on the server, extra bandwidth, and more.

TYPES OF WEBHOSTING SERVICES

FREE WEB HOSTING

PAID HOSTING

INTERNET SERVICE PROVIDERS (ISPs)

DOMAIN HOSTING

A good option for small businesses is to pay for domain hosting. Domain hosting allows you to host your site anywhere you like: on an ISP, a free hosting service, or even your own server. You buy a domain

name and have the provider forward all requests for that domain to the actual web location. This is often less expensive than buying both the domain and the hosting service, and it allows businesses to brand

their URLs.

Let’s see..PAYING ATTENTION?

Select one of the options. Then move on to the next slide to check your answer.

Which hosting would you recommend for a low-traffic personal website?

Paid Hosting

Free Web Hosting

ISP

Domain Hosting

Let’s see..PAYING ATTENTION?

Select one of the options. Then move on to the next slide to check your answer.

Which hosting would you recommend for a low-traffic personal website?

Paid Hosting

Free Web Hosting

ISP

Domain Hosting

Free web hosting is a good option for good option for smaller,

personal websites.

PRACTICE TASK

Take some time to research and complete this task.

1. Purchase a domain name and hosting account to use for this course. (We recommend Web Hosting for Students).

2. Point the domain name DNS to your hosting account

3. Login to your hosting control panel and look around the control panel

4. Login to your hosting control panel and look around the control panel

5. Try accessing your site using the IP address or temporary URL (if provided)

CONGRATULATIONS! You should now be able to:

• Define a Domain Name System• Describe how DNS works• Differentiate different types of web

hosting providers including:o ISPo Free Web Hostingo Paid Hostingo Domain Hosting

• Apply your knowledge to compare and contrast web hosting providers.