In this section, we’re going to define the relationship of client, server, and host computers according to your home network environment. We’ll also discuss the roles of these computers in regard to their responsibilities. When it comes to the client/server model, the possibilities are endless. In fact, client/server architecture is what makes the Internet possible.
Keep in mind that this is designed to give you a basic understanding of the client/server model according to your LAN (everything behind your router). It is far beyond the scope of this section to create an exhaustive resource for client/server architecture (such as website servers). However, the primary principals are identical. A server is still a server, and a client is still a client.
What is a Client?
A client is a computer hardware device or software that accesses a service made available by a server. The server is often (but not always) located on a separate physical computer.
What is a Server?
A server is a physical computer dedicated to run services to serve the needs of other computers. Depending on the service that is running, it could be a file server, database server, home media server, print server, or web server.
What is a Host?
A host is a computer, connected to other computers for which it provides data or services over a network. In theory, every computer connected to a network acts as a host to other peers on the network. In essence, a host reflects the logical relationship of two or more computers on a network.
To simplify this, suppose you want to download an image from another computer on your network. That computer is “hosting” the image and therefore, it is the host computer. On the other hand, if that same computer downloads an image from your computer, your computer becomes the host computer.
Your computer can be a host to other computers. Likewise, your router can be a host to other routers. But a host must have an assigned IP address. Therefore, modems, hubs, and switches are not considered hosts because they do not have assigned IP addresses.
How do I access a server?
A server can be located inside or outside of your LAN. Accessibility to the server is determined by whether or not it has a public IP address or private IP address. If the server has a public IP address, it can be accessed from the web. If it has a private IP address, it can only be accessed from inside of your LAN (unless you setup port forwarding for remote access).
The speed at which a client can retrieve data from a server is dependent on the amount of bandwidth required to transfer the data. If the server is on your LAN, your router will determine how quickly data is transferred from a server to the client. So if you have a good quality router, these days, that speed can be rather impressive.
This same logic applies to servers in your WAN (on the Internet). When you visit a web page, there are a number of things that determine how quickly the page loads:
- The speed of the server hosting that website
- How large the web page is (images, etc).
- How much bandwidth your ISP has allowed you
- How quickly your router can route data packets
- The speed of the Network Interface Controller on your computer.
So, bandwidth and latency play a huge role in the performance you experience between clients and servers.
What is the difference between a server and a host?
Client/Server architecture works much differently from file sharing technology such as Homegroup and Workgroup used by the Windows operating system.
- Can be a physical device or software program
- Installed on a host computer
- Provides specific services
- Serves only clients
- Is always a physical computer or device
- Can run both server and client programs
- Provides specific services
- Serves multiple users and devices
In a Windows Workgroup environment computers within the network merely access public folders on other computers. This scenario is common in home networks where one computer with a lot of hard drive space may host the media files for other computers to access.
With Windows Workgroup, there is no special server software running other than the operating system itself. Yes, the computer is still hosting the files and making them available to other computers; although, technically it is still not a server. In this scenario, it is considered a host. Why? Because one of the prerequisites of being a server is that it serves only clients.
The benefit of using Windows Workgroup is that you can easily access files and media on other computers within your LAN. The downside is that your files are not accessible from outside of your local network. If you want to access your files from outside of your LAN, you’ll need a server running on a host machine to pull it off.
Thankfully, a desktop computer with a static IP address can also function as a server. The following diagram is a depiction of this dual-purpose configuration.
In the previous illustration, the workstation computer is a client within the LAN. However, it is also a server. It’s running media server software which allows clients to access media files stored in a database. The server software queries the database and serves the media to the client computers.
In order for client devices to retrieve information from a host computer that is running server software, the client needs to know the hostname of the computer that is serving the data.
What is a hostname and host ID?
- The hostname is the name of the computer.
- The host ID is the physical address (the MAC address of the Network Interface Controller).
How do I find the hostname and Host ID of a computer?
If you are running windows 7:
- Click ‘Start’
- Type ‘cmd’ into the search bar
- When the cmd prompt opens, type “ipconfig /all” (without the quotes)
- Hit Enter on your keyboard
How do I access host computers on my network?
In Windows 7 you can reach host computers by clicking the hostname in the navigation pane, or by typing the private IP address.
In the example above, I’m accessing my Network Attached Storage (NAS) server which holds files and media that can be accessed from any computer within my LAN. In the example below, I’m able to achieve the same thing using the private IP address.
If you are trying to reach a specific folder on a network device, you’ll need to enter the full path to the folder. For example:
\\SERVER\Share . . .will take you to the top level folder
\\SERVER\Share\Videos . . .will take you directly to the videos folder.
or, . . .
If the server is not assigned a static IP address, the address could change the next time the server is restarted. This is yet another reason for assigning static IP addresses and then associating those IP’s with a computers hostname. This way, you can use the method above to quickly locate machines by using their hostname.
Also when accessing a host computer, you may be prompted for a username and password. Therefore, you’ll need to know the login credentials for a user on that machine.
If you prefer not to manually enter this each time you access a network device, simply select the checkbox in the login window to remember your login credentials.