To connect with other network resources, you’ll need to know how to properly configure IP addressing in Windows. In this video, you’ll learn about IP addresses, subnet masks, default gateways, and alternate configurations.
When you start Windows, it obtains an IP address automatically by default. This means that most people can turn on their Windows device, they can browse the internet and use local network resources, and have no idea of the process that took place to assign an IP address to that workstation. This is the protocol responsible for finding a DHCP server, obtaining an IP address, and assigning that IP address to a local Windows device.
If a Windows computer starts up and it’s not able to find a DHCP server and a static address has not been manually assigned to the device, then it creates an automatic private IP address on that particular device. This is sometimes called an APIPA address.
This APIPA address is able to communicate with all other devices that are on the local network. In networking terms, we call this a link-local address. And you’ll know you’ve been assigned an APIPA address If the IP address is 169.254.1.0 through the value 169.254.254.255. One advantage to being assigned this APIPA address is at least you’re able to communicate with local devices, even though there’s no DHCP server.
Unfortunately, this means you’re not able to communicate outside of your local network, which means there’ll be no internet connectivity for anybody that’s assigned an APIPA address.
In some environments, a network administrator may not want to use DHCP, and they may not want to use an APIPA address. In those environments, the network administrator would manually assign a static IP address that would be permanently associated with that particular workstation.
To be able to manually assign these static IP addresses, there are a number of parameters that you’ll need to know. The first three parameters we have here are the foundation of IP addressing. You, course, need the IP address itself, which is a unique identifier that doesn’t match any other IP address that’s on the network. You then need a subnet mask that helps identify what particular IP subnet you’re a member of.
And lastly, you’ll need a default gateway. This is the device you’ll communicate to that allows for communication outside of your local subnet.
When most people use the internet, they communicate to devices based on a name, like Google.com or Professormesser.com instead of using the IP address of that service. To enable that functionality, you need to configure a DNS setting– or a Domain Name Services IP address. This is the IP address that will be used to convert the name to IP address so that you can then communicate directly to that device.
And depending on the configuration of your DHCP server, you may be assigned an IP address from an available pool of addresses, or there may be an address that is always assigned to your device, based on your Mac address.
And another important IP address is a loopback address. Every device on your network has a loopback address. And the default for all devices is 127.0.0.1. We often use this loopback address when we want to reference our local computer by IP address, and we know that everyone’s local computer will always be 127.0.0.1.
For our networks at home, there’s usually a single DHCP server, and it’s often integrated into our wireless router. In a work environment though, you need redundant DHCP servers, so there are usually multiple servers set up to provide IP addressing. However, there still may be times when a DHCP server is not available to a workstation. And as we mentioned previously, if you’re not able to get an IP address from a DHCP server, Windows will automatically assign an address using the automatic IP addressing scheme.
Windows includes another configuration for IP called the Alternate Configuration. This is the configuration that will be used if a DHCP server is not available, and you would prefer not using an APIPA address. This allows you to manually assign IP addressing, DNS information, and Win server information. That will be used if DHCP is not available.
And of course, you could always choose not to use DHCP and manually assign an IP address in your workstation. And that will be used every time you connect to the network.
Here’s the Control Panels Network and Sharing Center. I’m going to choose to change the adapter settings. I have a single adapter in this particular device. And if I right-mouse click, I can choose the properties for this adapter. This allows me to see all of the services and protocols assigned to this adapter.
And if I-double click on the IP Protocol Version 4, I can see the IPv4 details. This particular workstation is configured to obtain an IP address automatically from my DHCP server.
If I’d like to manually assign an address, I could choose to use the following address, and then I could type in that address, subnet mask, and default gateway manually.
If I do have this adapter configured to obtain an IP address automatically, then I have the Alternate Configuration tab, and that’s where I can assign a manual IP address that would be used if DHCP was no longer available. This allows the network administrator to choose the best way to assign IP addresses to their workstations, making sure that everyone has access to the resources they need.