Knowing your IP address may not be vital in most everyday cases.
If you’re an average user, you may never realize that your IP address has changed.
However, changing the IP address has mechanisms that may not be clear to everyone.
As a result, you may want to know when the IP address changes.
For example, does it change with Wi-Fi, or does every network has a fixed address?
Does IP Address Change With Wi-Fi?
Your IP address changes every time you switch your network.
It happens when you go from cellular to Wi-Fi or from one Wi-Fi router to another.
This change happens because each internet company has a limited number of IP addresses they automatically assign to devices.
Every time a device goes offline (e.g., you turn off your laptop or PC), the ISP assigns your IP to another device that wants to connect to the internet.
Once you turn your device back on, the ISP looks through its pool of available IPs and gives one to you.
However, your IP address may even change while you’re connected to the same router and your device is on.
That’s because your IP expires after one to five days, depending on your ISP.
If your device stays connected to the network longer, it has to ask the ISP to maintain its current assignment before the clock runs out.
If the ISP doesn’t renew the “lease,” you’ll experience a short disconnection while your device receives a new IP.
This briefly explains the Dynamic Host Configuration Protocol (DHCP), which allows ISPs to serve many customers using a limited number of public IP addresses.
Note that this process happens automatically when you connect to the internet because your internet company takes care of all the settings and configurations.
However, if you have a local network without an internet connection, you or someone with the experience will have to apply the configurations.
Understanding IP Addresses
When you connect to the internet, you join an overwhelmingly vast pool of devices connected to each other and the world wide web.
These devices and connections need a way to identify themselves to avoid confusion, maintain security, and make communication easier.
IP addresses are like postal addresses that make your location known to senders.
Your unique IP address is a set of four digits that the ISP assigns to you based on your location.
When you visit a website, the IP address helps it identify the receiver to send you your requested data.
Modem Vs. Router IP
Every device that connects to the internet must have an IP address to make it known to other devices and the entire network.
Whether you connect to the internet on your smartphone, laptop, or even an IoT device, they receive the information they request via their IP addresses.
The same thing applies to the modem and router.
Both devices require IP addresses to receive and send information, but the kind of IP assigned to each device is different.
That’s where we should know the difference between private and public IP addresses.
1. Public IP Addresses
The public IP is the address that makes your network known to outside networks.
The IP address changes whenever you change your Wi-Fi connection or turn off your modem and turn it back on.
Public IPs are unique and made of meaningful strings of numbers that show your country but don’t show your exact location.
Since each IP is unique, your IP address changes when you connect to a different Wi-Fi network.
This type of IP address is network-related and not device-related.
That means your IP will change even if you take your router/modem to a different location.
The public IP is assigned to your network connection.
Your IP will change when you connect to a new connection with the same router.
2. Private IP Addresses
When you bring the internet to your home via the modem, you usually use a router to connect different devices to the Wi-Fi network.
The router also needs a unique IP address if you have a separate modem and router.
In addition, each device needs its unique IP address to make it known to the router.
This way, the router knows which device to route data and connection to.
All other devices connected to the local area network, including the router, get a unique local IP.
Local IPs look like public IPs, consisting of four sets of digits, but they’re unique only inside the local network.
That means you can find the same IP address for many devices connected to different local networks.
In other words, your smartphone may have the same local IP address in your home network as it does on your work network.
It only needs to be different from the IP addresses of other devices connected to the same network.
When it comes to the wider network, the public IP address is required, which is unique across the entire network.
Now, you can see the difference between a modem and a router’s IP address.
The modem has a public IP since it connects you to the outside world, whereas the router has a local IP address because it’s part of the local area network.
If you have a modem/router combo, it has both a public and a private IP address.
Other Types Of IP Addresses
Your IP changes when you connect to a different Wi-Fi because it’s public and unique.
In addition, the IP will change even when you’re connected to the same Wi-Fi network.
However, not every IP address changes that way because we have two other types of IP addresses, dynamic and static.
1. Dynamic IP Address
Most IP addresses are dynamic, especially those used by average internet users.
Thanks to the DHCP (Dynamic Host Control Protocol) standard, you get a new IP address whenever you turn on your modem.
Internet Service Providers have a pool of IPSs purchased from a higher-level provider.
When you turn off your modem/router, your IP is assigned to another user.
In addition, the IP is leased to you for a fixed amount of time, a maximum of five days.
When the lease expires, the ISP gives you another IP.
The best thing about dynamic IPs, apart from being free, is that it’s safe.
When IPs change regularly, it’s difficult for hackers to hack you through your IP address.
In addition, the dynamic nature of IP assignments means you don’t need to go through official steps to get a new IP when you change your location.
You can get it automatically without you even knowing it.
2. Static IP Addresses
With the dynamic addresses being clear, you can understand how static addresses work.
As the name suggests, static addresses don’t change, but you may never need them under normal circumstances.
You only need them if you have a business that hosts a website or has servers.
Some websites also require their subscribers to always connect through the same IP.
In such cases, you also need to use a static IP.
In that case, your IP always remains the same and only changes when you connect to a different Wi-Fi network.
3. Mobile Data IPs
When you connect to the internet via your mobile data, you also get an IP address from your Internet Service Provider, which is now the cellular data provider.
The public IP makes your device known to the outside network and enables communication from your device.
However, you don’t get a private (local) IP because there’s no local network.
There’s only one device and one connection.
Mobile data IPs are also dynamic and change when you turn off your cellular data back on.
How To Get A Static IP Address
Local and public IP addresses are usually dynamic, but you can change them to static for security reasons or simplicity.
For example, if you have different devices connected to the same local network, you may need to know your device IP for performing advanced network activities like remote access through Wake-On-LAN.
That’s because you need to know your device IP to access it, which can be difficult if it changes or expires.
To assign a static IP address, both local and private, you need to know your device’s MAC address.
The MAC address is the physical address unique to your device and specified by your device manufacturer.
It’s related to hardware, and nobody can change it.
Here’s how to find your MAC address for each device:
You can find your PC’s MAC address by referring to its user manual.
Still, you can find it via Settings > Network & Internet > Status.
Click View hardware connection and properties to see the device’s MAC address.
You can see different MAC addresses for different connection types, like Ethernet and Wi-Fi.
2. Mac Devices
Your Apple computer’s MAC address is accessible through the Apple menu > System Preferences > Network.
Here again, you can see the MAC address for different connection types.
Select the connection and click Advanced > Hardware > MAC Address.
After getting your MAC address, you can get the static IP.
3. Android Phones
Getting your smartphone’s MAC address is very simple.
You only need to go to the device Settings > About Phone.
You can find your MAC address under Status or Hardware Information.
You may find two types of MAC addresses for your device: Device MAC and Wi-Fi MAC.
To find Wi-Fi MAC, go to Settings > Wi-Fi > Additional Settings > MAC Address.
To find your iPhone’s MAC address, go to Settings and tap General > About > Wi-Fi Address.
That is your Device MAC, but you can find the Wi-Fi MAC through Settings > Wi-Fi.
5. Local Network Static IP
You need to enter your router’s configuration interface to get a static local IP address.
To do so, you need your router’s IP.
Open a command Prompt window and enter ipconfig/all.
Look for Default Gateway, copy the number in front of it, and paste it into your browser’s search bar.
Enter your username and password—which are both “admin” if you haven’t changed them before.
Once inside the router’s web interface, look for the settings for static IP.
Different routers may have different words to refer to the same setting, but you should look for Reserved DHCP or Reserved IP Address under Advanced Setup and LAN Setup.
When you find the correct setting, you should provide your device’s MAC address and choose a static IP.
If you’re unsure about your device’s MAC address, you can find it under Device Info > DHCP in your router’s web interface.
6. Public IP
Since internet service providers set public IPs, you can’t get a static IP address through your router.
After finding your device’s MAC address, contact your ISP to allocate a static IP to you.
However, it depends on the ISP, their policies, and whether they give static IP addresses to their clients.
Why Do IP Addresses Change?
Not only does your IP change when you switch to a different Wi-Fi connection, but it also changes frequently when you’re connected to the same Wi-Fi.
Now you may wonder why IP addresses should change.
Wouldn’t it be easier if they remained the same for every connection and device?
Apart from security reasons, there are also technical reasons.
Penetrating the device will be more difficult when you have different IP addresses.
Here’s the technical reason: IPs are assigned through the IPV4 protocol, which uses a numerical system with more than four billion numbers.
That means the protocol can assign unique IP addresses to four billion connections.
However, the number of connections may be much more than that.
Millions and millions of devices are connected to the internet at the same time every day.
Assigning a static IP address can be difficult, requires massive logistics, and may not be enough.
As a result, it’s better to automatically circulate these addresses among the connected devices by taking those belonging to off devices and assigning them to active ones.
Changing The IP Address
As mentioned earlier, changing the IP address helps you maintain security.
In addition, it’s more convenient for users to have addresses automatically assigned to them.
Occasionally, you may need to change the IP address manually for different reasons.
For example, the IP address previously assigned has errors and creates problems for your connection.
The best way to change your IP address is to turn off your modem, wait a few minutes, and turn it back on.
Switching to a different network also gives you another IP.
However, you may also need to change your IP address because of network limitations.
As mentioned, the IP address shows which country you’re connected from.
Changing the IP address will help you bypass the restrictions for specific locations, like when a website doesn’t allow users of a particular location to access its content.
In such cases, you can use a VPN to get an IP address that belongs to a different country.