By default, private IP addresses are assigned by the router and are dynamic, that is, they change. The router uses a system called DHCP to assign them.
The objective is for the private IP to be static, that is, it does not change.
The goal is to choose the private IP manually
Netplan is a program that comes with Linux to configure a static private IP using a file.
The private IP will go from being dynamic to static
Netplan chooses a static private IP for me, but it crashes my router when I add new rules.
If I set the IP to be chosen by DHCP, the router works again, that’s why I think the router should choose the IP and not Netplan.
The IP would still be chosen by DHCP but the router reserves the IP (that is, it saves an IP for a device using its MAC address).
The process you are looking for is commonly known as DHCP reservation or IP and MAC binding.
Find the DHCP Reservation option: Navigate through your router’s menus until you find a section that discusses DHCP settings, the list of connected clients, or “IP and MAC Binding.”
Bind IP and MAC address: Enter the MAC address you obtained from your PC and the private IP address you want to be permanently assigned to it (e.g., 192.168.0.249).
By doing this, your PC will continue to request an IP address via DHCP, but the router will remember the rule you created and will always assign it the same address.
This is the most reliable method for getting a static IP on a home network.
There is no “disallowed” range within private addresses.
In home networks, most routers operate on the 192.168.0.x or 192.168.1.x subnet. The range of available IP addresses is from .2 to .254.
.1 is usually reserved for the router
Choosing .249 is a good practice because it is an address that would not normally be automatically assigned by DHCP, since routers usually start assigning IPs from the beginning or end of the range.
The only “forbidden range” are special addresses such as .0 (network identifier) and .255 (broadcast address).
Other than that, any address between .2 and .254 is valid and safe to use statically on your private network.
Below are some images of the process:
