Yes, each number can land somewhere between 0-255, but there are some default reservations on specific IP ranges.
For instance, 0 is typically used as an identifier for the subnet, not as an actual device IP. For instance, a DHCP server may tell a device “your IP address is 192.168.1.168. The subnet range is 192.168.1.0/24 (meaning the mask is 255.255.255.0). But the 0 won’t (or shouldn’t) get assigned to a specific device.
255 is another special address, as it is used for broadcast messages. A packet sent to 255 gets sent to everything in that subnet. So for instance, if I wanted to broadcast a message to everything on the 192.168.1.0/24 range, I would send it to 192.168.1.255.
In regards to reserved IP ranges, there are a few standard private IP ranges:
192.168.0.0/16 one of the more common. (Subnet mask of 255.255.0.0). This basically means that (if everything is configured properly) your WAN IP won’t ever be something inside of that same range, as the router would very quickly throw up its hands in defeat. Like if your WAN IP from your ISP was 192.168.1.50, and you also had a device on your network with that same IP address, the router wouldn’t know which one (WAN IP or LAN device) to send traffic to.
The second private IP range is 172.16.0.0/20 (subnet mask of 255.240.0.0) meaning the second number can range from 0-31, and the last two octets can range from 0-255.
The last common private IP range is 10.0.0.0/8, (subnet mask of 255.0.0.0) so the last three octets can range from 0-255. You tend to see these more in corporate settings, as it allows for a truly astronomical number of devices to be connected.
Basically, all of this means that if you see an address in the 192.168.x.x, 172.0-32.x.x, or 10.x.x.x range, you know it’s a private IP address, not a WAN IP.
Yes, each number can land somewhere between 0-255, but there are some default reservations on specific IP ranges.
For instance, 0 is typically used as an identifier for the subnet, not as an actual device IP. For instance, a DHCP server may tell a device “your IP address is 192.168.1.168. The subnet range is 192.168.1.0/24 (meaning the mask is 255.255.255.0). But the 0 won’t (or shouldn’t) get assigned to a specific device.
255 is another special address, as it is used for broadcast messages. A packet sent to 255 gets sent to everything in that subnet. So for instance, if I wanted to broadcast a message to everything on the 192.168.1.0/24 range, I would send it to 192.168.1.255.
In regards to reserved IP ranges, there are a few standard private IP ranges:
192.168.0.0/16 one of the more common. (Subnet mask of 255.255.0.0). This basically means that (if everything is configured properly) your WAN IP won’t ever be something inside of that same range, as the router would very quickly throw up its hands in defeat. Like if your WAN IP from your ISP was 192.168.1.50, and you also had a device on your network with that same IP address, the router wouldn’t know which one (WAN IP or LAN device) to send traffic to.
The second private IP range is 172.16.0.0/20 (subnet mask of 255.240.0.0) meaning the second number can range from 0-31, and the last two octets can range from 0-255.
The last common private IP range is 10.0.0.0/8, (subnet mask of 255.0.0.0) so the last three octets can range from 0-255. You tend to see these more in corporate settings, as it allows for a truly astronomical number of devices to be connected.
Basically, all of this means that if you see an address in the 192.168.x.x, 172.0-32.x.x, or 10.x.x.x range, you know it’s a private IP address, not a WAN IP.
The last time I was this confused reading something was when I was trying to under organic chemistry.