A public ip (or external ip) is the one you get from your ISP. This is the one used across the internet.
Whereas the one you get from your router is a private ip (usually its a 192.168.x.x one).
If, for some reason, you don't know what is your external IP-address, you can use one of available on-line detection tools: see related link.
192.168.0.254 is a valid "class C" IP address.
The difference is in the IP range. The multicast IP range is 224.0.0.0 - 239.255.255.255
255.1.0.0
255.1.0.0
IP address is categorized into IPv4 and IPv6. The IP is valid only if it is in the range of IP address range class. If you question whether or not the IP is really that of a safe site, you can do an IP lookup using an IP lookup tool. They are available free and can be found by doing a search using the term "IP lookup."
Class A IP address.
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192.168.x.x is an IP address in the private IP address range.
The class C range is 192.0.0.0 - 223.255.255.255
If you have changed DHCP ip range, the ip address for your router has changed too. You can find your router ip address in your wireless adapter information.
If your talking about a dial-up modem, it uses a public IP just like a ethernet card. It depends on your ISP, what range of IP addresses you are assigned when you connect (DHCP: automatically assigned IP address; IP address can change) or you could also have a static address( IP address is always the same).
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