About
The public IP is the ip address located in the public network (ie Internet).
They are global addresses that are unique across the internet.
Usage
Internet Access
At home or at work, you have another IP called the private address. This address is translated by a network translation function.
The devices that need to be publicly identified, such as:
- or mail servers,
must have a globally unique IP address; and they are assigned a public IP address.
Firewall
Firewalls use this IP to block public connections.
Registration
In order to maintain uniqueness within global namespace, the IP addresses are publicly registered with the Network Information Center (NIC) to avoid address conflicts.
How to know your public IP?
To determine the public IP address, if the computer is:
- not behind a proxy, use one of these links:
- behind a proxy, use one of these links to determine its true IP address: