What is Your IP Address?

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A network may contain multiple computers or others devices each having their own IP address (multiple addresses in some cases).

Reasons Why You Need to Know Your IP Address

A person does not need to know their IP address in normal day-to-day online use, but it is useful information to have in certain situations.

When working in an office environment, technicians from the Information Technology (IT) department may ask you to provide your work computer's current IP address for the purpose of remote troubleshooting.

Knowing how to quickly look up its address can be a time saver.

On home networks, a person usually needs to know the address of their broadband router in order to administer it.

On any kind of network, looking up IP addresses helps with network troubleshooting:

  • A device that shows address failed to receive a dynamic address from the DHCP server, has its wireless radio shut off, or has not been assigned a static IP address.  
  • A Windows computer that shows addresses starting with 169.254 has been configured by APIPA due to the local DHCP server being unavailable.
  • If an IP address conflict is suspected on the network, inspecting the address values of each device is needed to determine which are using the same ones.
  • Devices showing an address outside the local network's address range generally indicates a mobile device that failed to release its address obtained from a different network it was connected to earlier.

    Looking at a client's IP address settings also tells whether a given network supports only IPv4, only IPv6 or both.  

    Older peer-to-peer (P2P) applications shared IP address information with other users to facilitate connections, but newer technology has eliminated the need to do this. People should avoid advertising their public IP address with other P2P users whenever possible.

    Finding Your IP Address

    Internet sites such as whatismyipaddress.com can automatically detect my IP address when accessed through the Web browser. These sites only work if that computer is connected to the Internet. On a home network these sites may not find that computer's address but the address of the router instead.

    To determine your IP address in various scenarios, see - How to Find Your IP Address.

    How Others Can Determine Your IP Address

    Other people can figure out your IP address in certain situations: