

Hi.

Please see RFC 1918 for a discussion on the use of IP addresses in
private networks.  The following address blocks are reserved for
private use and should never appear in the public Internet:

	192.168.0.0-192.168.255.255
	172.16.0.0-172.31.255.255
	10.0.0.0-10.255.255.255

The blocks of private address space are registered to the IANA on
behalf of the community of users of private address space.  The IANA
has no idea who these users are.  The same addresses could be used by
both Intel and IBM on opposite sides of the world, but since these
addresses are intended for private use, there should be no conflicts.

The point of private address space is to allow many organizations in
different places to use the same addresses for their disconnected
islands of IP talking computers (private intranets).

In most cases, when these addresses show up on the public Internet, it
is accidental, but there are some cases when it is being used
intentionally and illegally.

It is up to the user of the private space to see to it that the
private addresses are not visible in the public Internet.  The only
practical way to enforce this is for the public Internet service
provider that the private address space user connects to to filter out
any datagrams with source or destination private addresses.

Thanks.

IANA
