Why Do 16-Block IP Blocks Have 13 Usable Addresses?

Stephen Carville stephen at totalflood.com
Wed Dec 15 19:05:22 UTC 2004


On Wed December 15 2004 10:40 am, Will wrote:
> When you are assigned a 16-block (/28) IP address block by an
> ISP, why are only 13 IPs usable?   I was told that the first and
> last addresses in the block are not usable, and the 14th address
> is the gateway.   What are the first and last address used for?

First adddress is the network ID, last address is the broadcast address.

-- 
Stephen Carville
Unix and Network Adminstrator
DPSI
6033 W.Century Blvd.
Los Angeles, CA 90045
310-342-3602



More information about the bind-users mailing list