This is not how Ethernet works, nor is it how such a splitter works.

  Ethernet is a shared communications medium.  Every "packet" is tagged with
a destination *hardware* address, so there is no problem (except, in some
cases, performance) with multiple hardware destinations sharing a single
physical connection path.  (A hub simply delivers all packets to multiple
destinations, and leaves it up to them to recognize which packets bear their
address; a switch uses the hardware address info to forward packets only to
the intended destination.)
  None of that usually looks at the IP address; a single destination device
may have multiple IP addresses (although multiple addresses on the same NIC
can get complicated...).  In the other direction, the same link may be
carrying traffic for (hypothetically) EVERY address on the Internet, so
obviously that can't be a limitation of the technology.

  With splitters on both ends, you split up the four pairs(*) in the wiring
into two separate communications paths, no longer shared.  Unless you
physically only connect one path at a time, there's no way for traffic on
one path to prevent use of the other path -- except for the slight
possibility of electrical interference (crosstalk).

(*) Note that the splitter *requires* that all four paris be present and
connected, and while this is NORMAL, there may be old building installations
where only two physical pairs are present, and occasionally in cases with
four pairs there may be undetected damage to pairs that have not been in
use.  (If there were damage to an in-use pair, it would have been detected.)

David Gillett


On 7 May 2004 at 11:38, Craig Collins wrote:

> Mick,
>
> In theory it will be possible to connect both computers to your
> network/internet through that splitter. However, your
> computers/network cards will NOT SHARE that signal. Only one computer
> will be able to be "networked" at a time. The LAN connection that is
> routed to your wall socket is going to support only 1 ip address. Your
> computers would have to share that ip. Depending on your setup, you
> will need to purchase either a network hub or a network router to
> split your signal correctly. If you already have a router in your
> home/office then all you will need is a hub.
>
> Craig Collins
>
> Hammerhead Technology, Inc.
> 1406 Locust Street
> Chico, California 95928
> 800-951-9868
> 530-896-0490
> Fax 530-896-0493

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