FastEthernet and Hubs : Auto Select
cards (like the popular 3COM
can operate at 10 Mhz or at 100 Mhz, depending on the
type of hub used for the connection.
Some hubs also offer the possibility to connect to
10 Mhz or 100 Mhz network cards : Dual-Speed Hubs
For easy of use, both the FastEthernet card and such Dual-Speed
hubs are usually configured
for automatic configuration : They are supposed to detect the
type of hub or network card and
then select automatically the proper connection speed.
That works in most installations very well, but (like usual) NOT
sometimes the hub and the network card do not work properly
together and the automatic
configuration fails: the network does not work (as it can be
tested via the
TCP/IP PING command).
As a first diagnostics, have a look at the indicators on your
With your PC powered on, hubs will usually indicate whether a
port is in use (for example
by a green light). Dual-Speed hubs usually also indicate the
detected / configured speed.
||try then to define
configuration on the PC:
In the Properties of the Network /
"Network Neighborhood", select
your network adapter and display
for it the Properties.
||Depending on the
the hub, predefine the "Media Speed"
to 10baseT or 100BaseTx.
Then test again the network
connection (for example using PING )
||Another possible reason :
While 10baseT -
coax Networking has only 1
allowing to have only one signal on the network cable,
Twisted-Pair networking uses multiple wires:
4 pairs, each pair twisted .
This allows to operate with multiple
a network signal can be send out, while another one
is received at the same time (if the hub is supporting
this functionality ).
Such simultaneous operation is called : "Full
If the network card or hub is only able to handle
ONE signal (sending or receiving), then this is
called "Half Duplex"
||Like the "Media
speed" , the hub and the network card
will configure themselves automatically for the proper
setting, but it maybe required to configure the
network card under "Duplex Mode"
"Half Duplex" to get
the network to run in some
I can not make a general statement, because in
such situations it is usally "trial-and-error" to fix