Re: 10/100 NIC Recommendations?

[Mike Johnson <mike johnson GSC GTE COM>]

At 11:46 PM 2/27/99 -0500, you wrote:
>>>>>> "p" == paul  <paul hessels sheridanc on ca> writes:
>
>p> At this point I am a little confused.  What controls the rate the card 
>p> runs at.  Does the card control that?  The kernel?  I have a SMC 
>p> EtherPower 10/100, plugged into a hub set at 10half.  Firstly, I need 
>p> to change the port so it is running at 100/full, but what do I need to 
>p> change on the machine itself?  I'm confused......
>
>The card should auto-detect the fastest speed the hub can handle, so
>you don't need to change anything on the machine. 
>The card and the hub are the only things involved, however from the
>hub on is another matter.

I wanted to make one little point here.  You cannot plug a NIC into a
garden variety hub and run full-duplex.  Except for some strange hubs
(switching hubs?), you must have an ethernet switch to run at full-duplex.
When a NIC runs at full-duplex, all collision controls are disabled (hence
the extra speed).  Since a switch only sends traffic where it's supposed
to go, there's -usually- no collisions between switch ports.  However, in
a hub, all traffic is repeated across all ports, so collisions will happen
and the collision controls of half-duplex are needed, otherwise your network
will go to hell in a handbasket.  Ray's right, though.  The card should
auto-detect what's best (unless you have an auto-negotiating hub, in which
case the hub and the card negotiate the fastest) and switch to it.  Keep in
mind, though, that if you only have a 10Mbit hub, your SMC will choose
10Mbit, as it should.

>Ray Curtis         Unix Programmer/Consultant   Curtis Consulting

Mike

--
Mike Johnson - mike johnson gsc gte com
Network Engineer - Prototype Development
GTE Government Systems - All opinions are mine, not GTE's.