cross over cable

I have two machines with redhat 9. Will a cross over cable hooked to each
network card work or will I need to use a hub?

On Fri, 26 Dec 2003 23:22:25 -0600, thudd <(E-Mail Removed)> wrote:
> I have two machines with redhat 9. Will a cross over cable hooked to each
> network card work or will I need to use a hub?

Yes, a crossover cable is usually best because everything is connected
directly from Tx/Rx on one to Rx/Tx on other full duplex (if capable).
Although, in rare cases if using old 16-bit 10/100 card it can be too fast
for the card capabilities or 16-bit bus, which might make it erratic (I
had a Linksys pc card like that, but a newer version of same model was
smoother).

A switch is nearly as good (full duplex) because it directly links nics
together that are communicating at the time. At one time it was cheaper
for me to get an extra nic and tie 3 PCs together with 2 xover cables, but
switches have come down in price. I now have a combination
switch/printserver that has 4 ethernet ports and 2 parallel printer ports.

A hub is usually slowest, because everything is half duplex at the speed
of the slowest nic (like a party line where only one nic can communicate
at a time, which can be slowed by retransmissions due to data collisions).

--
David Efflandt - All spam ignored http://www.de-srv.com/

thudd wrote:

> I have two machines with redhat 9. Will a cross over cable hooked to
> each network card work or will I need to use a hub?

Crossover works fine. You will need to set a static IP for both.

--
robert - redhat & slackware

David Efflandt wrote:

> On Fri, 26 Dec 2003 23:22:25 -0600, thudd <(E-Mail Removed)> wrote:
>
>>I have two machines with redhat 9. Will a cross over cable hooked to each
>>network card work or will I need to use a hub?
>
>
> Yes, a crossover cable is usually best because everything is connected
> directly from Tx/Rx on one to Rx/Tx on other full duplex (if capable).
> Although, in rare cases if using old 16-bit 10/100 card it can be too fast
> for the card capabilities or 16-bit bus, which might make it erratic (I
> had a Linksys pc card like that, but a newer version of same model was
> smoother).

Crossover cables can often be used, but I wouldn't call them "best."
I've seen credible reports of problems with direct NIC/NIC connections
(having to do with autonegotiation as I recall).

>
> A switch is nearly as good (full duplex) because it directly links nics
> together that are communicating at the time. At one time it was cheaper
> for me to get an extra nic and tie 3 PCs together with 2 xover cables, but
> switches have come down in price. I now have a combination
> switch/printserver that has 4 ethernet ports and 2 parallel printer ports.

If there's a "best" it's probably a switch, which will maximize speed,
flexibility, and even cost if more than a couple of machines are
involved. In "olden times" (i.e. a couple of years ago), the higher
cost of switches made hubs popular.

I would argue that a switch is BETTER than a crossover cable except in
very limited cases of little interest. You seem to have reached the
same conclusion when you replaced your crossover cables with a switch.

>
> A hub is usually slowest, because everything is half duplex at the speed
> of the slowest nic (like a party line where only one nic can communicate
> at a time, which can be slowed by retransmissions due to data collisions).
>

I think that "at the speed of the slowest nic" clause is incorrect,
unless you just mean that throughput of a connection is limited by the
slowest link in the chain directly involved -- but that's true of a
crossover cable connection, too. One slow NIC on a hub will NOT force
all the others to slow down to its speed (unless they're talking to the
slow one, of course). Collisions can also be an issue, but will not
normally control throughput to that great an extent.

--
After being targeted with gigabytes of trash by the "SWEN" worm, I have
concluded we must conceal our e-mail address. Our true address is the
mirror image of what you see before the "@" symbol. It's a shame such
steps are necessary. ...Charlie