We have a netra X1 which seems not to like our ethernet. We can
install it fine (so it has no trouble doing reads), but if we try and
do something like connect an X session to it, it is either unusably
slow or doesn't work at all (connection just hangs). This all smells
of some failure to negotiate duplexness with the hub but I don't think
it's that.

We have a tiny 3com officeconnect 10/100 hub (which I think must be
some kind of switch really, since it can (and does) support 10 and 100
simultaneously on different ports). The netra ends up running at
100Mb, half-duplex, which is the same as the other machines modulo the
router which is at 10 on one of the ports. Between other machines I
can get close to 10MB/sec with this setup so I don't think there's
anything wrong with the hub.

If I connect the netra with a crossover cable to a random laptop
(dlink card?) then there is no problem at all.

Has anyone seen anything like this? It's kind of a pain... I'm
wondering if I should just speculatively replace the hub but how do I
know the replacement will be better? And what should I get that's not
too expensive anyway?

An unrelated question: the manual for the netra says it takes standard
PC133 memory. Does this mean I can (modulo support questions) go to a
random PC shop and buy memory for it? What about parity &/or ECC,
does it not have this (eek!)?

Thanks

--tim

Approximately 9/16/03 07:28, Tim Bradshaw uttered for posterity:

> We have a netra X1 which seems not to like our ethernet. We can
> install it fine (so it has no trouble doing reads), but if we try and
> do something like connect an X session to it, it is either unusably
> slow or doesn't work at all (connection just hangs). This all smells
> of some failure to negotiate duplexness with the hub but I don't think
> it's that.

You would be thinking wrong pretty much 99.9999% of the time
this type of symptom occurs.
>
> We have a tiny 3com officeconnect 10/100 hub (which I think must be
> some kind of switch really, since it can (and does) support 10 and 100
> simultaneously on different ports). The netra ends up running at
> 100Mb, half-duplex, which is the same as the other machines modulo the
> router which is at 10 on one of the ports. Between other machines I
> can get close to 10MB/sec with this setup so I don't think there's
> anything wrong with the hub.

If that is a hub, that Netra is gonna eat it for lunch and
you'll have trouble getting any sort of thruput between any
of the other ports while the Netra is using the LAN.

>
> If I connect the netra with a crossover cable to a random laptop
> (dlink card?) then there is no problem at all.

In other words, there appears to be nothing wrong with the
Netra or its ethernet....
>
> Has anyone seen anything like this?

Yes, only a few thousand times. It is usually someone with
false economy using a cheap hub with an expensive server capable
of saturating a 100BaseT port in full duplex.

If it isn't misuse of a cheap hub, it is misconfigured auto
negotiation 99.99999999999% of the time.

> It's kind of a pain... I'm
> wondering if I should just speculatively replace the hub but how do I
> know the replacement will be better? And what should I get that's not
> too expensive anyway?

You could eBay a cheap Cisco, but they are notorious for not
auto-negotiating with many of the Sun NIC's. However at least
you would have the ability to manually configure full duplex
on the Netra port.

Some folks have had good luck with the small Linksys *SWITCH*
[not a hub] or NetGear *SWITCH*. Make sure whatever you get
has a management interface that allows setting port duplex and
speed manually if necessary. And remember that if you set one
end of a physical cable link to manual, you *must* set the other
as well or you are guaranteed a duplex mismatch.

On Tue, 16 Sep 2003 23:07:57 +0000, Lon Stowell wrote:

> Some folks have had good luck with the small Linksys *SWITCH*
> [not a hub] or NetGear *SWITCH*. Make sure whatever you get
> has a management interface that allows setting port duplex and
> speed manually if necessary. And remember that if you set one
> end of a physical cable link to manual, you *must* set the other
> as well or you are guaranteed a duplex mismatch.

The LinkSys EZXS88W switch provides failure-free autoneg with the hme NIC
and it has no management interface. After all, it retails for $59.99 at
compusa.com.

On Wed, 17 Sep 2003 00:39:25 +0000, Lon Stowell wrote:

> Yeah, I've used the same model successfully, but all it would take
> is an obstinate interface and you have no way to "adjust its
> attitude" without a mgt interface. Am actually connected to
> an EZXS55W at the moment. An expensive Intel managed NIC refused
> to autonegotiate, most of the cheap ones do so perfectly.

From one box to the switch I use a Cisco patch cable. When I had a box
with an Intel 82558 in it connected through that cable I had no such
problems. Replaced the box with one containing an Intel 82557 and totally
lost connectivity. So I replaced the 82557 with 82558 and autoneg again
works perfectly.

When the 82557 was connected using an ordinary cat-5 patch cable autoneg
worked reliably.

The only NIC which would not autoneg was a real DEC NIC in an AlphaServer.
There are a couple of settings in SRM and Tru64's /etc/inet.local file
which will force the tulip NIC to 100TX F/D however.

* Lon Stowell wrote:
>>
>> The LinkSys EZXS88W switch provides failure-free autoneg with the hme NIC
>> and it has no management interface. After all, it retails for $59.99 at
>> compusa.com.

The Netra X1 doesn't have an HME interface (the other machines talking
to this hub, which do, work *fine*). It has something called DMFE
(Davicon <something> Fast Ethernet I guess). And once again: it's
negotiated the same stuff all the other machines have.

--tim

* I wrote:
> [stuff in response to something it looked like I thought Lon Stowel
> had said but actually Dave Uhring said]

I screwed up the followup, sorry. And now I can't work out how to
drive article cancelling in gnus any more.

--tim

Approximately 9/17/03 02:55, Tim Bradshaw uttered for posterity:

> * Lon Stowell wrote:
>> Yes, only a few thousand times. It is usually someone with
>> false economy using a cheap hub with an expensive server capable
>> of saturating a 100BaseT port in full duplex.
>
> Well, it's running 100MHz 1/2 duplex, same as all the other Suns using
> that hub (all HMEs I think). They all work, it doesn't. It doesn't
> work if I force full-duplex either (which I wouldn't expect it to, but
> I tried it - haven't tried forcing it to 10MHz yet). Hmm. it also
> doesn't see any packets on the wire after a bit - well, snoop doesn't,
> but the ethernet port does, at least judging by the LEDs.
>
> And try not to be *quite* so patronising, why don't you?

It is difficult not to be patronizing after seeing the
conclusion that this is anything other than a duplex
issue. Try pulling netstat -k [ifname].

* Lon Stowell wrote:
> It is difficult not to be patronizing after seeing the
> conclusion that this is anything other than a duplex
> issue.

Did you think I didn't bother to check that it was 1/2 duplex before
posting, and just said `oh, it's bound to be not a problem'? I am
quite willing to believe it's the hub but it definitely isn't a duplex
problem.

Never mind, I'll ask Sun, they're less offensive.

--tim