Re: Netra X1 ethernet strangeness, & memory type

From: Lon Stowell (lon.stowell_at_comcast.net)
Date: 09/17/03 

Date: Tue, 16 Sep 2003 23:07:57 GMT

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.

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