two questions

Peter Green
Fri Nov 12 10:11:49 1999

On Fri, Nov 12, 1999 at 11:28:59PM +0900, wrote:
> > I understand. However, I've tried three different (identical chipset) cards.
> FWIW, the Realtek 8139 is the most problematical chip I have ever used.  I
> also have three of these cards, and swapping cards never solves a problem.
> I've never observed the type of problem you're suggesting, but I'm almost
> ready to trash all of mine, too.  My cards only have problems once or twice
> a month, but, that's still too often for me.

These are supposed to go into a remote machine (over 500 miles away); that's
enough reason for me to dump these buggers. However, I'll continue pursuing
a fix for the problem for posterity's sake.

> > It is completely symmetric:
> > 
> > A->B ==> A.TX++, B.RX++
> > B->A ==> B.TX++, A.RX++
> Hmm.  Not likely cabling then.  Have you tried using "tcpdump" to view
> traffic on the line?  These machines must have some sort of two way
> communication before a ping can actually be sent.  At a minimum you would
> need the sender to first issue an arp request and receive an arp reply before
> a ping could be sent.  You should be able to see all of that with tcpdump.

Machine 'A' has the Realtek. Pinging B->A yields the following with tcpdump
on A:

09:47:55.568312 P [|llc]
0:0:0:0:0:0:0:0:0:0:0:1 0004 0:

One of those per ping. Pinging A->B yields the following with tcpdump on A:

09:48:00.789675 M 6e:3a:20:52:4f:4f 1:0:0:0:0:0 5420 14:

although I think that was coincidental. Subsequent pings show nothing.

> Does the hardware address of B get into A's arp cache when you issue a ping?

Yeah. `arp -an` shows:

? (<B's IP ADDRESS>) at <incomplete> on eth0

Likewise, the arp stuff is in B's arp cache, also showing <incomplete>.

> I don't really have a clue what your problem is, I'm just poking for more
> info that might possibly shed some light on the issue.  Donald might just
> know everything.  He frequently seems to.

Thanks for asking the questions, just the same. (P.S. I agree with you about
Donald. :)

Peter Green
Gospel Communications Network, SysAdmin
 | To unsubscribe, send mail to, and within the
 |  body of the mail, include only the text:
 |   unsubscribe this-list-name
 | You will be unsubscribed as speedily as possible.