RE: [9fans] stats: ethererr

[Dean Ash <Dean.Ash@Ingenix.com>]

cool, now I have a beginning. driver I don't know about that one. P9
recognizes the card (I'm told it's a 3COM 905, have to verify that). Card is
a distinct possibility, linux didn't work with it either, which I'd say is
weird with a 3COM card. Wire, maybe the one coming out of the computer is
bad but I'm almost 80% sure the port that connects P9 to the rest of the
network is bad. Well I'll have to do some futzing around this weekend if
time permits. Thanks for the help. Great website by the way Boyd. I just got
done going through it, very humorous.

Dean

-----Original Message-----
From: Boyd Roberts [mailto:boyd@fr.inter.net]
Sent: Thursday, August 16, 2001 3:58 PM
To: 9fans@cse.psu.edu
Subject: Re: [9fans] stats: ethererr


i shall try and resurrect my badly banged around neurons after my
göteborg trip, so here goes:

> >> - crc means your packets are trashed when they get received

each ethernet packet has a 16 bit crc.  it 'ensures' that it got
received ok, but that's a lie.  talk to Sun about UDP checksums...

so on the rx and tx sides the crc's have to be done right.

> Received by whom or what? the DHCP server? or my p9 machine? if it's my
> machine doing the trashing is there a way to fix it? if they're getting
> trashed by the dhcp server what can I do to fix that, especially since I
> have to go through a network admin =)

this has nothing to do with DHCP.  these is the physical bits on the wire
[ethernet].
DHCP is a coupla layers up.  you have wire/card/driver problems.

the framing is to do with the pre/post-able bits that are there to ensure
collisions based on speed of light / velocity factor propagation.  well,
maybe i really mean that the coax/utp needs to be modulated in the right
way at the right time.

> The other stuff was greek to me. Tx, rx? what is that apparently I need to
> read a book on basic networking and ethernet cards.

tx = transmit
rx = receive

de f/vk2bhr ...