Subject: ftp transfer speed anomaly
To: None <current-users@netbsd.org>
From: Space Case <wormey@eskimo.com>
List: current-users
Date: 12/18/1998 21:52:45
Greg Oster took a look at my data dump; here's his analysis. It's looking
more and more (to me, at least) that it's a problem with the ethernet card.
Unfortunately, I cannot get the box to see the other ethernet card that I
have (an ISA NE-2000 clone). :-(
~Steve
--- Forwarded mail from Greg Oster <oster@cs.usask.ca>
>From oster@cs.usask.ca Fri Dec 18 19:47:28 1998
Message-Id: <199812190352.VAA18194@cs.usask.ca>
To: wormey@eskimo.com (Space Case)
Subject: Re: ftp transfer speed anomaly
In-reply-to: Your message of "Fri, 18 Dec 1998 17:52:27 PST."
<199812190152.RAA07179@eskimo.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Date: Fri, 18 Dec 1998 21:50:27 -0600
From: Greg Oster <oster@cs.usask.ca>
Space Case writes:
> On Dec 18, 1:58pm, Greg Oster wrote:
> >Space Case writes:
> >> Here's an excerpt from the tcpdump (the whole dump is available at
> >> ftp://ftp.eskimo.com/u/w/wormey/dump2.out if anybody's interested in it).
> >
> >Can you send me a partial trace, where you run:
> > tcpdump -s 100 -x host jared and host gate2
>
> The dump mentioned above on eskimo is the raw data, about 2300 packets
> worth.
Sorry.. hadn't realized it had packet contents :-) (actually didn't even look
at it..)
> Feel free to dig around in it.
Was about to say "I couldn't find anything", but....
tcpdump -v -s 1600 -x -r dump2.out | grep "sum" | grep -v "tcp sum ok" | grep
-v "udp"
gives me:
22:34:42.737141 truncated-ip - 16164 bytes missing!171.63.192.168 > 0.4.192.168: (frag 1500:17664@17456) (ttl 64, bad cksum 8006!, optlen=-20 EOL--21)
22:34:43.655419 0.0.192.168.tcpmux > 0.4.192.168.1158: SFRP 1313292:1314768(1476) ack 1098727584 win 20504 (DF) (ttl 128, id 54918, bad cksum 9d3f!)
22:34:45.436636 truncated-ip - 16164 bytes missing!114.63.192.168 > 0.4.192.168: (frag 1500:17664@3128) (ttl 64, bad cksum 8006!, optlen=-20 EOL--21)
22:35:03.636626 225.62.192.168 > 0.4.192.168: ip-proto-0 1480 (DF) [ttl 0] (id 37511, bad cksum 8006!)
22:35:04.636535 183.62.192.168 > 0.4.192.168: ip-proto-0 1480 (DF) [ttl 0] (id 48263, bad cksum 8006!)
22:35:06.036256 truncated-ip - 16164 bytes missing!131.62.192.168 > 0.4.192.168: (frag 1500:17664@33848+) (ttl 64, bad cksum 8006!, optlen=-20 EOL--21)
22:35:51.030432 0.0.192.168.tcpmux > 0.4.192.168.1158: SFRP 1313299:1314775(1476) ack 3368370336 win 20496 (DF) (ttl 128, id 45960, bad cksum c03d!)
Not sure what's happening, but there looks like there's some serious hosage
going on somewhere... "0.0.192.168.tcpmux > 0.4.192.168.1158" looks suspicious.
..
22:34:43.655419 0.0.192.168.tcpmux > 0.4.192.168.1158: SFRP 1313292:1314768(1476
) ack 1098727584 win 20504 (DF) (ttl 128, id 54918, bad cksum 9d3f!)
4500 05dc d686 4000 8006 9d3f 0000 c0a8
^^^^
THIS IS WRONG! :-(
0004 c0a8 0001 0486 0014 0a0c 417d 40a0
191f 5018 2238 d9fb 0000 4a42 4b3f 4738
4b3c 5442 5743
22:35:04.636535 183.62.192.168 > 0.4.192.168: ip-proto-0 1480 (DF) [ttl 0] (id 4
8263, bad cksum 8006!)
4500 05dc bc87 4000 0000 8006 b73e c0a8
^^^^
THIS IS WRONG TOO! :-(
0004 c0a8 0001 0486 0014 0a0f e68d 40a0
191f 5010 2238 e4a5 0000 a03f 7c72 8785
fe00 0cd1 0385
Not sure, but it looks like this could just be due to Ethernet grief... (as
others have suggested)...
(Feel free to ship this to current-users, if you'd like...)
Later...
Greg Oster
--- End of forwarded message from Greg Oster <oster@cs.usask.ca>
--
Steve Allen - wormey@eskimo.com http://www.eskimo.com/~wormey/ ICQ 6709819
Faith is the quality that enables you to eat blackberry jam on a picnic
without looking to see whether the seeds move.
Contrary to popular belief, Unix is user friendly.
It just happens to be selective about who it makes friends with.
-Kyle Hearn <kyle@intex.net>
It is impossible to travel faster than light, and certainly not
desirable, as one's hat keeps blowing off.
-- Woody Allen