2.2.0 breaks telnet to old SysV R3 machine

Cord Seele (Cord.Seele@linmpi.mpg.de)
Thu, 28 Jan 1999 14:19:30 +0100

After upgrading to 2.2.0 I can't telnet/[rs]login to an old Motorola box
(VMEbus, SysV/68 R3) anymore. All other machines I have access to are fine.
But ping and ftp still work!
telnet: I do get `login:', but can't type in anything anymore. After the timeout
it says: Connection closed by foreign host.
rlogin: rcmd: wasp2.mpae.gwdg.de: Address already in use

Here are two tcpdumps (2.0.36 is fine, 2.2.0 isn't):

2.0.36:
13:30:35.067420 pSeele.mpae.gwdg.de.1026 > wasp1.rocketrange.no.telnet: S 1804116418:1804116418(0)
win 512 <mss 1460>
13:30:35.237420 wasp1.rocketrange.no.telnet > pSeele.mpae.gwdg.de.1026: S 2540321789:2540321789(0)
ack 1804116419 win 0 <mss 1456>
13:30:35.237420 pSeele.mpae.gwdg.de.1026 > wasp1.rocketrange.no.telnet: . ack 1 win 16060 (DF)
13:30:35.417420 wasp1.rocketrange.no.telnet > pSeele.mpae.gwdg.de.1026: . ack 1 win 5824
13:30:35.417420 pSeele.mpae.gwdg.de.1026 > wasp1.rocketrange.no.telnet: . 1:17(16) ack 1 win 16368
(DF)
13:30:35.417420 pSeele.mpae.gwdg.de.1026 > wasp1.rocketrange.no.telnet: P 17:28(11) ack 1 win
16368
(DF)
13:30:35.577420 wasp1.rocketrange.no.telnet > pSeele.mpae.gwdg.de.1026: . ack 28 win 5824
13:30:37.597420 wasp1.rocketrange.no.telnet > pSeele.mpae.gwdg.de.1026: P 1:47(46) ack 28 win 5824
13:30:37.597420 pSeele.mpae.gwdg.de.1026 > wasp1.rocketrange.no.telnet: P 28:31(3) ack 47 win
16368
(DF)
13:30:37.727420 wasp1.rocketrange.no.telnet > pSeele.mpae.gwdg.de.1026: P 47:81(34) ack 28 win
5824
13:30:37.737420 wasp1.rocketrange.no.telnet > pSeele.mpae.gwdg.de.1026: . ack 31 win 5824
13:30:37.737420 pSeele.mpae.gwdg.de.1026 > wasp1.rocketrange.no.telnet: . ack 81 win 16368 (DF)
13:30:38.197420 pSeele.mpae.gwdg.de.1026 > wasp1.rocketrange.no.telnet: P 28:31(3) ack 81 win
16368
(DF)
13:30:38.337420 wasp1.rocketrange.no.telnet > pSeele.mpae.gwdg.de.1026: . ack 31 win 5824
13:30:38.337420 pSeele.mpae.gwdg.de.1026 > wasp1.rocketrange.no.telnet: P 31:34(3) ack 81 win
16368
(DF)
13:30:38.457420 wasp1.rocketrange.no.telnet > pSeele.mpae.gwdg.de.1026: . ack 34 win 5824
13:30:38.457420 wasp1.rocketrange.no.telnet > pSeele.mpae.gwdg.de.1026: P 81:84(3) ack 34 win 5824
13:30:38.477420 pSeele.mpae.gwdg.de.1026 > wasp1.rocketrange.no.telnet: . ack 84 win 16368 (DF)

2.2.0:
13:12:11.073915 pSeele.mpae.gwdg.de.1204 > wasp1.rocketrange.no.telnet: S 1194794750:1194794750(0)
win 32120 <mss 1460,sackOK,timestamp 951104[|tcp]> (DF)
13:12:11.213806 wasp1.rocketrange.no.telnet > pSeele.mpae.gwdg.de.1204: S 2264428526:2264428526(0)
ack 1194794751 win 0 <mss 1456>
13:12:11.213892 pSeele.mpae.gwdg.de.1204 > wasp1.rocketrange.no.telnet: . ack 1 win 32120 (DF)
13:12:11.215397 pSeele.mpae.gwdg.de.1204 > wasp1.rocketrange.no.telnet: . ack 1 win 32120 (DF)
13:12:11.380293 wasp1.rocketrange.no.telnet > pSeele.mpae.gwdg.de.1204: . ack 1 win 5824
13:12:11.380407 pSeele.mpae.gwdg.de.1204 > wasp1.rocketrange.no.telnet: . ack 1 win 32120 (DF)
13:12:12.856998 pSeele.mpae.gwdg.de.1204 > wasp1.rocketrange.no.telnet: . ack 1 win 32120 (DF)
13:12:13.606424 wasp1.rocketrange.no.telnet > pSeele.mpae.gwdg.de.1204: P 1:47(46) ack 1 win 5824
13:12:13.606549 pSeele.mpae.gwdg.de.1204 > wasp1.rocketrange.no.telnet: . ack 47 win 32074 (DF)
13:12:13.732099 wasp1.rocketrange.no.telnet > pSeele.mpae.gwdg.de.1204: P 47:54(7) ack 1 win 5824
13:12:13.746963 pSeele.mpae.gwdg.de.1204 > wasp1.rocketrange.no.telnet: . ack 54 win 32120 (DF)
13:12:16.556989 pSeele.mpae.gwdg.de.1204 > wasp1.rocketrange.no.telnet: . ack 54 win 32120 (DF)
13:12:22.476991 pSeele.mpae.gwdg.de.1204 > wasp1.rocketrange.no.telnet: . ack 54 win 32120 (DF)
13:12:33.226987 pSeele.mpae.gwdg.de.1022 > wasp1.rocketrange.no.login: . ack 1985585136 win 32120
(DF)
13:12:34.316984 pSeele.mpae.gwdg.de.1204 > wasp1.rocketrange.no.telnet: . ack 54 win 32120 (DF)
13:12:43.116983 pSeele.mpae.gwdg.de.1202 > wasp1.rocketrange.no.telnet: . ack 2213248751 win 32120
(DF)
13:12:57.997001 pSeele.mpae.gwdg.de.1204 > wasp1.rocketrange.no.telnet: . ack 54 win 32120 (DF)
13:13:05.766989 pSeele.mpae.gwdg.de.1203 > wasp1.rocketrange.no.telnet: . ack 2233766693 win 32120
(DF)
13:13:11.703221 wasp1.rocketrange.no.telnet > pSeele.mpae.gwdg.de.1204: F 54:54(0) ack 1 win 5824
13:13:11.703329 pSeele.mpae.gwdg.de.1204 > wasp1.rocketrange.no.telnet: . ack 55 win 32119 (DF)
13:13:11.703373 pSeele.mpae.gwdg.de.1204 > wasp1.rocketrange.no.telnet: . ack 55 win 32119 (DF)

I don't understand much of this, but see differences already in the first package:
more options and win 32120 instead of win 512! Is this the problem?
Weird enough, telnet FROM the Motorola TO my Linux box with 2.2.0 works (when logging
in via a third host)!

I tried ping with various packet sizes: the Motorola box gives up at 16k while
other hosts on the same network still work.
I also reduced MAX_WINDOW to 8192 in tcp.h, but no effect.

This is as far as I could get without help. Where shall I look next?
I am happy to provide more info if needed.

Cord Seele

P.S.: Please, CC me directly, since I am not on the list. Thanks.

-- 
  Cord Seele				mailto:Cord.Seele@linmpi.mpg.de
  Max-Planck-Institut fuer Aeronomie
  Max-Planck-Str. 2			phone: (+49) 5556 979-340
D-37191 Katlenburg-Lindau, GERMANY	FAX:   (+49) 5556 979-240


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