[483] in linux-net channel archive
plip progress
daemon@ATHENA.MIT.EDU (Ken Estes)
Wed Jun 14 01:37:41 1995
Date: Wed, 14 Jun 95 00:45:57 EDT
From: m-ke0082@SPARKY.CS.NYU.EDU (Ken Estes)
To: linux-net@vger.rutgers.edu
I had a strange plip thought. Since plip appears to run ethernet,
could I wire together a bunch of plip cables and run several (3-10)
machines on a cheap network? I assume that all the length
requirements are meet but that should not be too hard since printer
cables are not that long. Well I can not get two working so that
project will have to wait, but is it feasible?
I am making good progress on my plip problems. I have found that my
main problem was the way that the parallel port was configured. I did
not think nimbus was the problem since nimbus is a new machine. I
assumed my problem had to be with the older "outdated" cirrus. It was
some observant comments that put me on the right path. My parallel
port is on the motherboard, so it is not a settable card with jumpers
(well mabe it is, I have not opened the case) I think of it as
"standard PC output" of course I now know that even this is not
standard. There is a menu that I can access at boot time which I have
always ignored. I would have never thought that there was anything
relating to the parallel port in this menu. I found some strange sub
menu deep in the "advanced" section, which has ways to set the
parallel port (unidirectional, bidirectional, enhanced. Enhanced just
hangs linux but both uni and bi directional work). I can also pick
the address and IRQ and I can even disable the IRQ. Obviously the fix
was to set this so that it matched what linux said it found already.
This made a connection between nimbus and cirrus.
However the connection is asymmetric. If nimbus pings cirrus I get all
packets responding in 13ms and if I ping the other way I loose over
80% of the packets and it takes 16ms. I assume the problem is at the
nimbus end (why not everything else seems to be). I have tried all
combinations of settings for the parallel port and am again out of
ideas.
Here is an output
of my log /usr/adm/messages
Jun 13 23:19:41 Nimbus kernel: plip1: transmit timeout(2,87)
Jun 13 23:20:12 Nimbus last message repeated 24 times
Jun 13 23:21:13 Nimbus last message repeated 49 times
Jun 13 23:22:14 Nimbus last message repeated 52 times
Jun 13 23:39:44 Nimbus kernel: plip1: transmit timeout(2,87)
Jun 13 23:39:53 Nimbus last message repeated 7 times
Jun 14 00:05:35 Nimbus kernel: keyboard error
Jun 14 00:06:58 Nimbus kernel: keyboard error
why all the time outs? I get only 1 or two on the other machine.
Since It was so helpful last time I give some output from my machines
Nimbus:/home/ken# ifconfig
lo Link encap:Local Loopback
inet addr:127.0.0.1 Bcast:127.255.255.255 Mask:255.0.0.0
UP BROADCAST LOOPBACK RUNNING MTU:2000 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0
TX packets:30 errors:0 dropped:0 overruns:0
plip1 Link encap:10Mbps Ethernet HWaddr FC:FC:80:FD:9A:20
inet addr:128.253.154.32 P-t-P:128.253.154.33 Mask:255.255.0.0
UP POINTOPOINT RUNNING MTU:1500 Metric:1
RX packets:176 errors:0 dropped:0 overruns:0
TX packets:42 errors:134 dropped:0 overruns:0
Interrupt:7 Base address:0x378
Nimbus:/home/ken# route
Kernel routing table
Destination Gateway Genmask Flags MSS Window Use Iface
Cirrus.cloudbas * 255.255.255.255 UH 1436 0 174 plip1
loopback * 255.0.0.0 U 1936 0 30 lo
Nimbus:/home/ken#
Nimbus:/home/ken# PING Cirrus.cloudbase.edu (128.253.154.33): 56 data bytes
64 bytes from 128.253.154.33: icmp_seq=0 ttl=255 time=27.7 ms
64 bytes from 128.253.154.33: icmp_seq=1 ttl=255 time=13.8 ms
64 bytes from 128.253.154.33: icmp_seq=2 ttl=255 time=13.6 ms
64 bytes from 128.253.154.33: icmp_seq=3 ttl=255 time=13.8 ms
64 bytes from 128.253.154.33: icmp_seq=4 ttl=255 time=13.6 ms
64 bytes from 128.253.154.33: icmp_seq=5 ttl=255 time=13.7 ms
64 bytes from 128.253.154.33: icmp_seq=6 ttl=255 time=13.7 ms
64 bytes from 128.253.154.33: icmp_seq=7 ttl=255 time=13.5 ms
64 bytes from 128.253.154.33: icmp_seq=8 ttl=255 time=13.7 ms
--- Cirrus.cloudbase.edu ping statistics ---
9 packets transmitted, 9 packets received, 0% packet loss
round-trip min/avg/max = 13.5/15.2/27.7 ms
Nimbus:/home/ken#
------------
from cirrus
------------
Kernel routing table
Destination Gateway Genmask Flags MSS Window Use Iface
Nimbus.cloudbas * 255.255.255.255 UH 1436 0 196 plip1
loopback * 255.0.0.0 U 1936 0 66 lo
lo Link encap:Local Loopback
inet addr:127.0.0.1 Bcast:127.255.255.255 Mask:255.0.0.0
UP BROADCAST LOOPBACK RUNNING MTU:2000 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0
TX packets:54 errors:0 dropped:0 overruns:0
plip1 Link encap:10Mbps Ethernet HWaddr FC:FC:80:FD:9A:21
inet addr:128.253.154.33 P-t-P:128.253.154.32 Mask:255.255.0.0
UP POINTOPOINT RUNNING MTU:1500 Metric:1
RX packets:785 errors:0 dropped:2 overruns:0
TX packets:1190 errors:19 dropped:0 overruns:0
Interrupt:7 Base address:0x378
PING Nimbus.cloudbase.edu (128.253.154.32): 56 data bytes
64 bytes from 128.253.154.32: icmp_seq=0 ttl=255 time=16.7 ms
64 bytes from 128.253.154.32: icmp_seq=6 ttl=255 time=16.7 ms
64 bytes from 128.253.154.32: icmp_seq=11 ttl=255 time=16.7 ms
64 bytes from 128.253.154.32: icmp_seq=16 ttl=255 time=16.9 ms
64 bytes from
--- Nimbus.cloudbase.edu ping statistics ---
22 packets transmitted, 5 packets received, 77% packet loss
round-trip min/avg/max = 16.7/16.8/17.2 ms
