[lug] Serial Line Direct Connection

[Daniel Webb]

I have had an old (1997 or so) laptop running PPP over serial at around 10
KB/s, and I think it was more like 30 KB/s using PLIP.  I loaded Debian
over PLIP using a special PLIP installer.  I don't recommend it unless
there's no other choice.  It will probably take a little (or a lot) time
to get working.  I have been much happier since I bought an SMC PCMCIA
ethernet card for $80 or so.

By the way, I had no problem running RS232 100 ft at full port speed (115
kb/s?), despite everyone saying that can't be done.  I was running it over
cat5 cable, using only 3 wires.

These are the notes I wrote to myself about setting up PLIP, but I seem to
have misplaced the serial port notes:


Connecting to a laptop via parallel port:
  parallel port stuff must be compiled in the kernel as modules
  plip driver must be in the kernel as a module
  BIOS must set up parallel port
  echo 7 > /proc/parport/0/irq
    ... if the parallel port irq is 7
  modprobe plip
  add laptop IP to /etc/hosts
  /etc/hosts.allow should have lines:
    portmap: 192.168.1.1
    ... replace with your IP, but IP MUST be a number!
  set /etc/exports to the directory you want.  Also, be sure
    and use the no_root_squash and no_subtree_check options.
  make sure NFS is running:
    rpcinfo -p
  Bring up plip interace:
    ifconfig plip0 robust pointopoint laptop netmask 255.255.255.0 up
  Turn on IP forwarding
    echo 1 > /proc/sys/net/ipv4/ip_forward
  Starting ipchains for masquerading on the host (unsecure way)
    ipchains -P forward MASQ



On Sat, 20 Apr 2002, John Karns wrote:

> On 19 Apr 2002, Nate Duehr said:
>
> > What's the maximum speed the high speed parallel ports can run?
>
> Theoretical, I can't say - it depends on your particular harware and
> configuration: ECP, and the two or three others that exist.  Although I
> seem to recall having to fiddle a bit with my port setup, as the PLIP
> driver didn't seem to like all cfg's.  In particular, IIRC it didn't like
> ECP.  It's been about a year since I used it, so I'm a bit fuzzy on the
> details.
>
> Practically, I was getting between 3 and 4 kB / sec.
>
> ----------------------------------------------------------------
> John Karns                                        jkarns at csd.net
>
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