6. Activate the PLIP link.

Finally, these are the commands, that must be executed with root rights, that activate the PLIP interface (of course the cable must be already plugged correctly).

NOTE: If something unexpected happens, please doublecheck the cable and the spelling of the commands. If you followed the istructions correctly but the are still errors, read the FAQ paragraph, a lot of answers are already available.

First of all confirm that there is no lp device present:

# cat /proc/devices

You mustn't see any reference to lp like this:

 6 lp

If you see it, please remove (temporanely) the lp device before going on, if PLIP works then you can try it with lp later. To remove the lp device you'll have to use the rmmod if it's a module; if instead it's built in the kernel, you'll need to recompile the kernel with lp as a module (a much wiser idea).

Again I use the name one and two, as example. On one you'll have to do the following steps.

If you don't have the module automounter daemon and you compiled PLIP as a module, you must mount it:

# insmod plip

NOTE: if your parallel port is on an IRQ different from 7 and/or is on a IO Address different from 0x378, then you'll have to tell it to insmod. Find your real IRQ and IO Address (the DOS command MSD is likely to be ok, but don't trust it too much) and write something like this:

# insmod plip io=0x278 irq=5

Usually IRQ is 7 or 5, while IO Address is 0x378, 0x278 or 0x3bc. It is important that you check that the address and IRQ match the hardware settings (jumpers on old boards, BIOS on modern motherboards).

If you are paranoic check that the module has been loaded with:

  # lsmod

Module:        #pages:  Used by:
plip               3            0

Take notice of the interface name (plip0, plip1, and so on; for more details read the kernel messages chapter above), then set up the PLIP interface:

# ifconfig plip1 one pointopoint two up

NOTE: if your parallel port is on an IRQ different from 7 and/or is on a IO Address different from 0x378, then you'll have to tell it to ifconfig. Use the same IRQ and IO Address reported by the kernel messages and write something like this:

# ifconfig plip1 irq 7
# ifconfig plip1 io_addr 0x3bc

Usually IRQ is 7 or 5, while IO Address is 0x378, 0x278 or 0x3bc.

Now check that it worked...

# ifconfig



 .....
 .....
 plip1     Link encap:10Mbps Ethernet  HWaddr FC:FC:C8:00:00:01
           inet addr:200.0.0.1  P-t-P:200.0.0.2  Mask:255.255.255.0
           UP POINTOPOINT RUNNING NOARP  MTU:1500  Metric:1
           RX packets:0 errors:0 dropped:0 overruns:0
           TX packets:0 errors:0 dropped:0 overruns:0
           Interrupt:7 Base address:0x378 

Add the route to two...

# route add two plip1

And, if you want also the NFS for two:

# rpc.portmap
# rpc.mountd
# rpc.nfsd

On "two" the commands are the same, but you must write one instead of two and vice versa.

One of your machines is likely to have only the PLIP connection, if this is true and that machine is two, you may also type:

# route add default gw one

on that machine. In my example above, two is a laptop with only a PLIP connection with one, so I type the above line on two.

Finally check with a

# ping two

from one and a

# ping one 

from two to see that all is working.

Of course you may want to have all these commands automatically done by a script or at boot time. You must only create a script that execute these commands: now you may invoke it as root when you need, or you may add a command (in /etc/rc.d/rc.inet2) that calls it at boot time.

To tune your PLIP, you can use the plipconfig command, see the man page for more informations.

To shutdown PLIP, you need only to do:

# ifconfig plip1 down

which removes also the route entries. If you don't have the automounter daemon, then remove also the module:

# rmmod plip