connect two redhat6.0 PC using null-modem ppp?

connect two redhat6.0 PC using null-modem ppp?

Post by iceri.. » Sun, 01 Oct 2000 04:00:00



Hi,all:
  My os is redhat6.0,I can connect them well using modem by ppp.But
when I use null-modem cable connect them,then type the following:

  pppd -detach crtscts lock 192.168.0.1:192.168.0.1 /dev/ttyS0 19200 &

  They run ok,but The ppp0 doesn't run,of course,I can't ping through.
  If I have use the wrong 9 ping serial cable? Could someone help me!
                  your sincerely rosely

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connect two redhat6.0 PC using null-modem ppp?

Post by Tim Hayne » Sun, 01 Oct 2000 04:00:00



>   My os is redhat6.0,I can connect them well using modem by ppp.But
> when I use null-modem cable connect them,then type the following:

>   pppd -detach crtscts lock 192.168.0.1:192.168.0.1 /dev/ttyS0 19200 &

>   They run ok,but The ppp0 doesn't run,of course,I can't ping through.
>   If I have use the wrong 9 ping serial cable? Could someone help me!

Can you connect across with either minicom, cu or just plain ol' cat?

~Tim
--

with their secret weapon.                       | http://piglet.is.dreaming.org

 
 
 

connect two redhat6.0 PC using null-modem ppp?

Post by David Efflan » Mon, 02 Oct 2000 04:00:00



>  My os is redhat6.0,I can connect them well using modem by ppp.But
>when I use null-modem cable connect them,then type the following:

>  pppd -detach crtscts lock 192.168.0.1:192.168.0.1 /dev/ttyS0 19200 &

>  They run ok,but The ppp0 doesn't run,of course,I can't ping through.
>  If I have use the wrong 9 ping serial cable? Could someone help me!
>                  your sincerely rosely

What do ifconfig and 'route -n' show after you bring the connection up?

Any LapLink/Interlink/null modem cable should work with 9 or 25 pins.  But
you cannot use the same IP for both local and remote.  Try using different
IPs, but make sure you swap which is local on the remote box (like
192.168.0.1:192.168.0.2 on one box and 192.168.0.2:192.168.0.1 on the
other.

The first pppd should be started in 'passive' mode, so it will wait for a
connection by the other one.  Otherwise the first pppd you start will not
find anything to connect to and may die.

Note that if either box has old 8250 UART, you my have trouble
communicating faster than 9600.  If they are both 16550A UART, you should
have no trouble bumping up to 115200.

--

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http://hammer.prohosting.com/~cgi-wiz/  http://cgi-help.virtualave.net/

 
 
 

connect two redhat6.0 PC using null-modem ppp?

Post by Clifford Kit » Mon, 02 Oct 2000 04:00:00



> My os is redhat6.0,I can connect them well using modem by ppp.But
> when I use null-modem cable connect them,then type the following:
>   pppd -detach crtscts lock 192.168.0.1:192.168.0.1 /dev/ttyS0 19200 &
> They run ok,but The ppp0 doesn't run,of course,I can't ping through.
> If I have use the wrong 9 ping serial cable? Could someone help me!

For a full nullmodem cable try

Computer 1
/usr/sbin/pppd /dev/ttyS1 debug crtscts local 115200 192.168.1.1:192.168.1.2 &
Computer 2
/usr/sbin/pppd /dev/ttyS1 debug passive crtscts local 115200 &

For a 3-wire nullmodem cable try the same commands but replace crtscts
with nocrtscts and add xonxoff.  You might also have to lower the speed.

You also could put a cheap NIC in each box and run a crossover cable
between them.  You wouldn't need PPP and it would be a lot faster.

--

/* The wealth of a nation is created by the productive labor of its
 * citizens. */

 
 
 

connect two redhat6.0 PC using null-modem ppp?

Post by iceri.. » Wed, 04 Oct 2000 15:30:52


Dear Clifford,Tim and David:
  Thank all of you very much from my heart,what you say really helped
me!
  It really is that I miss "passive" in the second computer.
  Thank you again!
                 love you's iceriver



> > My os is redhat6.0,I can connect them well using modem by ppp.But
> > when I use null-modem cable connect them,then type the following:

> >   pppd -detach crtscts lock 192.168.0.1:192.168.0.1 /dev/ttyS0
19200 &

> > They run ok,but The ppp0 doesn't run,of course,I can't ping through.
> > If I have use the wrong 9 ping serial cable? Could someone help me!

> For a full nullmodem cable try

> Computer 1
> /usr/sbin/pppd /dev/ttyS1 debug crtscts local 115200

192.168.1.1:192.168.1.2 &

> Computer 2
> /usr/sbin/pppd /dev/ttyS1 debug passive crtscts local 115200 &

> For a 3-wire nullmodem cable try the same commands but replace crtscts
> with nocrtscts and add xonxoff.  You might also have to lower the
speed.

> You also could put a cheap NIC in each box and run a crossover cable
> between them.  You wouldn't need PPP and it would be a lot faster.

> --

> /* The wealth of a nation is created by the productive labor of its
>  * citizens. */

Sent via Deja.com http://www.deja.com/
Before you buy.
 
 
 

connect two redhat6.0 PC using null-modem ppp?

Post by neil dudlesto » Wed, 04 Oct 2000 04:00:00



> Hi,all:
>   My os is redhat6.0,I can connect them well using modem by ppp.But
> when I use null-modem cable connect them,then type the following:

>   pppd -detach crtscts lock 192.168.0.1:192.168.0.1 /dev/ttyS0 19200 &

>   They run ok,but The ppp0 doesn't run,of course,I can't ping through.
>   If I have use the wrong 9 ping serial cable? Could someone help me!
>                   your sincerely rosely

> Sent via Deja.com http://www.deja.com/
> Before you buy.

You have the same IP address for both ends 192.168.0.1. Change one end
and reverse it on the other machine.
I use: pppd -detach crtscts lock debug defaultroute 172.16.0.1:172.16.0.2
/dev/cua0 38400 &

then reverse the ip address on the other machine. The debug will show the
LCP negotiation (and more ).

use /dev/cua0 not ttyS0 which has a mini getty on it so ppp cannot start

---
Neil Dudleston

 
 
 

connect two redhat6.0 PC using null-modem ppp?

Post by James Carlso » Thu, 05 Oct 2000 04:00:00



> You have the same IP address for both ends 192.168.0.1. Change one end
> and reverse it on the other machine.
> I use: pppd -detach crtscts lock debug defaultroute 172.16.0.1:172.16.0.2
> /dev/cua0 38400 &

> then reverse the ip address on the other machine. The debug will show the
> LCP negotiation (and more ).

You don't need to specify the IP addresses on both PPP sessions.
Specifying "172.16.0.1:" on one side and "172.16.0.2:" on the other is
the simplest configuration.  You can also do "172.16.0.1:172.16.0.2"
on one side and *no* addresses on the other.

Quote:> use /dev/cua0 not ttyS0 which has a mini getty on it so ppp cannot start

I don't think that's right for Linux, but I'm sure a Linux expert will
follow up with more.  I think "cua" is obsolescent on Linux and ttySx
is the right way to go.

In any event, getty should never be running on a cua port on a Unix
system.  cua is generally for dial-out, not dial-in.  (Unless, well,
Linux is very weird here.  It's chown is bizarre, so I guess it's not
beyond the pale ...)

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