Using an NTS instead of the local serial device ?

Using an NTS instead of the local serial device ?

[wotuzu17]

Hi folks,


I just successfully set up a basic ppp link between 2 Ubuntu 7.10 machines.



The commands look like this:


me@machine1 $ pppd -detach persist lock proxyarp 192.168.10.1:192.168.10.2
/dev/ttyS0 38400 &


me@machine2 $ pppd -detach persist lock defaultroute
192.168.10.2:192.168.10.1 /dev/ttyS0 38400 &


I wonder whether it is posible to use a serial port of an NTS for
communiction instead of the local serial device /dev/ttyS0 ? I own a
Lantronix ETS8P, which is a 8-port Network Terminal Server.


I tried

me@machine1 $ pppd -detach persist lock proxyarp 192.168.10.1:192.168.10.2
ip.of.nts:tcpport 38400 &


without success. 

As I am new to Linux in general, maybe somebody can give me a hint.


Thanks
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Re: Using an NTS instead of the local serial device ?

[cfowler]

I do not think PPPD can connect to a terminal via the method you tried.
What you need to do is load the Lantronix virtual serial port software on
both servers and setup a pseudo serial port.  Tell pppd to use that instead.
It should work but why not just use the network and create PPPD over an ssh 
ssh tunnel instead of using a terminal server to begin with.  Why
are you using a termianl server anyway?  Can't the machines communicate over
the network?

Also look at OpenVPN and Vtun.  You can create pppd links using
pseudos that way too.

On Fri, Dec 28, 2007 at 02:32:35PM -0800, wotuzu17 wrote:
> 
> Hi folks,
> 
> 
> I just successfully set up a basic ppp link between 2 Ubuntu 7.10 machines.
> 
> 
> 
> The commands look like this:
> 
> 
> me@machine1 $ pppd -detach persist lock proxyarp 192.168.10.1:192.168.10.2
> /dev/ttyS0 38400 &
> 
> 
> me@machine2 $ pppd -detach persist lock defaultroute
> 192.168.10.2:192.168.10.1 /dev/ttyS0 38400 &
> 
> 
> I wonder whether it is posible to use a serial port of an NTS for
> communiction instead of the local serial device /dev/ttyS0 ? I own a
> Lantronix ETS8P, which is a 8-port Network Terminal Server.
> 
> 
> I tried
> 
> me@machine1 $ pppd -detach persist lock proxyarp 192.168.10.1:192.168.10.2
> ip.of.nts:tcpport 38400 &
> 
> 
> without success. 
> 
> As I am new to Linux in general, maybe somebody can give me a hint.
> 
> 
> Thanks
> -- 
> View this message in context: http://www.nabble.com/Using-an-NTS-instead-of-the-local-serial-device---tp14532384p14532384.html
> Sent from the linux-ppp mailing list archive at Nabble.com.
> 
> -
> To unsubscribe from this list: send the line "unsubscribe linux-ppp" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: Using an NTS instead of the local serial device ?

[Paul Mackerras]

wotuzu17 writes:

> I wonder whether it is posible to use a serial port of an NTS for
> communiction instead of the local serial device /dev/ttyS0 ? I own a
> Lantronix ETS8P, which is a 8-port Network Terminal Server.
> 
> 
> I tried
> 
> me@machine1 $ pppd -detach persist lock proxyarp 192.168.10.1:192.168.10.2
> ip.of.nts:tcpport 38400 &

It *might* be possible to get pppd to talk to the terminal server
using the -socket option, but it would depend on what protocol the
terminal server talks across the network.  Can you give us any details
on that protocol?

Paul.

Re: Using an NTS instead of the local serial device ?

[wotuzu17]

After browsing the support sites of Lantronix, I think I found the software I
need:

The  rtelpd  daemon  process  is used to provide access to
serial or parallel ports on a terminal  server.   A  named
pipe  is used as the actual interface to host based appli-
cations.  These applications  can  then  communicate  with
equipment  attached  to  the  server  as if it was locally
attached to the unix host.

I can create a /dev/somepipename device with that tool.


I need this rather unconventional method because we have several remote
sites that are connected to the center via public digital lines (64k).
Multiplexer on each end offer up to 16 transparent serial RS232 ports. Via
the ppp link we get access to the network in the center- it's slow but
sufficient for our application.

The NTS is only needed in the center because it offers 8 ports. I find this
more elegant than upgrading the Ubuntu- Server with additional serial ports.
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Re: Using an NTS instead of the local serial device ?

[wotuzu17]

If there was a -socket option, I'd like to try. But I can't find a -socket
option neither in the man pages nor in other documentation about pppd. 

# pppd: unrecognized option '-socket'

Here at home I have a Suse 10.1 linux with pppd version 2.4.3 installed. 

The serial ports on the Lantronix are easily accessable- e.g.
# telnet 192.168.0.1 2003

will write everything that's being typed to physical port 3, and everything
that is being receveid on that port 2 is displayed in the telnet window



Paul Mackerras wrote:
> 
> wotuzu17 writes:
> 
>> I wonder whether it is posible to use a serial port of an NTS for
>> communiction instead of the local serial device /dev/ttyS0 ? I own a
>> Lantronix ETS8P, which is a 8-port Network Terminal Server.
>> 
>> 
>> I tried
>> 
>> me@machine1 $ pppd -detach persist lock proxyarp
>> 192.168.10.1:192.168.10.2
>> ip.of.nts:tcpport 38400 &
> 
> It *might* be possible to get pppd to talk to the terminal server
> using the -socket option, but it would depend on what protocol the
> terminal server talks across the network.  Can you give us any details
> on that protocol?
> 
> Paul.
> -
> To unsubscribe from this list: send the line "unsubscribe linux-ppp" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 
> 

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Re: Using an NTS instead of the local serial device ?

[cfowler]

On Fri, Dec 28, 2007 at 04:41:04PM -0800, wotuzu17 wrote:
> 
> If there was a -socket option, I'd like to try. But I can't find a -socket
> option neither in the man pages nor in other documentation about pppd. 
> 
> # pppd: unrecognized option '-socket'
> 
> Here at home I have a Suse 10.1 linux with pppd version 2.4.3 installed. 
> 
> The serial ports on the Lantronix are easily accessable- e.g.
> # telnet 192.168.0.1 2003
> 

I do not think my version of pppd supports that either.  What you need is the
software that will create link a pseudo tty in each system to the terminal
server and then you can run pppd on each side.

http://demo.opsdc.com/atlpm/ttyd2.pl

I wrote that for a friend to map some pseudos on a SUN box to another
terminal server.  It may need some tweaks but should map a pseudo 
on Linux to a port on the TS.

Re: Using an NTS instead of the local serial device ?

[Paul Mackerras]

wotuzu17 writes:

> If there was a -socket option, I'd like to try. But I can't find a -socket
> option neither in the man pages nor in other documentation about pppd. 
> 
> # pppd: unrecognized option '-socket'

Sorry, it's "socket" (no dash) and it takes an argument which is
host:port.  However, if the Lantronix really does the telnet protocol
then it won't work properly since telnet interprets the 0xff character
and CR (0x0d) characters specially.

If you can put the terminal server into a mode where everything
received on the socket is sent to the serial port, without
interpretation, and everything from the serial port is sent on the
socket, without modification, then you could use it with the pppd
"socket" option.

Paul.

Re: Using an NTS instead of the local serial device ?

[James Carlson]

Paul Mackerras writes:
> wotuzu17 writes:
> 
> > If there was a -socket option, I'd like to try. But I can't find a -socket
> > option neither in the man pages nor in other documentation about pppd. 
> > 
> > # pppd: unrecognized option '-socket'
> 
> Sorry, it's "socket" (no dash) and it takes an argument which is
> host:port.  However, if the Lantronix really does the telnet protocol
> then it won't work properly since telnet interprets the 0xff character
> and CR (0x0d) characters specially.

Lantronix devices support both.  You connect to 2000+n to get TELNET
protocol (with the 0xff escapes), and 3000+n for a raw TCP connection.

So, for port 1, use this in pppd:

	socket ip-address:3001

(Most other terminal servers have similar features.  For example, the
equivalent ranges on Annexes are 5000+n for TELNET and 7000+n for raw
TCP.)

I would advise the original poster to avoid reverse telnet.  It may
work with some applications, but it's a frightening bit of hackery
that (at least in my experience) often fails in strange ways.

-- 
James Carlson         42.703N 71.076W         <carlsonj@workingcode.com>