PPP connexion throught TRB246 router

Networking Solutions
1

Hi,
I’m using a TRB246 with its RS232 terminal (Tx/Rx/GND) to setup a serial over IP connection on a datalogger. It’s works fine but, I’d like to create a PPP connection, like I used to use with a previous modem (an ercogener : it’s a fastrack/wavecom like for those who know). Beaucoup PPP allow me to pass TCP/IP on the serial connection, and so I’ll be able to display the datalogger webpage straight on a web browser.

In the TRB246 menus, there is no clue of a PPP settings. But, on the datasheet, it’s cleary says that there is PPP network protocol, and in SSH on the router, there is “pppd” installed. I think the virtual serial device is /dev/ttyS0 do I’ve tried a :
/usr/sbin/pppd /dev/ttyS0 115200 noauth local passive 192.168.1.1:192.168.1.4 nodetach

But the command stop after 2-3 sec without any error message.

Has anyone ever gone that far ? Any clue of what I should do to open a PPP connection on the datalogger ?

3

Hello,

I am currently working on your issue and will get back to you soon.

Regards,
M.

4

Hello there,

After further inspection, I will have to reach out to our R&D to ask about whether this functionality is possible with our devices. I will get back to you as soon as possible.

Regards,

M.

5

Hi MatasR,

ok thanks, let me know if I can provide you any information to help your team finding this.

bye

6

Hello,

Here’s the response from the RnD:

If the client wants to use the RS232 device, instead of using /dev/ttyS0 they could try /dev/rs232. To debug the application and monitor the service messages use ‘logread -f &’. For extra information you can add " debug" to the “/usr/sbin/pppd” command.

Regards,

M.

7

Hi,

I came back from holiday and I have to dive into this again.

So, here is the line I’m using in SSH ont the TRB246 to trying to connect the device :

/usr/sbin/pppd /dev/rs232 115200 noauth local passive nodetach debug

And in another windows on another ssh session, I made a logread -f &, as said, and get that :

root@TRB246:~# logread -f
936 Mon Aug 25 13:31:21 2025 daemon.notice pppd[17860]: pppd 2.4.9 started by root, uid 0
937 Mon Aug 25 13:31:21 2025 daemon.debug pppd[17860]: using channel 14
938 Mon Aug 25 13:31:21 2025 daemon.info pppd[17860]: Using interface ppp0
939 Mon Aug 25 13:31:21 2025 daemon.notice pppd[17860]: Connect: ppp0 ↔ /dev/rs232
940 Mon Aug 25 13:31:21 2025 daemon.debug pppd[17860]: sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x7e9a48f5>]
941 Mon Aug 25 13:31:24 2025 daemon.debug pppd[17860]: sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x7e9a48f5>]
942 Mon Aug 25 13:31:27 2025 daemon.debug pppd[17860]: sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x7e9a48f5>]
943 Mon Aug 25 13:31:30 2025 daemon.debug pppd[17860]: sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x7e9a48f5>]
944 Mon Aug 25 13:31:33 2025 daemon.debug pppd[17860]: sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x7e9a48f5>]
945 Mon Aug 25 13:31:36 2025 daemon.debug pppd[17860]: sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x7e9a48f5>]
946 Mon Aug 25 13:31:39 2025 daemon.debug pppd[17860]: sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x7e9a48f5>]
947 Mon Aug 25 13:31:42 2025 daemon.debug pppd[17860]: sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x7e9a48f5>]
948 Mon Aug 25 13:31:45 2025 daemon.debug pppd[17860]: sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x7e9a48f5>]
949 Mon Aug 25 13:31:48 2025 daemon.debug pppd[17860]: sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x7e9a48f5>]
950 Mon Aug 25 13:31:51 2025 daemon.warn pppd[17860]: LCP: timeout sending Config-Requests
951 Mon Aug 25 13:31:58 2025 daemon.debug pppd[17860]: rcvd [LCP ConfReq id=0x7 <asyncmap 0x0> <magic 0x421a40da> ]
952 Mon Aug 25 13:31:58 2025 daemon.debug pppd[17860]: sent [LCP ConfReq id=0x2 <asyncmap 0x0> <magic 0x81fc9a78>]
953 Mon Aug 25 13:31:58 2025 daemon.debug pppd[17860]: sent [LCP ConfRej id=0x7 ]
954 Mon Aug 25 13:32:01 2025 daemon.debug pppd[17860]: sent [LCP ConfReq id=0x2 <asyncmap 0x0> <magic 0x81fc9a78>]
955 Mon Aug 25 13:32:04 2025 daemon.debug pppd[17860]: rcvd [LCP ConfReq id=0x7 <asyncmap 0x0> <magic 0x421a40da> ]

There are multiple “sent” request without response, because the device take some time to startup. Then there is something come back “rcvd [LCP ConfReq id=0x7 <asyncmap 0x0> <magic 0x421a40da> ]” that I can’t interpret.

Any idea ?

Bye.

8

Hi again, to complete my previous message, I succeeded to establish a PPP link between my device and the router, I used this specific command :

/usr/sbin/pppd /dev/rs232 115200 noauth local passive persist holdoff 5 nodetach debug 192.168.1.1:192.168.1.4

And get that (with logread -f):

713 Thu Aug 28 06:31:39 2025 daemon.debug pppd[27274]: using channel 7
714 Thu Aug 28 06:31:39 2025 daemon.info pppd[27274]: Using interface ppp0
715 Thu Aug 28 06:31:39 2025 daemon.notice pppd[27274]: Connect: ppp0 ↔ /dev/rs232
716 Thu Aug 28 06:31:39 2025 daemon.debug pppd[27274]: sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0xf39795dc>]
717 Thu Aug 28 06:31:39 2025 daemon.debug pppd[27274]: rcvd [LCP ConfAck id=0x1 <asyncmap 0x0> <magic 0xf39795dc>]
718 Thu Aug 28 06:31:42 2025 daemon.debug pppd[27274]: sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0xf39795dc>]
719 Thu Aug 28 06:31:42 2025 daemon.debug pppd[27274]: rcvd [LCP ConfAck id=0x1 <asyncmap 0x0> <magic 0xf39795dc>]
720 Thu Aug 28 06:31:45 2025 daemon.debug pppd[27274]: rcvd [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0xfdac2fd> ]
721 Thu Aug 28 06:31:45 2025 daemon.debug pppd[27274]: sent [LCP ConfRej id=0x1 ]
722 Thu Aug 28 06:31:45 2025 daemon.debug pppd[27274]: rcvd [LCP ConfReq id=0x2 <asyncmap 0x0> <magic 0xfdac2fd>]
723 Thu Aug 28 06:31:45 2025 daemon.debug pppd[27274]: sent [LCP ConfAck id=0x2 <asyncmap 0x0> <magic 0xfdac2fd>]
724 Thu Aug 28 06:31:45 2025 daemon.debug pppd[27274]: sent [IPCP ConfReq id=0x1 <compress VJ 0f 01> <addr 192.168.1.1>]
725 Thu Aug 28 06:31:45 2025 daemon.debug pppd[27274]: sent [IPV6CP ConfReq id=0x1 ]
726 Thu Aug 28 06:31:45 2025 daemon.debug pppd[27274]: rcvd [LCP EchoReq id=0x0 magic=0xfdac2fd]
727 Thu Aug 28 06:31:45 2025 daemon.debug pppd[27274]: sent [LCP EchoRep id=0x0 magic=0xf39795dc]
728 Thu Aug 28 06:31:45 2025 daemon.debug pppd[27274]: rcvd [IPCP ConfReq id=0x1 <compress VJ 0f 01> <addr 0.0.0.0> <ms-dns1 0.0.0.0> <ms-dns2 0.0.0.0>]
729 Thu Aug 28 06:31:45 2025 daemon.debug pppd[27274]: sent [IPCP ConfRej id=0x1 <ms-dns1 0.0.0.0> <ms-dns2 0.0.0.0>]
730 Thu Aug 28 06:31:45 2025 daemon.debug pppd[27274]: rcvd [IPV6CP ConfReq id=0x1 ]
731 Thu Aug 28 06:31:45 2025 daemon.debug pppd[27274]: sent [IPV6CP ConfAck id=0x1 ]
732 Thu Aug 28 06:31:45 2025 daemon.debug pppd[27274]: rcvd [IPCP ConfAck id=0x1 <compress VJ 0f 01> <addr 192.168.1.1>]
733 Thu Aug 28 06:31:45 2025 daemon.debug pppd[27274]: rcvd [IPV6CP ConfAck id=0x1 ]
734 Thu Aug 28 06:31:45 2025 daemon.notice pppd[27274]: local LL address fe80::d1e2:e11b:2fea:be21
735 Thu Aug 28 06:31:45 2025 daemon.notice pppd[27274]: remote LL address fe80::2c49:de26:2af6:37d3
736 Thu Aug 28 06:31:45 2025 daemon.debug pppd[27274]: rcvd [IPCP ConfReq id=0x2 <compress VJ 0f 01> <addr 0.0.0.0>]
737 Thu Aug 28 06:31:45 2025 daemon.debug pppd[27274]: sent [IPCP ConfNak id=0x2 <addr 192.168.1.4>]
738 Thu Aug 28 06:31:45 2025 daemon.debug pppd[27274]: rcvd [IPCP ConfReq id=0x3 <compress VJ 0f 01> <addr 192.168.1.4>]
739 Thu Aug 28 06:31:45 2025 daemon.debug pppd[27274]: sent [IPCP ConfAck id=0x3 <compress VJ 0f 01> <addr 192.168.1.4>]
740 Thu Aug 28 06:31:45 2025 daemon.notice pppd[27274]: local IP address 192.168.1.1
741 Thu Aug 28 06:31:45 2025 daemon.notice pppd[27274]: remote IP address 192.168.1.4

And I can see a PPP connexion now existing on interface listed :

root@TRB246:~# ip -c a
[…]
17: ppp0: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UNKNOWN group default qlen 3
link/ppp
inet 192.168.1.1 peer 192.168.1.4/32 scope global ppp0
valid_lft forever preferred_lft forever
inet6 fe80::d1e2:e11b:2fea:be21 peer fe80::2c49:de26:2af6:37d3/128 scope link
valid_lft forever preferred_lft forever

But I’m not able to ping the device. After 30-60 seconds the PPP interface going “DOWN” and the IP I setting up disappear. What I’m missing here ? It seem I’m closer now.

9

Hey, last reply, in case anybody else would make similar configuration. You just need to create a service in /etc/init.d/ that continuously keep the ppd command up.
Here is mine :

#!/bin/sh /etc/rc.common
START=99STOP=10
USE_PROCD=1PROG=/usr/sbin/pppd
ARGS=“/dev/rs232 115200 noauth local passive persist holdoff 5 nodetach debug 192.168.1.1:192.168.1.4”
start_service() {
procd_open_instance
procd_set_param command $PROG $ARGS
procd_set_param respawn
procd_close_instance
}

Of course, you’ll need to adapt the “ARGS” field as required for you. For reminder, I’m using a TRB246.

Bye.

10

This topic was automatically closed 2 days after the last reply. New replies are no longer allowed.