Sending packets to Lantronix module via Packet Sender (version 6.2.3) - Could not connect

[DavidVaknine]

OS: Windows10
Hi All,

I am using Lantronix module (XP1001000-05R) on a controller.
Here is a link forLantronix module: https://www.lantronix.com/wp-content/uploads/pdf/XPort_PB.pdf
When sending a packet on the IP address/port of this module, I get "Could not connect" error.

But when using Tibbo module, it works properly.
Her is a link for Tibbo module: http://tibbo.com/store/addons/rj203.html

I have no antivirus/firewalls.
Any idea please?

[dannagle]

Are you certain you have the target IP correct? Try some ping tests (though ping is not always enabled --it usually is). Also, the documentation says it could listen on 10001 or 10002. Have you tried 10002?

Also, some devices support a web interface, so you could try connecting with your browser. Sometimes control servers have to be enabled first through a web interface.

[DavidVaknine]

Hi Dan,

Thanks for your reply.
Yes, IP correct. Ping OK, see the following screenshot.

Our installations over the world are all with port 10001 regarding Lantronix modules, so our tests must be realized on this specific port.
No difference using port 10001 or 10002: still "Could not connect" error.
Take a look at this video link with all web configuration details: https://gofile.io/?c=ajgFaf
Should I change some parameters please?

Thanks and Best Regards,
David

[dannagle]

I watched the video. Nothing in particular jumped out at me except perhaps missing a Gateway. Without a GW, you won't be able to control the device outside your local subnet. I'm not convinced that is the problem, but it is worth looking at.

I also saw telnet disabled. Telnet is basically plain TCP with some control codes. I equate the two, but Lantronix may consider them separate. Perhaps telnet could be a fallback option.

Is something else already connected to your Lantronix? Some weaker devices can only sustain a single TCP connection at a time. If you can, try making an isolated network with just you and the Lantronix.

Packet Sender runs as a user app and thus does not always know the inner details of why something did not connect. You could have Wireshark listen in the background. Wireshark may give you more info of why a connection was not made.

Also, if you know the web port is working, as a quick sanity check you can have Packet Sender send to port 80. That will check that there isn't some deeper problem with establishing a TCP session to that address.

[DavidVaknine]

Hi Dan,

Nothing in particular jumped out at me except perhaps missing a Gateway.

The device should be controlled only inside a local subnet so the GW is not the matter.

I also saw telnet disabled. Telnet is basically plain TCP with some control codes. I equate the two, but Lantronix may consider them separate. Perhaps telnet could be a fallback option.
Please see the result when Telnet is enabled. Note that most customers' installations do not use this configuration.

Let me explain the goal of our tests:
Our controllers (communicating with IP addresses via Lantronix/Tibbo modules) are used for access control allowing to open doors, generate alarms, etc.
In some rare cases, network traffic is heavily broadcasted and our controllers stop polling.
We want to reproduce such conditions by broadcasting on the full network and send packets.
We need to send packets on a 'live' system with events (doors opened, alarms, videos,..) so Lantronix modules must always be connected.
It is true that if the controllers stop polling so I can send packets properly as described on the following capture.

But for our tests, controllers must be in polling mode...
How to do make this please?

[dannagle]

That first screenshot looks like telnet control codes, so that is a successful test. I know telnet is not what you are looking for, but it is nice to see something is working.

If you are trying to flood your network, there is a special tool in the latest Packet Sender. Go to "Tools --> Intense Traffic Generator". This an experimental tool that allow you to send a large number of UDP packets to a particular address. Set the delay to zero for as fast as possible.

If you want to recreate flooding on a connected device, you can turn on "Persistent TCP" checkbox, make your TCP connection, and then launch that separate UDP flooding tool.