TCP IN node not receiving data

General
1

Hello,
I am trying to receive XML response data back from a Printer over TCP connection.

I am able to connect to the printer and successfully send XML commands using the TCP Out node at 192.168.1.105 port 9900. I can see the XML data being sent and the XML response from the Printer using Wireshark, but the TCP IN node never shows anything incoming.

I should have the TCP In node set to Listen On port 9900 correct?

I setup a test TCP response flow in Node-Red on a separate computer and the Raspberry Pi received the response.

I tried setting up tcpdump to relay all traffic coming from 192.168.1.105 to localhost port 9901 and setup a TCP In node listening to port 9901. This doesn't seem to work very well because there is a long delay (30 seconds or more) and it doesn't seem to capture all incoming data.

Any suggestions or ideas are greatly appreciated!!

Running Node-Red version 3.1.9 on Raspberry Pi 4
Operating System: Debian GNU/Linux 12 (bookworm)
Kernel: Linux 6.6.20+rpt-rpi-v8

Node-Red flow

node-red TCP flow
node-red TCP flow1200×838 167 KB

Wireshark screenshots:

wireshark screenshot 1
wireshark screenshot 11211×101 42.8 KB

wireshark screenshot 2
wireshark screenshot 21300×276 106 KB

wireshark screenshot 3
wireshark screenshot 31301×251 101 KB

2

Did you try the tcp-request node, rather than the out and in nodes, as it is meant for more this command/ response type of interaction

3

I did try using the TCP Request node, but I didn’t see any response using debug nodes with that either. Maybe I didn’t have it setup correctly.
I’ll do some more research and testing with the request node.

Any advice on the request node?

Thanks for the response!