PermissionError on Port 502

[bitwicht]

• ModBus TCP proxy version: [v0.6.7]
• Python version:
• Operating System:

I need to start the server on port 502, because i have an device where i cant change the port.

xx@raspberrypi:~/.local/bin $ ./modbus-proxy -b tcp://0:502 --modbus tcp://192.168.0.123:1502 2024-01-01 15:48:23,252 INFO modbus-proxy: Starting... Traceback (most recent call last): File "/home/pi/.local/bin/./modbus-proxy", line 8, in sys.exit(main()) File "/home/pi/.local/lib/python3.9/site-packages/modbus_proxy.py", line 343, in main asyncio.run(run()) File "/usr/lib/python3.9/asyncio/runners.py", line 44, in run return loop.run_until_complete(main) File "/usr/lib/python3.9/asyncio/base_events.py", line 642, in run_until_complete return future.result() File "/home/pi/.local/lib/python3.9/site-packages/modbus_proxy.py", line 338, in run await run_bridges(bridges, ready=ready) File "/home/pi/.local/lib/python3.9/site-packages/modbus_proxy.py", line 327, in run_bridges await start_bridges(bridges) File "/home/pi/.local/lib/python3.9/site-packages/modbus_proxy.py", line 320, in start_bridges await asyncio.gather(*coros) File "/home/pi/.local/lib/python3.9/site-packages/modbus_proxy.py", line 188, in start self.server = await asyncio.start_server( File "/usr/lib/python3.9/asyncio/streams.py", line 94, in start_server return await loop.create_server(factory, host, port, **kwds) File "/usr/lib/python3.9/asyncio/base_events.py", line 1494, in create_server raise OSError(err.errno, 'error while attempting ' PermissionError: [Errno 13] error while attempting to bind on address ('0.0.0.0', 502): permission denied

Other Question: Modbus Slave is: 192.168.0.123:1502 Modbus Master is: 192.168.0.11 and an other one ist Modbus Master is: 192.168.0.12

I want collect the Modbus Date vom 192.168.0.123:1502 and give it to both masters.

Can i also collect from 192.168.0.123:1502 and open two ports on the proxy

modbus-proxy -b tcp://0:502 AND tcp://0:503 --modbus tcp://192.168.0.123:1502 ????

If the Master x.x.x.12 is collect from x.x.x.1502 the other master can not collect from x.x.x.1502

[Richigeht]

Hi

port 502 is system exclusive - run as sudo if you require system ports.

[tiagocoutinho]

Agree with @Richigeht .

Prefix your command wit sudo if you need to serve modbus-proxy on privileged port(s).