Address already in use when setting up device server

[GZLiew]

HI @ChristianTremblay
im trying to setup a device servers to test my bacnet client

I folowed your guide on setting up the ip addresses here #254

but I am getting a Address already in use error

heres my config

> ifconfig | grep "inet " | grep -v 127.0.0.1
        inet 192.168.1.32 netmask 0xffffff00 broadcast 192.168.1.255
        inet 192.168.211.55 netmask 0xffffff00 broadcast 192.168.211.255
        inet 192.168.211.54 netmask 0xffffff00 broadcast 192.168.211.255

>>> import BAC0
>>> bacnet = BAC0.lite(ip='192.168.211.54/24')           2023-09-27 14:17:41,067 - INFO    | Starting BAC0 version 23.07.03 (Lite)
2023-09-27 14:17:41,068 - INFO    | Use BAC0.log_level to adjust verbosity of the app.
2023-09-27 14:17:41,068 - INFO    | Ex. BAC0.log_level('silence') or BAC0.log_level('error')
2023-09-27 14:17:41,069 - INFO    | Starting TaskManager
2023-09-27 14:17:41,070 - INFO    | Using ip : 192.168.211.54 on port 47808 | broadcast : 192.168.211.255
2023-09-27 14:17:41,095 - INFO    | Starting app...
2023-09-27 14:17:41,095 - INFO    | BAC0 started
2023-09-27 14:17:41,095 - INFO    | Registered as Simple BACnet/IP App
2023-09-27 14:17:41,095 - INFO    | Device instance (id) : 3056898
2023-09-27 14:17:41,098 - INFO    | Update Local COV Task started (required to support COV)
>>> bacnet = BAC0.lite(ip='192.168.211.55/24')
2023-09-27 14:18:01,272 - INFO    | Starting BAC0 version 23.07.03 (Lite)
2023-09-27 14:18:01,272 - INFO    | Use BAC0.log_level to adjust verbosity of the app.
2023-09-27 14:18:01,272 - INFO    | Ex. BAC0.log_level('silence') or BAC0.log_level('error')
2023-09-27 14:18:01,273 - INFO    | Using ip : 192.168.211.55 on port 47808 | broadcast : 192.168.211.255
2023-09-27 14:18:01,274 - ERROR   | an error has occurred: [Errno 48] Address already in use

[bbartling]

some other program is using port 47808 most likely? What happens if you reboot or try finding what PID is using port 47808 UDP

[GZLiew]

which command do you use to search UDP ports?

[bbartling]

At least according to Chat GPT: To search for a program or PID using UDP ports on Linux, you can use the netstat or ss command in combination with other tools like grep or awk. In your specific case, you want to search for UDP port 47808, which is commonly used for BACnet. Here's how you can do it using netstat and grep:

netstat -tuln | grep 47808

Here's what this command does:

netstat: This command is used to display network-related information, including active network connections and listening ports.
-tuln: These options are used to filter the output to only show UDP (-u) listening (-l) ports and display numeric addresses instead of resolving hostnames (-n).

grep 47808: This part of the command searches for the line that contains the UDP port 47808.
The output will show you the program (if any) listening on UDP port 47808 and its associated PID.

Alternatively, you can use the ss command with similar options:

ss -tuln | grep 47808

Both commands should provide you with information about any program or process listening on UDP port 47808 for BACnet.

[bbartling]

I am sort of a newb in this stuff but i have a Docker container running a BACnet script (so I know that already) but I like this one: (curious if anyone else knows of easier ways)

bbartling@benspi:~ $ ss -tuln | grep 47808
udp   UNCONN 0      0            0.0.0.0:47808      0.0.0.0:*
udp   UNCONN 0      0                  *:47808            *:*
bbartling@benspi:~ $ sudo fuser -v -n udp 47808
                     USER        PID ACCESS COMMAND
47808/udp:           root       7526 F.... docker-proxy
                     root       7533 F.... docker-proxy

i think once you find the PID number just kill it:
For example, if the PID is 12345:

sudo kill 12345