UDP weird issue : accessible on localhost but not on laptop IP (TCP working fine)

General Discussions
1

Hi,
I am using a Debian bookworm (testing) with docker version 20.10.14+dfsg1, build a224086

First run a fake listener inside docker using netcat

docker run -p 51000:51000/udp -it subfuzion/netcat -ul 51000

Then I try to use netcat to see if I can see the udp port open on both localhost and the IP of my machine (192.168.1.18)

> nc -v -u -z -w 3 localhost 51000
Ncat: Version 7.92 ( https://nmap.org/ncat )
Ncat: Connected to ::1:51000.
Ncat: UDP packet sent successfully
Ncat: 1 bytes sent, 0 bytes received in 2.00 seconds.
> nc -v -u -z -w 3 192.168.1.18 51000
Ncat: Version 7.92 ( https://nmap.org/ncat )
Ncat: Connected to 192.168.1.18:51000.
Ncat: Connection refused.

FYI if I use tcp everything works, netcat can connect on locahost and on my machine IP too

Any idea if it is a bug ? what I can provide to help investigations ?

Regards,

2

Finally found the issue : I was using the default version of docker used by my distribution instead of following

Once using ocrrect versions it worked fine.
So this post can be burried somehwere