Am 11.04.2024 um 15:49 schrieb Marc SCHAEFER: > Hello, > > On Tue, Apr 09, 2024 at 03:13:01PM +0200, DdB wrote: >> from my research, the abbreviated takeaway is: > > I never used mbuffer, I use buffer combined with netcat-traditional: > > # receiver (TCP server on port 8000) > nc -l -p 8000 | buffer -S 1048576 -s 32768 -o /dev/null > > # sender (TCP client on ephemeral port) > nc localhost 8000 < /dev/zero > > I just installed mbuffer: > > mbuffer -I 8000 -o /dev/null > > mbuffer -i /dev/zero -O 127.0.0.1:8000 > > and it also works. > >>> sudo netstat | grep $port >> to return nothing > > yes, but those work: > > netstat -a | grep :8000 > > netstat --listen | grep :8000 > > Maybe it's just that by default netstat only shows sockets in the > ESTABLISHED state and not in the LISTEN state. > >> What am i doing wrong? > > If there is a timeout, I would suggest to investigate firewalls > on the server side. > >
Thank you for your (and everyone else)'s hints. It is working now. The lessons learned: - in fact netstat is somewhat outdated, ss is the replacement (package iproute2 instead of net-tools) - yes, and my attempt at checking just failed, as you kindly pointed out, due to missing out on listening ports. LOL - when using mbuffer from a pipe, it is important to say "-i - " in the arguments (missed that at first) - the resulting transfer is way faster than say ... ssh.
