while true do time echo test | ssh user@machine.somewhere <mailto:user@machine.somewhere> cat done But for a remote rpc service that requires low latency, take a look at multiplexing https://en.wikibooks.org/wiki/OpenSSH/Cookbook/Multiplexing and daemonize the Master connection > On 28. 7. 2023, at 0:33, Roland Mainz <roland.mainz@xxxxxxxxxxx> wrote: > > On Thu, Jul 27, 2023 at 11:28 PM Michael Loftis <mloftis@xxxxxxxxx> wrote: >> On Thu, Jul 27, 2023 at 3:23 PM Roland Mainz <roland.mainz@xxxxxxxxxxx> wrote: >>> Before I start writing one myself... >>> ... did anyone ever wrote a tool to measure the latency of a ssh >>> connection, a la "ping" ? >> >> That gets...really complicated... Because what exactly do you want to >> measure? > > We want to profile some kind of ancient self-made RPC system, and > therefore we need to measure the time starting from writing a string > into ssh stdin, get on the remote side /bin/cat to send it back, and > then stop the clock when the string comes out of ssh's stdout. And > that in a form of endless loop, for around one hour (just to be sure > that the overhead of the ssh protocol negotiation details and network > noise don't ruin the measurements...). > > Or short: Round-trip latency of data passed to a remote /bin/cat. And > that for every possible ssh -c cipher > > ---- > > Bye, > Roland > -- > __ . . __ > (o.\ \/ /.o) roland.mainz@xxxxxxxxxxx > \__\/\/__/ MPEG specialist, C&&JAVA&&Sun&&Unix programmer > /O /==\ O\ TEL +49 641 3992797 > (;O/ \/ \O;) > _______________________________________________ > openssh-unix-dev mailing list > openssh-unix-dev@xxxxxxxxxxx > https://www.google.com/url?q=https://lists.mindrot.org/mailman/listinfo/openssh-unix-dev&source=gmail-imap&ust=1691102292000000&usg=AOvVaw3gpKfyFOLZGNpRePx3xCKW _______________________________________________ openssh-unix-dev mailing list openssh-unix-dev@xxxxxxxxxxx https://lists.mindrot.org/mailman/listinfo/openssh-unix-dev
