Hi, On Wed, Jul 08, 2026 at 01:47:36PM -0400, Stefan Monnier wrote: > FWIW, I tried `nc` for that (because I like `nc` for actual transfers) > but didn't like it because it doesn't give enough feedback. I just > tried `socat` and it similarly just "sits there" sometimes, at which > point I have to use my head to try and guess if it means it successfully > connected but the other end doesn't send anything, or if it means it's > still waiting for the connection to be established, etc...
I've never really had a problem with "nc -zv example.com 25" or whatever. Except for remembering to use it. 😀 Some text-based protocols don't send any banner unless you send them something first, so then I'd have to omit the -z. > I think what I'd want is a UI a bit more like `ping`: I give it > a hostname and a port, and it tells me when it starts to try and > establish the connection (showing the IP address used), and then telling > me whether the connection was successful or not (even better if it can > show me the first few bytes received from the server, if any, but it > should disconnect automatically) or whether it timedout. > > Any recommendation? You can put a timeout on nc, like: $ nc -w 1 -v mail.bitfolk.com 25 Connection to mail.bitfolk.com (85.119.80.223) 25 port [tcp/smtp] succeeded! 220 mail.bitfolk.com ESMTP Exim v4.something Wed, 08 Jul 2026 17:56:31 +0000 (it closed the connection by itself) but again, sometimes services won't say anything unless you talk first, so you'd get 1 second of nothing. A traceroute using TCP is also sometimes useful to find *where* the packets die, in case of possible firewalling. Thanks, Andy -- https://bitfolk.com/ -- No-nonsense VPS hosting <Ging> i stopped taking my medication long ago. the ironey is it was for social anxioty disorder and now i daren't go back to the doctor to get another perscription
