Description of problem: nc no longer supports -z switch as before. -z Specifies that nc should just scan for listening daemons, without sending any data to them. It is an error to use this option in conjunction with the -l option. This introduces random incompatibility (for example Bug 891109) as nc is used like in scripts to verify that port is open. Nc is used as it is a tool that is usually present on the system and can be used by unprivileged user. Version-Release number of selected component (if applicable): nmap-ncat-2:6.47-2.fc22.x86_64 : Nmap's Netcat replacement How reproducible: always Steps to Reproduce: 1. run nc -zv <machine> <port> Actual results: $ nc -zv localhost 2222 nc: invalid option -- 'z' Ncat: Try `--help' or man(1) ncat for more information, usage options and help. QUITTING. Expected results: $ nc -zv localhost 22 Connection to localhost 22 port [tcp/ssh] succeeded! or $ nc -zv localhost 666 nc: connect to localhost port 666 (tcp) failed: Connection refused Additional info: Maybe, if the replacement for nc is is incomplete, until it is finished the original package should be put back at least as an optional package that can be installed and configured using update-alternatives.
(In reply to Jakub Vavra from comment #0) > Description of problem: > nc no longer supports -z switch as before. > > -z Specifies that nc should just scan for listening daemons, without > sending any data to them. It is an error to use this option in > conjunction with the -l option. This was discussed some time ago. This change won't be accepted upstream. If you want to test open ports, you should use nmap > Additional info: > Maybe, if the replacement for nc is is incomplete, until it is finished ncat is "finished", it is not a drop-in replacement and never will be > the original package should be put back at least as an optional package that can > be installed and configured using update-alternatives. It does not depend on me. You'd have to find someone willing to maintain nc. Then I can remove the nc->ncat link so it won't conflict with it. I won't argue :)