Comments on: How to Check Remote Ports are Reachable Using ‘nc’ Command

By: Chris

Chris — Tue, 13 Apr 2021 16:13:09 +0000

This tool sucks, nc -zv says every port succeeds even ones I just make up. Why can't it 'just work' and give real meaningful information as telnet did which wasn't even designed to test if a port was open.

By: Miki

Miki — Mon, 13 Jan 2020 23:01:29 +0000

I hope you are still taking comments…it’s been a while.

This was almost the best set of instructions I’d run into except it doesn’t cover how to interpret the results. If you provided a sample of success or failure as an example I’d never have to look anywhere else.

For now, if the results in Redhat 7 are similar to below is the port open or filtered/closed

Ncat: Version 7.50 ( https://nmap.org/ncat )
Ncat: Connected to 192.168.1.15:8001.
Ncat: 0 bytes sent, 0 bytes received in 5.03 seconds.

I’m confused by the fact that I’m connected which I think means the port is open but no data was sent or received.

Thanks

By: Mark T Lakata

Mark T Lakata — Fri, 09 Aug 2019 23:11:14 +0000

In reply to Erick Gonzalez. The '-z' flag is available in ncat 7.5, but not in ncat 6.4

By: Aaron Kili

Aaron Kili — Wed, 07 Mar 2018 07:27:37 +0000

In reply to Erick Gonzalez.

@Erick

Many thanks for the useful info, we will check this out.

By: Erick Gonzalez

Erick Gonzalez — Tue, 06 Mar 2018 17:17:45 +0000

In reply to Aaron Kili. The -z option has been removed as of Ncat version 6.40. The new option is --recv-only.