Re: Weird results from nmap

[Martin Husemann <martin%duskware.de@localhost>]

On Fri, Nov 11, 2016 at 08:31:00PM +0000, coypu%SDF.ORG@localhost wrote:
> Hi,
> 
> I noticed that if I use nmap, it will always say that a port is open.
> (nmap -O will even say it cannot find a single closed port)
> Which is obviously not true for some of the servers I've checked.. I think.

What exactly are you testing? It seems to work fine for me; typical output
from nmap -v $one_of_my_servers:

PORT     STATE SERVICE
22/tcp   open  ssh
53/tcp   open  domain
80/tcp   open  http
111/tcp  open  rpcbind
139/tcp  open  netbios-ssn
445/tcp  open  microsoft-ds
1022/tcp open  exp2
1023/tcp open  netvenuechat
2049/tcp open  nfs


and against localhost:

Starting Nmap 7.30 ( https://nmap.org ) at 2016-11-12 11:01 CET
Initiating Ping Scan at 11:01
Scanning localhost (127.0.0.1) [2 ports]
Completed Ping Scan at 11:01, 0.00s elapsed (1 total hosts)
Initiating Connect Scan at 11:01
Scanning localhost (127.0.0.1) [1000 ports]
Increasing send delay for 127.0.0.1 from 0 to 5 due to 43 out of 141 dropped probes since last increase.
Discovered open port 6000/tcp on 127.0.0.1
Completed Connect Scan at 11:01, 18.17s elapsed (1000 total ports)
Nmap scan report for localhost (127.0.0.1)
Host is up (0.000053s latency).
Other addresses for localhost (not scanned): ::1
Not shown: 999 closed ports
PORT     STATE SERVICE
6000/tcp open  X11

Read data files from: /usr/pkg/bin/../share/nmap
Nmap done: 1 IP address (1 host up) scanned in 18.28 seconds

(and yes, I explicitly manually configured X on this machine to listen via
tcp).

Martin