Expected behaviour
Only the host which are reachable should be up …
Last login: Mon May 30 10:03:50 on ttys001
Philippes-MacBook-Pro:~ xxradar$ nmap -sP 192.168.123.0/24
Starting Nmap 7.11 ( https://nmap.org ) at 2016-05-30 10:05 CEST
Nmap scan report for 192.168.123.2
Host is up (0.0074s latency).
Nmap scan report for 192.168.123.3
Host is up (0.0037s latency).
Nmap scan report for 192.168.123.12
Host is up (0.0094s latency).
Nmap scan report for 192.168.123.13
Host is up (0.0053s latency).
Nmap scan report for 192.168.123.20
Host is up (0.031s latency).
Nmap scan report for 192.168.123.21
Host is up (0.00018s latency).
Nmap scan report for 192.168.123.25
Host is up (0.0064s latency).
Nmap scan report for 192.168.123.35
Host is up (0.0037s latency).
Nmap scan report for 192.168.123.44
Host is up (0.067s latency).
Nmap scan report for 192.168.123.48
Host is up (0.0066s latency).
Nmap scan report for 192.168.123.80
Host is up (0.0063s latency).
Nmap scan report for 192.168.123.81
Host is up (0.031s latency).
Nmap scan report for 192.168.123.250
Host is up (0.0096s latency).
Nmap scan report for 192.168.123.253
Host is up (0.039s latency).
Nmap scan report for 192.168.123.254
docker run -it xxradar/hackon nmap -sP 192.168.123.0/24
Actual behaviour
docker run -it xxradar/hackon nmap -sP 192.168.123.0/24
Starting Nmap 6.40 ( http://nmap.org ) at 2016-05-30 08:03 UTC
Nmap scan report for 192.168.123.0
Host is up (0.00028s latency).
Nmap scan report for 192.168.123.1
Host is up (0.00035s latency).
Nmap scan report for 192.168.123.2
Host is up (0.00026s latency).
Nmap scan report for 192.168.123.3
Host is up (0.00025s latency).
Nmap scan report for 192.168.123.4
Host is up (0.00024s latency).
Nmap scan report for 192.168.123.5
Host is up (0.00022s latency).
Nmap scan report for 192.168.123.6
Host is up (0.00021s latency).
Nmap scan report for 192.168.123.7
Host is up (0.00020s latency).
Nmap scan report for 192.168.123.8
Host is up (0.00019s latency).
Nmap scan report for 192.168.123.9
Host is up (0.00020s latency).
Nmap scan report for 192.168.123.10
Host is up (0.00020s latency).
Nmap scan report for 192.168.123.11
Host is up (0.00027s latency).
Nmap scan report for 192.168.123.12
Host is up (0.00025s latency).
Nmap scan report for 192.168.123.13
Host is up (0.00037s latency).
Nmap scan report for 192.168.123.14
Host is up (0.00033s latency).
Nmap scan report for 192.168.123.15
Host is up (0.00051s latency).
Nmap scan report for 192.168.123.16
Host is up (0.00052s latency).
Information
Seems that a ping or scan using ICMP marks all non-existing hosts as UP
Steps to reproduce the behavior
see commands above.