Cannot properly test TCP connectivity

Hi guys,

I was testing a new home network setup and using common testing tools I have being used in Linux/Windows and previous MacOS versions, like telnet, tcping and even wget.

Strangelly I noticed that all these tools are listing results as TCP connection ok and port open even on non existing hosts ... no resolved entry on arp tables, etc.

$ tcping 192.168.0.22 80

192.168.0.22 port 80 open.

$ wget http://192.168.0.22

--2018-12-28 10:31:39--  http://192.168.0.22/

Connecting to 192.168.0.22:80... connected.

HTTP request sent, awaiting response... ^Z

[1]+  Stopped                 wget http://192.168.0.22

$ netstat -n | grep 192.168.0.22

tcp4       0      0  192.168.0.13.50888     192.168.0.22.80        SYN_SENT   

$ arp -a | grep 192.168.0.22

? (192.168.0.22) at (incomplete) on en1 ifscope [ethernet]

Sometimes Telnet stays connected for quite some time and sometimes it closes connection immediately and not issuing echos of what I type, like if I was localhost connected:

$ telnet 192.168.0.22 80

Trying 192.168.0.22...

Connected to 192.168.0.22.

Escape character is '^]'.

abcdeafght

^]

telnet> quit

Connection closed.

$ telnet 192.168.0.22 80

Trying 192.168.0.22...

Connected to 192.168.0.22.

Escape character is '^]'.

Connection closed by foreign host.

Any1 know if it's a High Sierra issue ?