From my windows 10 machine (172.18.164.50) if I do a
telnet 172.20.187.10 443
It shows a blank screen as if it is connected.
It is totally unespected because in theory a firewall is blocking the traffic to port
Looking in Message Analyser (filtering network card with source or destination
172.20.187.10) I see SYN message and Retransmit SYN, with no ACK-SYN reponse.
If I try a
telnet 172.20.187.10 666 it shows typical message "Could not open connection to..." In this case it is expected because there is nothing on the server listening on port
Again looking in Message Analyser I see the very same SYN messages (with different port number) with no ACK-SYN.
Why is telnet acting so differently if TCP messages look the same?