telnet
netcat
web
HTTP HEAD REQUEST
telnet balaskas.gr 80 Trying 158.255.214.14... Connected to balaskas.gr (158.255.214.14). Escape character is '^]'. HEAD / HTTP/1.1 HOST: balaskas.gr HTTP/1.1 200 OK Date: Wed, 15 Jul 2015 13:11:42 GMT Server: Apache Vary: Accept-Encoding,User-Agent Content-Type: text/html; charset=UTF-8 Content-Language: el
$ nc -v ebalaskas.gr 80
GET / HTTP/1.1
HOST: ebalaskas.gr
[double enter]
port knocking/scanning
telnet
web
IMAP4 (TCP PORT 143)
POP3