Filtered Telnet

[LordWire]

What is meant but telnet being filtered, is it behind a packet-filtering firewall or what.
eg:

nmap IPgosehere -P0
starting nmap

21 ftp open
22 ssh open
23 telnet FILTERED --what is meant by this.
24 smtp open

[thread_killer]

Filtered ports are ports that don't reply to the portscan at all.

[LordWire]

I did a portscan on the host and it said telnet was filtered I got a result from the portscan.

[pooh sun tzu]

In short it means that the port (telnet) may be open but is only allowing access to certain computers. Example:

1. Your computer says "Hi" to the computer you scanned
2. The computer you scanned thinks "Is this one of the computers I'm allowed to talk to?"
3. If you are one of the computers it knows it is allowed to talk to then it replies "Hey there!"
4. If you are not one of the computers it knows it is allowed to talk to, then it remains silent or for sake of example says "I can't talk to you, I'm not allowed"

So in theory there is a service (telnet) running on that computer ,but your computer does not have permission to use it.

edit Stop negging the parent post just because it's a beginner question. We all started out somewhere, so don't forget it.