Re: closed ports filtered ???

[Maciej Soltysiak]

> 1. A SYN-ACK response: this means the port is open and accepting connections
> 
> 2. An ICMP 'port unreachable' mening the port is closed and not accepting 
> connections.
> 
> 3. Nothing at all, which tells nmap that something is blocking access, 
> because a normal TCP/IP stack would respond with one or other of the above.
> 
> (There are other possibilities such as ICMP redirect, TCP RST etc: I'm not 
> sure what nmap tells you when it gets one of these)
Closed. Normally on all sane tcp stacks RST is sent to say:
"go away, no services here"