TELNET instead PING

[Gandalf]

>
>> Note: that reason you talked about is most likely a packet filtering 
>> firewall. A good firewall
>> can block PING, Telnet, Nbsession and many others. In most cases, the 
>> best policy
>> is to lock everything by default and permit only the ones you really 
>> want. Firewall
>> rules can include source addresses too. It is possible that a 
>> computer do not respond
>> on PING and TELNET ports for you but it does for a similar request 
>> from another
>> computer. I think there is no universal way to determine if a remote 
>> host is alive or not.
>
>
> If we are talking about IP network segment in the same ethernet layer, 
> can you ignore my ARP request - who-has <your-ip> ?
>
Probably I cannot. :-)
But this applies only when you are in the same segment.
By the way, is it possible to send an ARP request from pure Python? ;-)
AFAIK Python provides tools for level 3 and above only.