>time to this mail. the question is how can i test or identify that i am 
>sitting behind a NAT box or not?. i request you kindly to spare some time to 

Well, surely the idea of a NAT is that you don't know it's there...?
Do you mean specifically how to tell on NetBSD/arm32? I don't think it's 
architecture specific....
Have you looked at traceroute(1)?

from FOLDOC:

Network Address Translation

<networking> (NAT, or Network Address Translator, Virtual LAN) A hardware device 
currently being developed and used to extend the Internet
addresses already in use. NAT has been suggested as an alternative to adopting 
IPv6 (IPng). It allows duplicate IP addresses to be used within a
corporation and unique addresses outside. 

Sounds a bit kludgy to me.

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