What is in-addr.arpa?

[DC]

I'm using Zone Alarm and wonder whether I need to allow this
incomming? It comes from different IP's (appears to change daily).
The incoming destination changes, but usually is 68.76.166.xxx. I did
a search for the name and came up with references in an advanced
network group (I forget the group). I never could figure out what it
was for, but suspect it might be a server configuration tool.

Dave

 

[Guest]

in-addr.arpa is part of the dns reverse lookup. I.E:-
instead of the DNS server taking a computer/website name
and looking up the IP address for it (forward lookup), it
takes the IP address and looks up the name (reverse
lookup)

 

[DC]

Thanks. Is there any reason I shoud allow this through to my computer?

 

[Guest]

I can't think why it would be necessary on a home
computer, unless your isp requires it. (though someone
else may have more information). You could disallow it
for now on an ad hoc basis and see if it has any affect
on your browsing, if not, then tick the box to block it
always. If it affects your ability to browse, then you
can set zone alarm to allow it. My knowledge of DNS is
fairly basic so it may be a little bit of trial and error
required- I wouldn't like to give a definitive answer.