If that's a specific tool name, I haven't used it. I'm assuming, however, that it does reverse lookups against DNS name servers, to get all hosts resolving to the given IP, or IP's in the address range of the host.
i have been talking about this tool "hayabusa"
http://www.yougetsignal.com/tools/web-sites-on-web-server/
I often run python and bash scripts to do the same, querying name servers for a given domain, then reverse-resolving the IP's for their assigned blocks, against the name servers. (So yes to #1, you could do it, for yourself, without a pre-canned tool / manually)
i would like to see such scripts/code,do you have any publicly available scripts,got any ?
#2 - sure you can trust it. Worst case, they're webservers. Once you get their hostnames, visit them, to confirm.
#3 - again, reverse name resolution from the name servers
we have been speaking about reverse dns look-up and all for findind them,but they had mentioned like this
Data is gathered from search engine results, which are not guaranteed to be complete.
That is why i had asked about the accuracy of the results

I think they are doing a simple thing in a very complex manner,may be there should be some reasons...
It's one of the MANY things you MIGHT do, during OSCP study (as well as in live pentesting...)
Thanks for the hint

There will of course, in most cases even be a reverse DNS record (PTR, which means Pointer most likely), which uses the IP-address and points to a hostname.
Read up on what x.x.x.x.in-addr.arpa addresses are Wink (Pretty much not the direct answer you were looking for, but valuable information.)
yes maxe ,it is not the direct answer i am looking for,
may be i should digg this a lot deeper...

between if you got any simple public scripts for this ,pass here
