It doesn't have to be an php function.
There are search machine ip collectors fetching ipadresses like: http://bgp.he.net/net/220.127.116.11/21#_dns
But they have outdated data. The website www.dev4me.nl
(Ruud's) run on 18.104.22.168 and it is not listed there. Even the company's site isn't listed.
I am having some trouble convincing the webhostcompany, owner of that range, that most of his hosted sites can't be reached by work internetconnections (8 connections serving 2800 pc's!). Might have to do with young inexperienced cheap support people.
Stupid answers like if you can ping we don't block while telnet 80 doesn't connect etc. Allso it looks like answers have a obligate 24 hour delay.
The blocking seems rangewise.
When I can show them how much websites we can't reach maybe they will listen.
The only one I currently know wich work a bit is bgp.he.net, but I don't trust it since dev4me isn't in the list.
I know the nameservers of that company, they lie in the same range and have ofcouse dnsports opened.
So I could go 2 ways, preferably both:
1 - reverse ip lookup harvesters, like bgp.he.net
2 - read dns servers 'A' records wich give allso load of ipadresses wich aren't there, but I hope allso a load who are (they sell resellers plans real cheap)
But don't have the (online-)tools to start, thus my question.
Thanx in advance,