Been looking for some definitive IP list sources maintained by the owner and not guessed at by 3rd parties by observation and a couple I came across are:
Microsoft's Azure Cloud Services provides an XML file:
Google provides a simple list in DNS from the command line:
nslookup -type=TXT _netblocks.google.com
_netblocks.google.com text = "v=spf1 ip4:220.127.116.11/19 ip4:18.104.22.168/19 ip4:22.214.171.124/20 ip4:126.96.36.199/18 ip4:188.8.131.52/17 ip4:184.108.40.206/20 ip4:220.127.116.11/16 ip4:18.104.22.168/20 ip4:22.214.171.124/20 ip4:126.96.36.199/16 ?all"
Anyone else got any direct IP list sources like these for Yahoo, Bing, etc.?