Robtex

Up: 159.255.136.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 159.255.136.0/23
Down right: 159.255.138.0/23
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
159.255.137.6	A+PTR	ip-159-255-137-6.in-addr.ntrnet.it
159.255.137.164	PTR	ip-159-255-137-164.in-addr.ntrnet.it
159.255.137.164	A	mx2.dmpack.it
159.255.137.200	A	posta.fondsilvestri.com
159.255.138.27	PTR	ip-159-255-138-27.in-addr.ntrnet.it
159.255.138.27	A	webmail.schib.it
159.255.138.27	A	mail.schib.it
159.255.138.82	A+PTR	ip-159-255-138-82.in-addr.ntrnet.it
159.255.138.82	A	mail2.sisma.com
159.255.138.122	PTR	ip-159-255-138-122.in-addr.viatek.it
159.255.138.122	A	ip-159-255-138-122.in-addr.ntrnet.it
159.255.138.122	A	mail.renzi.it
159.255.138.138	A+PTR	ip-159-255-138-138.in-addr.ntrnet.it
159.255.138.138	A	mx1.feba.it
159.255.138.138	A	www.feba.it
159.255.138.205	A+PTR	mail.centropaghe.it
159.255.138.205	A	centropaghe.it
159.255.138.205	A	www.centropaghe.it
159.255.138.234	A+PTR	ip-159-255-138-234.in-addr.ntrnet.it
159.255.138.234	A	remote.compagniasiderurgica.com
159.255.138.234	A	compagniasiderurgica.com
159.255.139.43	A+PTR	mail.atispa.it
159.255.139.43	A	mail.valplastick.com
159.255.139.43	A	mail.vesticolor.it