Robtex

Up: 101.255.0.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 101.255.0.0/23
Down right: 101.255.2.0/23
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
101.255.0.1	PTR	mnt-gtw.tachyon.net.id
101.255.0.2	A+PTR	ns2.bhomert.com
101.255.0.4	A+PTR	lg.tachyon.net.id
101.255.0.5	A+PTR	hosting.tachyon.net.id
101.255.0.5	PTR	ns3.tachyon.net.id
101.255.0.5	A	yamahacikarang.com
101.255.0.6	PTR	ns4.tachyon.net.id
101.255.0.6	A	hosting.tachyon.net.id
101.255.0.10	A+PTR	smtp-client-1a0.tachyon.net.id
101.255.0.102	A	seal-revolution.com
101.255.0.103	PTR	ns1.anggireza.com
101.255.0.103	A	mail.anggireza.com
101.255.0.103	A	dc-0179ffdf.anggireza.com
101.255.0.104	PTR	mail2.tachyon.net.id
101.255.0.117	A+PTR	netmon.tachyon.net.id
101.255.0.117	A+PTR	speedtest.tachyon.net.id
101.255.0.118	PTR	mail2.tachyon.net.id
101.255.0.123	A	lokalhos.com
101.255.0.124	A	mail.lokalhos.com
101.255.2.10	A+PTR	mail.tachyon.co.id
101.255.2.10	A	mail2.tachyon.net.id