Robtex

Up: 221.149.160.0/23
Can't show all results, try to descend to a more specific CIDR
Down left: 221.149.161.0/25
Down right: 221.149.161.128/25
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
221.149.161.15	A+PTR	ns.krcert.or.kr
221.149.161.15	A	ns.krcert.org
221.149.161.15	A	ns2.knsp.org
221.149.161.16	A	ns2.krcert.or.kr
221.149.161.16	A	ns2.solution11.net
221.149.161.17	A	midas.krcert.net
221.149.161.19	A	imss.krcert.or.kr
221.149.161.20	A	cert.krcert.or.kr
221.149.161.21	PTR	www.krcert.or.kr
221.149.161.21	A	krcert.org
221.149.161.21	A	www.certcc.or.kr
221.149.161.60	A+PTR	ns.knsp.org
221.149.161.60	A	s4.knsp.org
221.149.161.161	A	mail.knsp.org
221.149.161.251	A	ns3.certcc.or.kr