Robtex

Up: 211.172.240.0/22
Can't show all results, try to descend to a more specific CIDR
Down left: 211.172.242.0/24
Down right: 211.172.243.0/24
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
211.172.242.6	PTR	mail0.tourexpress.com
211.172.242.24	PTR	anti0.tourexpress.com
211.172.242.26	PTR	mail.btnikorea.com
211.172.242.53	A	chatudy.com
211.172.242.66	A	ns1.krsys.net
211.172.242.76	A	ecard.nate.com
211.172.242.81	A	krsys.net
211.172.242.81	A	www.krsys.net
211.172.242.101	A	gotobuddha.org
211.172.242.101	A	www.nungin.net
211.172.242.101	A	mail.nungin.net
211.172.242.131	PTR	mail.banaple.co.kr
211.172.242.131	PTR	mail.banaplefnb.com
211.172.242.131	PTR	mail.logisoft.co.kr
211.172.243.74	A	carrotenglish.net
211.172.243.76	A	www.bhappy.co.kr
211.172.243.76	A	thetranscat.com
211.172.243.76	A	www.speakingmaniac.co.kr
211.172.243.83	A	seoulevms.net
211.172.243.92	PTR	mail.blueinter.com
211.172.243.92	PTR	mail.blueinter.co.kr
211.172.243.242	A	hellodc.co.kr
211.172.243.251	A	mail.daumlmc.com