Robtex

Up: 58.185.80.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 58.185.80.0/23
Down right: 58.185.82.0/23
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
58.185.80.19	A	defu.idlabels-sg.com
58.185.80.19	A	mail.idlabels-sg.com
58.185.80.105	A	mail.myride.biz
58.185.80.121	PTR	mail.komayaships.com.sg
58.185.80.122	PTR	mail.komayaships.com.sg
58.185.80.125	PTR	mail.komayaships.com.sg
58.185.80.126	PTR	mail.komayaships.com.sg
58.185.80.164	A	mail.haolaihuat.com.sg
58.185.80.164	A	dongjian.com.sg
58.185.80.166	A	www.haolaihuat.com.sg
58.185.81.66	A	email.sutl.com
58.185.81.67	PTR	sutl.com
58.185.81.67	A+PTR	email.sutlcorp.com.sg
58.185.81.67	A+PTR	pop.sutlcorp.com.sg
58.185.81.68	PTR	mail.sutl.com.sg
58.185.81.68	A+PTR	exchange.sutlcorp.com.sg
58.185.81.68	A+PTR	smtp.sutlcorp.com.sg
58.185.81.74	A	sutlenvirontech.com
58.185.82.98	A+PTR	mail.bescon.com.sg
58.185.82.98	A	note03.komatsu.com.sg
58.185.82.99	A	smtp1.komatsu.com.sg
58.185.82.106	A+PTR	rigel-fw.rigel-group.com
58.185.82.106	A	qingfeng2018.com
58.185.82.138	A	mailmav2.starmedia.bz
58.185.82.138	A	mailmav2.expand.com.sg
58.185.82.138	A	mailmav2.mediaconnection.com.sg
58.185.82.249	A	ascenstar-cms.com
58.185.83.35	A	myisams.sais.edu.sg
58.185.83.46	A	saismailer.edu.sg
58.185.83.46	A	www.mystamford.edu.sg
58.185.83.46	A	mail.saismailer.edu.sg
58.185.83.51	A+PTR	mail.megatron.com.sg
58.185.83.51	A	ns1.megatron.com.sg
58.185.83.52	A	megatron.com.sg
58.185.83.68	A	mail.pcb.com.sg
58.185.83.68	A	mail.pcbxp.com
58.185.83.68	A	mail.discountstore.com.sg
58.185.83.77	A	starwood-careers.com
58.185.83.163	PTR	mail.hakuto.com.sg
58.185.83.163	PTR	server1.hakuto.com.sg