Robtex

Up: 81.31.160.0/23
Can't show all results, try to descend to a more specific CIDR
Down left: 81.31.160.0/25
Down right: 81.31.160.128/25
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
81.31.160.1	A	router.sharif.ac.ir
81.31.160.10	PTR	ge0-10.internal.sf-gw.sharif.ir
81.31.160.12	PTR	access-gw.sharif.edu
81.31.160.26	PTR	web-cache.sharif.edu
81.31.160.26	A	webcache.sharif.ir
81.31.160.30	PTR	lpb0.core-router.sharif.ir
81.31.160.34	A+PTR	ns1.sharif.ir
81.31.160.34	A	ns1.sharif.ac.ir
81.31.160.34	A	pars.sharif.ir
81.31.160.35	A+PTR	homa.sharif.ir
81.31.160.35	A	homa.sharif.ac.ir
81.31.160.35	A	smtp1.sharif.ir
81.31.160.37	A	mtl.sharif.edu
81.31.160.39	PTR	sina.sharif.ir
81.31.160.39	A	www.sina.sharif.edu
81.31.160.39	A	icpc.sharif.edu
81.31.160.41	A+PTR	sepehr.sharif.ir
81.31.160.41	A	sepehr.sharif.ac.ir
81.31.160.41	A	axlegear.com
81.31.160.42	A+PTR	sepand.sharif.ir
81.31.160.43	A+PTR	sahand.sharif.ir
81.31.160.43	A	smtp.sharif.ir
81.31.160.43	A	smtp2.sharif.ir
81.31.160.44	A+PTR	arvand.sharif.ir
81.31.160.44	A	lubnet.cn
81.31.160.45	A+PTR	kamand.sharif.ir
81.31.160.46	A+PTR	mx1.sharif.ir
81.31.160.46	A	mx1.sharif.ac.ir
81.31.160.46	A	mx1.sharif.edu
81.31.160.51	PTR	www.sharif.ir
81.31.160.51	A	civil.sharif.ir
81.31.160.51	A	srrc.sharif.ir
81.31.160.52	PTR	mehr.sharif.ir
81.31.160.52	A	mehr.sharif.edu
81.31.160.52	A	aria.sharif.edu
81.31.160.54	A	ns.quantcan.ir
81.31.160.57	A	2013-08-29.u3wan.pw
81.31.160.57	A	el.sharif.ac.ir
81.31.160.57	A	esharif.ir
81.31.160.59	A	mail.smartdelivery.nl
81.31.160.59	A	extsvc-01.thedailysystem.com
81.31.160.59	A	www.godebthelpalerts.com
81.31.160.129	PTR	ge8-48.vl7.core-router.sharif.edu
81.31.160.130	A+PTR	amin.sharif.edu
81.31.160.132	A	www.bonyad.ir
81.31.160.132	A	bonyad.ir
81.31.160.133	A+PTR	mx3.sharif.edu
81.31.160.133	A	mx3.sharif.ac.ir
81.31.160.133	A	mx3.sharif.ir
81.31.160.134	A	mail.edu.sharif.ir
81.31.160.134	A	pc.bonyad.ir
81.31.160.134	A	mx1.farayan.ir
81.31.160.139	A+PTR	darkstar.sharif.edu
81.31.160.139	A	mail.xiaoxin-fire.com
81.31.160.140	A	palistine.com
81.31.160.140	A	mohsen2.sharif.ir
81.31.160.141	A+PTR	sutcc.sharif.ir
81.31.160.141	A	thecustomaccessoriesgroup.com
81.31.160.141	A	sutcc.sharif.ac.ir