Robtex

Up: 213.245.2.0/23
Can't show all results, try to descend to a more specific CIDR
Down left: 213.245.2.0/25
Down right: 213.245.2.128/25
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
213.245.2.1	A	gw.mail.completel.net
213.245.2.2	PTR	mx.mail.completel.net
213.245.2.2	A	relay1.dcsautomotive.fr
213.245.2.2	A	mailhost.ferco.fr
213.245.2.3	PTR	smtp.mail.completel.net
213.245.2.3	A	smtp.ifip.asso.fr
213.245.2.3	A	smtp.completel.fr
213.245.2.4	A+PTR	smtpav.mail.completel.net
213.245.2.4	A	securesmtp.completel.net
213.245.2.5	A+PTR	mm.mail.completel.net
213.245.2.5	A	massmail.completel.net
213.245.2.10	PTR	admin.mail.completel.net
213.245.2.17	A+PTR	mx5.mail.completel.net
213.245.2.27	A+PTR	av7.mail.completel.net
213.245.2.32	A+PTR	smtp1.mail.completel.net
213.245.2.33	A+PTR	smtp2.mail.completel.net
213.245.2.34	A+PTR	smtp3.mail.completel.net
213.245.2.35	A+PTR	smtp4.mail.completel.net
213.245.2.36	PTR	smtp2.mail.completel.net
213.245.2.36	A	smtp5.mail.completel.net
213.245.2.42	PTR	smtp11.mail.completel.net
213.245.2.45	PTR	fb2.mail.completel.net
213.245.2.46	PTR	server46.mail.completel.net
213.245.2.47	PTR	server47.mail.completel.net
213.245.2.47	A	fb1.mail.completel.net
213.245.2.49	PTR	av2.mail.completel.net
213.245.2.56	A	av20.mail.completel.net
213.245.2.72	A+PTR	server72.mail.completel.net
213.245.2.92	A+PTR	server92.mail.completel.net
213.245.2.128	PTR	213-245-2-128.rev.numericable.fr