Robtex

Up: 81.23.88.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 81.23.92.0/23
Down right: 81.23.94.0/23

IP	Type	Hostname
81.23.92.14	A	esercinux27.datasiel.net
81.23.92.44	A+PTR	smail1.datasiel.net
81.23.92.44	A	mx1.datasiel.net
81.23.92.45	A+PTR	smail3.datasiel.net
81.23.92.45	A	mx1.datasiel.net
81.23.92.46	A+PTR	smail4.datasiel.net
81.23.92.46	A	mx1.datasiel.net
81.23.92.48	A	deposito.datasiel.net
81.23.92.51	A+PTR	smail1.datasiel.net
81.23.92.52	A+PTR	smail2.datasiel.net
81.23.92.52	A	mx1.datasiel.net
81.23.92.53	A+PTR	smail1.liguriadigitale.it
81.23.92.53	A	mx1.liguriadigitale.it
81.23.92.54	PTR	smail2.liguriadigitale.it
81.23.92.54	A	mx1.liguriadigitale.it
81.23.92.55	PTR	smail3.liguriadigitale.it
81.23.92.101	A+PTR	ns1.datasiel.net
81.23.92.102	A+PTR	ns2.datasiel.net
81.23.93.114	A+PTR	drive.liguriadigitale.it
81.23.93.204	PTR	smail03.liguriadigitale.it
81.23.93.205	PTR	smail04.liguriadigitale.it