Robtex

Up: 148.204.138.0/23
Can't show all results, try to descend to a more specific CIDR
Down left: 148.204.139.0/25
Down right: 148.204.139.128/25
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
148.204.139.1	PTR	pc-139-001.upiig.ipn.mx
148.204.139.1	PTR	www.upiig.saes.ipn.mx
148.204.139.1	PTR	www.saes.upiig.ipn.mx
148.204.139.6	PTR	pc-139-006.upiig.ipn.mx
148.204.139.6	A+PTR	www.siisa.upiig.ipn.mx
148.204.139.6	A	siisa.upiig.ipn.mx
148.204.139.14	PTR	pc-139-014.upiig.ipn.mx
148.204.139.14	PTR	www.celex.upiig.ipn.mx
148.204.139.14	PTR	www.vehiculos.upiig.ipn.mx
148.204.139.100	PTR	pc-139-100.upiig.ipn.mx
148.204.139.100	A+PTR	www.sao.upiig.ipn.mx
148.204.139.100	A	sao.upiig.ipn.mx
148.204.139.167	PTR	pc-139-167.upiig.ipn.mx