Robtex

Up: 64.43.232.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 64.43.232.0/23
Down right: 64.43.234.0/23
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
64.43.232.10	A+PTR	fw.usg.com
64.43.232.10	A+PTR	qa-web-001.usg.com
64.43.232.111	A+PTR	ns1.usg.com
64.43.232.112	A+PTR	ns2.usg.com
64.43.232.113	A	ns4.usg.com
64.43.232.114	A	ns5.usg.com
64.43.232.125	A+PTR	newalpha.usg.com
64.43.232.136	PTR	usgsubfloor.com
64.43.232.136	PTR	usgdesignstudio.com
64.43.232.136	PTR	api.usgdesignstudio.com
64.43.232.143	A	www.mycgc.ca
64.43.232.144	A	next.myusg.com
64.43.232.151	PTR	owa.usg.com
64.43.232.160	PTR	lw-co.com
64.43.232.160	PTR	brandsite.usg.com
64.43.232.160	A	usgdesignit.com
64.43.232.161	PTR	getmoldfacts.com
64.43.232.161	PTR	seismicceilings.com
64.43.232.161	PTR	www.getmoldfacts.com
64.43.232.164	A+PTR	usgceilingsolutions.com
64.43.232.164	A	usgtile.com
64.43.232.164	A	wallboard.net
64.43.232.165	PTR	hydrocal.biz
64.43.232.165	PTR	cas20.com
64.43.232.165	PTR	snowwhitefiller.com
64.43.232.174	A+PTR	eservices.usg.com
64.43.232.178	A+PTR	donngrid.com
64.43.232.178	PTR	fiberock.com
64.43.232.178	PTR	fortacrete.com
64.43.232.181	A+PTR	myusg.com
64.43.232.181	A	www.myusg.com
64.43.232.182	A+PTR	cms.myusg.com
64.43.232.183	PTR	mycgc.ca
64.43.232.183	A	www.mycgc.ca
64.43.232.188	A+PTR	next.usg.com
64.43.232.206	A+PTR	autodiscover.usg.com
64.43.232.206	A+PTR	owa.usg.com
64.43.232.206	PTR	autodiscover.usg.com.mx
64.43.233.21	PTR	mail02.usg.com
64.43.233.25	A+PTR	mail01.usg.com
64.43.233.25	A	prdc-smtp-02.usg.com
64.43.234.111	A	ns3.usg.com
64.43.234.113	A	ns6.usg.com
64.43.234.149	A	eservicests.usg.com
64.43.234.149	A	eservicessb.usg.com
64.43.234.149	A	eservicestr.usg.com
64.43.234.160	A+PTR	eservicesit.usg.com
64.43.234.161	A+PTR	eservicesat.usg.com
64.43.234.162	A	eservicesqa.usg.com
64.43.235.25	A+PTR	mail05.usg.com
64.43.235.25	A+PTR	npdc-smtp-01.usg.com