Robtex

Up: 216.136.0.0/23
Can't show all results, try to descend to a more specific CIDR
Down left: 216.136.1.0/25
Down right: 216.136.1.128/25
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
216.136.1.19	A	ualswebservices.united.com
216.136.1.36	PTR	mileageplusheadliners.com
216.136.1.36	A+PTR	ualmileageplus.com
216.136.1.36	PTR	store.ualmileageplus.com
216.136.1.37	A	smartphone-preview.united.com
216.136.1.38	A	webservices.continental.com
216.136.1.46	PTR	ualaki-bigpanda-csmc-apicalls.united.com
216.136.1.49	A	autopilot.united.com
216.136.1.52	A	webservices.united.com
216.136.1.55	A	offers.united.com
216.136.1.56	A	alexa.united.com
216.136.1.57	A	iot.united.com
216.136.1.59	A	sna.coair.com
216.136.1.65	A+PTR	offerspreview.united.com
216.136.1.67	PTR	location.united.com
216.136.1.67	A	cars.united.com
216.136.1.74	A	partnerservices.united.com
216.136.1.76	A+PTR	wftest.united.com
216.136.1.77	A	mobile-preview.united.com
216.136.1.79	A	uaschedulep.united.com
216.136.1.80	A+PTR	uaschedules.united.com
216.136.1.81	A	schedulep.united.com
216.136.1.82	A+PTR	schedules.united.com
216.136.1.85	A+PTR	m.united.com
216.136.1.85	A+PTR	qamobile.united.com
216.136.1.87	A	uaflightrangep.united.com
216.136.1.88	A	uaflightranges.united.com
216.136.1.92	A+PTR	erespassrider.ual.com
216.136.1.92	A	employeerespss.coair.com
216.136.1.97	A+PTR	partnerservices2.united.com
216.136.1.106	A	smartphone-test.united.com
216.136.1.107	A+PTR	origin-hub.united.com
216.136.1.107	A+PTR	pct-ext-dpapi.ual.com
216.136.1.107	A+PTR	unitedhub.com
216.136.1.110	A	mobilecontents.united.com
216.136.1.112	A+PTR	apigw.united.com
216.136.1.113	A+PTR	apiauth.united.com
216.136.1.118	A+PTR	o-prodperf.united.com
216.136.1.122	A	wfbeta.united.com
216.136.1.139	A+PTR	media.united.com
216.136.1.144	A+PTR	csmc.beta.api.united.com
216.136.1.150	PTR	www.tmcaccess.com
216.136.1.150	PTR	www.ual.com
216.136.1.150	PTR	unitedairlines.ca
216.136.1.151	A	origin-xml.united.com
216.136.1.152	A	origin-preview.united.com
216.136.1.153	A	ucomapi.united.com
216.136.1.153	A	activeagent.united.com
216.136.1.155	A+PTR	n6jq0-origin-walletservices.united.com
216.136.1.158	A	xml2.united.com
216.136.1.159	A	gds.united.com
216.136.1.161	A	unitedperksplus.united.com
216.136.1.171	PTR	ualaki-csmc.preprod.api.united.com
216.136.1.171	A	csmc.preprod.api.united.com
216.136.1.178	A+PTR	erespreview.united.com
216.136.1.181	A+PTR	origin-beta.united.com
216.136.1.185	A+PTR	partnergw-csmc.united.com
216.136.1.186	A+PTR	partnerauth-csmc.united.com
216.136.1.188	A+PTR	beta.cas.ual.com
216.136.1.189	A+PTR	beta.fom.ual.com
216.136.1.196	A+PTR	wifi.united.com
216.136.1.212	A+PTR	prodperf.csshis.ual.com
216.136.1.213	A+PTR	prodperf.cas.ual.com
216.136.1.213	A+PTR	eres.app.auth.united.com
216.136.1.214	A+PTR	prodperf.sss.ual.com
216.136.1.214	A+PTR	apicauthsso-saml.united.com
216.136.1.215	A+PTR	prodperf.fom.ual.com
216.136.1.215	A+PTR	apicauthsso-openid.united.com