Robtex

Up: 5.57.20.0/22
Can't show all results, try to descend to a more specific CIDR
Down left: 5.57.20.0/24
Down right: 5.57.21.0/24
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
5.57.20.8	A	proxy-gw-l.booking.com
5.57.20.11	A	vpn2.booking.com
5.57.20.11	A	vpn.booking.com
5.57.20.24	A	gw1gp1.booking.com
5.57.20.25	A	gw1gp2.booking.com
5.57.20.26	A	gw1gp3.booking.com
5.57.20.29	A	gw2gp5.booking.com
5.57.20.36	A+PTR	webconf.booking.com
5.57.20.72	A	outlook.booking.com
5.57.20.80	A	mgp.booking.com
5.57.20.128	A	google.itspublic.booking.com
5.57.20.128	A	federate.itspublic.booking.com
5.57.20.128	A	google.booking.com
5.57.20.136	A+PTR	mercury-mp201.booking.com
5.57.20.136	A	mercury.booking.com
5.57.20.142	PTR	xmpp-l2.booking.com
5.57.20.142	A	apidev.itspublic.booking.com
5.57.20.143	A	webtop.itspublic.booking.com
5.57.20.145	A	crx.internal.itspublic.booking.com
5.57.20.147	A	idp.itspublic.booking.com
5.57.20.147	A	youat.booking.com
5.57.20.147	A	globalgurusso.booking.com
5.57.20.151	A	jira.itspublic.booking.com
5.57.20.153	A	api.voice.itspublic.booking.com
5.57.20.160	A+PTR	prodout-l.booking.com
5.57.20.166	A+PTR	mail-lhr4-214.booking.com
5.57.20.166	A	mercury.booking.com
5.57.20.166	A	ns0.activehotels.net
5.57.20.167	PTR	mail-lhr4-213.booking.com
5.57.20.167	A	mercury.booking.com
5.57.20.167	A	ns1.activehotels.net
5.57.20.176	A+PTR	mail-me5.booking.com
5.57.20.177	A+PTR	mail-me6.booking.com
5.57.20.177	A	engine.booking.com
5.57.20.177	A	mailer.booking.com
5.57.20.178	A+PTR	mx201.booking.com
5.57.20.178	A	mx5.booking.com
5.57.20.179	A+PTR	mx202.booking.com
5.57.20.179	A	mx6.booking.com
5.57.20.182	A+PTR	mail-out5.booking.com
5.57.20.186	A+PTR	sg-l-mail-9.booking.com
5.57.20.188	A+PTR	sg-l-mail-11.booking.com
5.57.20.190	A+PTR	mail-me7.booking.com
5.57.20.190	A	engine.booking.com
5.57.20.190	A	mailer.booking.com
5.57.20.192	A+PTR	mail-rv5.booking.com
5.57.20.192	A	engine.booking.com
5.57.20.192	A	mailer.booking.com
5.57.20.193	A+PTR	mail-rv6.booking.com
5.57.20.194	A	mail-rv7.booking.com
5.57.20.195	A+PTR	mx210.booking.com
5.57.20.201	A+PTR	mx211.booking.com
5.57.20.201	A	mx3.booking.com
5.57.20.204	A+PTR	mercury-mp202.booking.com
5.57.20.204	A	mercury.booking.com
5.57.20.207	A	mx212.booking.com
5.57.21.1	A+PTR	nat-gw-a.booking.com
5.57.21.7	A	lraams4.booking.com
5.57.21.8	A+PTR	proxy-gw-a.booking.com
5.57.21.11	A+PTR	vpn.booking.com
5.57.21.23	A	gw2gp6.booking.com
5.57.21.24	A	gw2gp1.booking.com
5.57.21.26	A	gw2gp3.booking.com
5.57.21.71	A	autodiscover.booking.com
5.57.21.80	A	gp.booking.com
5.57.21.81	A	lgp.booking.com
5.57.21.129	A+PTR	proxy-out-a.booking.com
5.57.21.130	A+PTR	mercury-mp101.booking.com
5.57.21.130	A	mercury.booking.com
5.57.21.136	A	mail.booking.com
5.57.21.136	A	webmail.booking.com
5.57.21.136	A	epprotect.booking.com
5.57.21.137	A+PTR	xmpp-a.booking.com
5.57.21.138	A	fort.booking.com
5.57.21.140	A+PTR	mercury-mp102.booking.com
5.57.21.140	A	mercury.booking.com
5.57.21.145	A	itsndes.itspublic.booking.com
5.57.21.149	A	workforce.booking.com
5.57.21.155	A	jtest.itspublic.booking.com
5.57.21.160	A+PTR	prodout-a.booking.com
5.57.21.166	A+PTR	mercury-mp103.booking.com
5.57.21.166	A	mercury.booking.com
5.57.21.167	A+PTR	mercury-mp104.booking.com
5.57.21.167	A	mercury.booking.com
5.57.21.176	A+PTR	mail-me8.booking.com
5.57.21.177	A+PTR	mail-me9.booking.com
5.57.21.178	A+PTR	mx103.booking.com
5.57.21.179	A+PTR	mx104.booking.com
5.57.21.179	A	mx8.booking.com
5.57.21.183	A	mail-out9.booking.com
5.57.21.186	A+PTR	sg-a-mail-9.booking.com
5.57.21.190	A+PTR	mail-me10.booking.com
5.57.21.191	A	mail-out10.booking.com
5.57.21.192	A	mail-rv8.booking.com
5.57.21.193	A	mail-rv9.booking.com
5.57.21.194	A	mail-rv10.booking.com
5.57.21.195	A+PTR	mx110.booking.com
5.57.21.195	A	mx9.booking.com
5.57.21.204	A+PTR	mx101.booking.com
5.57.21.205	A	itswebhook.itspublic.booking.com
5.57.21.205	A	video.booking.com
5.57.21.206	A	customerservice.itspublic.booking.com
5.57.21.206	A	customerservice.booking.com
5.57.21.208	A+PTR	mx111.booking.com
5.57.21.211	A	jamf.itspublic.booking.com
5.57.21.221	A	ovpn.c.booking.com