Robtex

Up: 64.4.48.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 64.4.48.0/23
Down right: 64.4.50.0/23
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
64.4.48.1	A+PTR	ns2-01.azure-dns.net
64.4.48.1	A	ns1prod.6913.azuredns-prd.info
64.4.48.1	A	ns2prod.20932.azuredns-prd.org
64.4.48.2	PTR	ns2-02.azure-dns.net
64.4.48.3	PTR	ns2-03.azure-dns.net
64.4.48.4	A+PTR	ns2-04.azure-dns.net
64.4.48.4	A	ns2prod.111.azuredns-prd.org
64.4.48.4	A	ns2prod.172.azuredns-prd.org
64.4.48.5	PTR	ns2-05.azure-dns.net
64.4.48.6	PTR	ns2-06.azure-dns.net
64.4.48.7	PTR	ns2-07.azure-dns.net
64.4.48.8	A+PTR	ns2-08.azure-dns.net
64.4.48.8	A	ns4.hpservice.com.hk
64.4.48.8	A	ns2prod.5611.azuredns-prd.org
64.4.48.9	PTR	ns2-09.azure-dns.net
64.4.48.10	PTR	ns2-10.azure-dns.net
64.4.48.201	A+PTR	ns2-201.azure-dns.net
64.4.48.201	A	ns2prod.arpa-201.azuredns-prd.org
64.4.48.201	A	ns2prod.6403.azuredns-prd.org
64.4.48.202	PTR	ns2-202.azure-dns.net
64.4.48.203	PTR	ns2-203.azure-dns.net
64.4.48.204	A+PTR	ns2-204.azure-dns.net
64.4.48.205	PTR	ns2-205.azure-dns.net
64.4.48.205	A	ns2-205.botframework.com.msftnet.org
64.4.48.205	A	ns2-205.skype.com.msftnet.org
64.4.48.208	A+PTR	ns2-208.azure-dns.net
64.4.48.208	A	hensconsulting.com
64.4.48.208	A	nsp2.bdm.microsoftonline.com
64.4.48.221	A+PTR	ns2-221.azure-dns.net
64.4.48.221	A	ns2.sharepoint.com.msftnet.org
64.4.48.224	A+PTR	ns2-224.azure-dns.net
64.4.48.224	A	ns2prod.122.azuredns-prd.org
64.4.48.224	A	ns2prod.41087.azuredns-prd.org
64.4.48.225	A+PTR	ns2-225.azure-dns.net
64.4.50.111	A	internal.ap.messenger.msn.com.nsatc.net
64.4.50.139	A	msnbot-64-4-50-139.search.msn.com
64.4.50.140	A	msnbot-64-4-50-140.search.msn.com
64.4.50.141	A+PTR	msnbot-64-4-50-141.search.msn.com
64.4.50.143	A	msnbot-64-4-50-143.search.msn.com
64.4.50.148	A	msnbot-64-4-50-148.search.msn.com
64.4.50.149	A	msnbot-64-4-50-149.search.msn.com
64.4.50.150	A+PTR	msnbot-64-4-50-150.search.msn.com
64.4.50.151	A	msnbot-64-4-50-151.search.msn.com
64.4.50.152	A	msnbot-64-4-50-152.search.msn.com
64.4.50.153	A	msnbot-64-4-50-153.search.msn.com
64.4.50.158	A	msnbot-64-4-50-158.search.msn.com
64.4.50.159	PTR	msnbot-64-4-50-159.search.msn.com
64.4.50.164	A	msnbot-64-4-50-164.search.msn.com
64.4.50.167	A	msnbot-64-4-50-167.search.msn.com
64.4.50.168	A	msnbot-64-4-50-168.search.msn.com
64.4.50.170	A	msnbot-64-4-50-170.search.msn.com
64.4.50.171	A	msnbot-64-4-50-171.search.msn.com
64.4.50.173	A	msnbot-64-4-50-173.search.msn.com
64.4.50.176	A	msnbot-64-4-50-176.search.msn.com
64.4.50.177	A	msnbot-64-4-50-177.search.msn.com
64.4.50.184	A	msnbot-64-4-50-184.search.msn.com
64.4.50.207	PTR	msnbot-64-4-50-207.search.msn.com