Robtex

Up: 77.238.160.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 77.238.164.0/23
Down right: 77.238.166.0/23

IP	Type	Hostname
77.238.164.8	PTR	unknown-77-238-164-x.yahoo.com
77.238.164.8	A	b.dp.yieldmanager.net
77.238.164.9	PTR	ch1-da1002.dap.ch1.yahoo.com
77.238.164.9	A	b.dp.yieldmanager.net
77.238.164.72	PTR	unknown-77-238-164-x.yahoo.com
77.238.164.248	PTR	ch1-da1000.dap.ch1.yahoo.com
77.238.164.248	A	b.dp.yieldmanager.net
77.238.164.249	PTR	ch1-da1001.dap.ch1.yahoo.com
77.238.164.249	A	b.dp.yieldmanager.net
77.238.167.255	PTR	unknown-77-238-167-x.yahoo.com