Robtex

Up: 199.21.80.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 199.21.84.0/23
Down right: 199.21.86.0/23
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
199.21.84.2	PTR	x.199.21.84.web-pass.com
199.21.84.2	A	dhcp.199newmontgomery.web-pass.com
199.21.84.13	PTR	x.199.21.84.web-pass.com
199.21.84.15	PTR	x.199.21.84.web-pass.com
199.21.84.15	A	nathankonopinski.com
199.21.84.33	PTR	x.199.21.84.web-pass.com
199.21.84.33	A	sfo.mindcast.net
199.21.84.126	PTR	x.199.21.84.web-pass.com
199.21.84.126	A	dhcp.650chestnut.web-pass.com
199.21.84.130	PTR	x.199.21.84.web-pass.com
199.21.84.130	A	dhcp.88townsend.web-pass.com
199.21.84.190	PTR	x.199.21.84.web-pass.com
199.21.84.190	A	dhcp.1438green.web-pass.com
199.21.84.226	PTR	x.199.21.84.web-pass.com
199.21.84.226	A	dhcp.788minna.web-pass.com
199.21.85.18	PTR	x.199.21.85.web-pass.com
199.21.85.18	A	dhcp.871turk.web-pass.com
199.21.85.34	PTR	x.199.21.85.web-pass.com
199.21.85.34	A	dhcp.423seventh.web-pass.com
199.21.85.228	PTR	x.199.21.85.web-pass.com
199.21.86.50	PTR	x.199.21.86.web-pass.com
199.21.86.50	A	nat2.dlitz.net
199.21.86.67	PTR	x.199.21.86.web-pass.com
199.21.86.67	A	ts.cooper.com
199.21.86.69	A+PTR	spam.cooper.com
199.21.86.69	A	client.cooper.com
199.21.86.69	A	tempspam.cooper.com
199.21.86.70	PTR	client.cooper.com
199.21.86.154	PTR	x.199.21.86.web-pass.com
199.21.86.154	A	blackhole.web-pass.com
199.21.86.231	PTR	x.199.21.86.web-pass.com
199.21.87.58	PTR	x.199.21.87.web-pass.com
199.21.87.62	PTR	x.199.21.87.web-pass.com
199.21.87.62	A	dhcp.1121fortieth.web-pass.com
199.21.87.140	PTR	x.199.21.87.web-pass.com
199.21.87.140	A	resolver1-sf.webpass.net
199.21.87.142	PTR	x.199.21.87.web-pass.com
199.21.87.142	A	vpn1-sf.webpass.net
199.21.87.170	PTR	ns2.webpass.net
199.21.87.170	PTR	ns.365main.web-pass.com
199.21.87.170	A+PTR	ns.365main.webpass.net
199.21.87.180	PTR	x.199.21.87.web-pass.com
199.21.87.180	A	server01.ccholdings.com
199.21.87.180	A	ccholdings.com