Robtex

Up: 206.172.40.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 206.172.40.0/23
Down right: 206.172.42.0/23
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
206.172.40.65	PTR	webmail.etfo.org
206.172.40.70	A+PTR	webmail.etfo.org
206.172.40.70	A	mail.etfo.org
206.172.40.74	A	docs.apexa.ca
206.172.40.99	A	mail.originalpartswarehouse.com
206.172.40.99	A	mail.lubesource.ca
206.172.40.99	A	mail1.kwtoronto.com
206.172.40.213	A	mailgate.columbiacollege.ca
206.172.40.214	A	mail.columbiacollege.bc.ca
206.172.40.217	A	ezproxy.columbiacollege.bc.ca
206.172.40.218	A	exch1.columbiacollege.bc.ca
206.172.40.220	A	student.columbiacollege.bc.ca
206.172.41.66	A+PTR	mail2.tecsys.com
206.172.41.66	A	vpn.tecsys.com
206.172.41.195	PTR	ns5.bbdo.com
206.172.41.196	A	dns1.cinram.com
206.172.41.210	A	mailgw1.cinram.com
206.172.41.227	PTR	ftp.pentamark.ca
206.172.41.227	PTR	ns1.singulink.com
206.172.41.227	PTR	ns1.singulink.com.41.172.206.in-addr.arpa
206.172.41.228	A+PTR	ns2.singulink.com
206.172.41.229	PTR	www.singulink.com
206.172.41.229	A	nulifelaserclinic.com
206.172.41.229	A	riverviewbingopalace.com
206.172.41.233	PTR	intnat.pentamark.ca
206.172.41.233	A	mail.bgle.ca
206.172.41.235	A	c1-web.net
206.172.41.235	A	c1web.org
206.172.41.236	PTR	ex1wo.pentamark.ca
206.172.41.236	A	mail.c1networx.com
206.172.41.249	PTR	mf1wo.pentamark.ca
206.172.42.5	PTR	spgdag.ca
206.172.42.5	PTR	flx.spgdag.ca
206.172.42.6	A+PTR	mail.dgig.ca
206.172.42.7	A+PTR	mailt1.dgdom.net
206.172.42.20	PTR	rt1.spgdag.ca
206.172.42.21	PTR	rt1.spgdag.ca
206.172.42.21	PTR	rt1x.spgdag.ca
206.172.42.34	A	accweb.gslb.dgdom.net
206.172.42.99	A	hartrodtcanada.com
206.172.42.100	A	mail.hartrodtcanada.com
206.172.42.102	A	morpheui.com
206.172.42.110	A	infinitetoolbox.com
206.172.42.230	PTR	tva-intranet.com
206.172.42.230	PTR	to101-mail.tva-intranet.com
206.172.42.230	PTR	toronto.tva-intranet.com