go
server6.subsys.no has one IP number , which also has a corresponding reverse pointer. post.subsys.no point to the same IP. nir.no, upn.no, 5min.no, m4tv.com, kjemi.no and at least 100 other hosts use this as a mailserver. subsys.no is a domain controlled by two nameservers at subsys.no themselves. They are on different IP networks. Incoming mail for subsys.no is handled by one mailserver also at subsys.no. subsys.no has one IP number , but the reverse is server4.subsys.no. server6.subsys.no is hosted on a server in Norway.

server6.subsys.no
a records
 
+ 85.19.71.170 85.19.0.0/16 AS3292 -
+ --- -

subsys.no
a records
 
+ 85.19.71.162 85.19.0.0/16 AS3292 server4.subsys.no
+ --- server4.subsys.no
ns-soa records
ns1.subsys.no
+ 85.19.71.162 85.19.0.0/16 AS3292 server4.subsys.no
+ --- server4.subsys.no
ns records
ns1.subsys.no
+ 85.19.71.162 85.19.0.0/16 AS3292 server4.subsys.no
+ --- server4.subsys.no
ns2.subsys.no
+ 209.20.80.91 209.20.64.0/19 AS12200 server3.subsys.no
+ --- server3.subsys.no
mx records
server6.subsys.no
+ 85.19.71.170 85.19.0.0/16 AS3292 -
+ --- -
ip numbers of host
85.19.71.170
ptrs of ip numbers
server6.subsys.no
ip numbers using ptr to this host
85.19.71.170
hostnames sharing ip with a-records
post.subsys.no
domains using this as mailserver
5min.no
acimsvg.com
albatross-ohoi.net
andreasandersen.net
aolresearch.org
aoluniversity.org
artofliving.no
artoflivingresearch.org
atharonrpg.com
bardexa.com
bjornar.no
byggkeramikkforeningen.no
chopperclub-norway.com
citahagen.com
difsoftware.com
dj-erlendl.com
djdontomaso.com
ebascripts.com
ecalision.com
einarsen.net
eksplisitt.net
elizabedzeti.com
elmannen.net
essemeff.com
famotorsport.com
filmantrop.net
finnmarksfluer.net
forsaken-lands.net
fossefallet.net
framnes.vgs.no
frode-marit.net
funkyplumbo.com
gammelhorken.com
gangso.net
garborg.net
giltvedt.net
gjerull.net
grimholt.net
haarstad.net
hunting-pride.com
ianbel.com
imagasin.no
ipcomics.net
jahraw.com
jantzen.no
japansk-spisshund.net
jazzaggression.com
johnnykreutz.com
kakofon.com
kammermusikk.net
kardemommehuset.com
kevinjh.net
kimjoar.net
kjemi.no
knappenforeningen.no
kreft06.no
kriik.com
kuntigi.net
langegaarden.no
lars-olsen.net
lifefrombelow.com
linrk.net
m4tv.com
matsj.net
midling.net
mikaelaanestad.com
nettintro.no
ngrenland.net
nir.no
nodenet.com
norplatoon.net
nortabs.net
norwaynature.com
norwegianpirates.net
nuffe.net
opensource-notebook.com
partytelt.net
pmedia.no
pondus.net
ravnanger.net
rent-a-wreck.dk
residence.no
rodtangen.com
roskva.net
runarolsen.net
rushprint.no
scooternorge.no
selassierecords.com
sentrumkirken.net
servicenett.no
sickel.net
signalfestival.net
skandinavisk-bureau.com
skartland.net
skriblerier.net
sladris.com
sommerfjosbakken.net
songcans.com
speilvendt.com
stakland.com
subsys.no
sundetwestern.com
svalbardflora.net
svolk.net
sydensol.com
teamgym.net
tetova.net
the-boogiemen-inc.com
tinydynamite.com
tromsoby.no
trondsaether.com
tuxic.net
tylden.net
ulvefaret.net
unbornchikken.com
upn.no
veidahl.net
womensvoiceweb.com
zapffe.com
zealousmind.com
domains using this as mailserver under another name
spillegal.no