go
mail.makro.gr has one IP number , but the reverse is diphda.makro.gr. diphda.makro.gr cnames to this hostname. ns.makro.gr point to the same IP. makro.gr is a domain controlled by three nameservers. All of them are on different IP networks. Incoming mail for makro.gr is handled by one mailserver at metro.info. mail.makro.gr is hosted on a server in Germany even though the hostname implies Greece.

mail.makro.gr
a records
 
+ 194.99.224.132 194.99.224.0/22 AS35465 diphda.makro.gr
+ --- diphda.makro.gr

makro.gr
ns-soa records
 
+   AS?  
+ ---  
ns records
ns.metro-ag.com
+ 194.156.63.4 194.156.60.0/22 AS23985 -
+ --- -
ns.metro.de
+ 164.61.210.4 164.61.0.0/16 AS8569 -
ns.metro.info
+ 164.139.12.4 164.139.12.0/22 AS39290 -
mx records
smtp.metro.info
+ 164.61.205.160 164.61.0.0/16 AS8569  
+ ---  
ip numbers of host
194.99.224.132
ptrs of ip numbers
diphda.makro.gr
ip numbers using ptr to this host
217.19.87.236
hostnames sharing ip with a-records
ns.makro.gr
hostnames pointing here by cname
diphda.makro.gr