go
drs-dns-ext.bom.gov.au has one IP number , which also has a corresponding reverse pointer. bom.gov.au, cawcr.gov.au, ho.bom.gov.au, nt.bom.gov.au, nsw.bom.gov.au and at least six other hosts use this as a nameserver. bom.gov.au is a domain controlled by three nameservers. All of them are on different IP networks. Incoming mail for bom.gov.au is handled by two mailservers at bom.gov.au themselves. They are on different IP networks. drs-dns-ext.bom.gov.au is hosted on a server in Australia.

drs-dns-ext.bom.gov.au
a records
 
+ 134.178.253.126 134.178.128.0/17 AS23667 -
+ --- -

bom.gov.au
ns-soa records
ho-dns-ext.bom.gov.au
+ 134.178.63.126 134.178.0.0/17 AS23667 -
+ --- -
ns records
ns1.unimelb.edu.au
+ 128.250.20.2 128.250.0.0/16 AS10148 -
+ --- -
drs-dns-ext.bom.gov.au
+ 134.178.253.126 134.178.128.0/17 AS23667 -
ho-dns-ext.bom.gov.au
+ 134.178.63.126 134.178.0.0/17 AS23667 -
mx records
drs-mailfilter2.bom.gov.au
+ 134.178.253.184 134.178.128.0/17 AS23667  
+ ---  
ho-mailfilter2.bom.gov.au
+ 134.178.63.184 134.178.0.0/17 AS23667  
ip numbers of host
134.178.253.126
ptrs of ip numbers
drs-dns-ext.bom.gov.au
ip numbers using ptr to this host
134.178.253.126
domains using this as nameserver
1.178.134.in-addr.arpa
130.178.134.in-addr.arpa
178.134.in-addr.arpa
226.178.134.in-addr.arpa
234.178.134.in-addr.arpa
90.178.134.in-addr.arpa
bom.gov.au
cawcr.gov.au
ho.bom.gov.au
nsw.bom.gov.au
nt.bom.gov.au
used as nameserver but missing in parent delegation
nsw.bom.gov.au
nt.bom.gov.au
used as nameserver but missing in zone
ho.bom.gov.au