dns1.telstra.net has one IP number , which also has a corresponding reverse pointer. t.audns.net.au point to the same IP. id.au, asn.au, net.au, edu.au, com.au and at least 100 other hosts use this as a nameserver. telstra.net is a domain controlled by four nameservers. Two of them are on the same IP network. Incoming mail for telstra.net is handled by two mailservers at telstra.net themselves. They are on the same IP network. dns1.telstra.net is hosted on a server in Australia.
APNIC-AP Asia Pacific Network Information Center, Pty. Ltd. Regional Internet Registry for the Asia-Pacific Region Level 1 - 33 Park Road. Milton QLD 4064 Australia