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Reverse DNS Delegation

Reverse DNS allows an Internet host to map an IP address to a hostname. For example, the IP address of our Melbourne border router, 203.63.80.17, is mapped in Reverse DNS to bdr1.mel.connect.com.au. This is in contrast to Forward DNS, which would map the name to the IP address.

You can configure Reverse DNS by having the Reverse DNS zone for your network delegated to your nameserver. Reverse DNS zones reside in the in-addr.arpa domain, and work in a similar way to Forward DNS zones. Zone names consist of the Network Address - with octets listed in reverse order - followed by in-addr.arpa. For example, the Reverse DNS zone for the network 203.63.107 is 107.63.203.in-addr.arpa.

Before attempting to configure Reverse DNS, you should have a good familiarity with the way DNS works, and with your nameserver software. For more information on DNS, see the Introduction to DNS on this site.


Reverse Delegation of IP Ranges assigned by AAPT

If you're using IP space which has been assigned to you by AAPT (generally addresses in the range 203.63.0.0 - 203.63.255.255, and 210.8.0.0 - 210.11.0.0), you should request Reverse Delegation by emailing hostmaster@connect.com.au.

Please include the following information:

For example:

To: hostmaster@connect.com.au
From: zoe@example.com
Subject: Reverse Delegation for 192.0.2.0/24

Dear connect Hostmaster,

Please configure reverse delegation for the network
192.0.2.0/24, which is routed to our connection. The
details are as follows:

Company Name: Foo Networks Australia
Customer ID:  130123
Contact:      Zoe Holt6, 03 9696 9696
Network:      203.63.107/24 (2.0.192.in-addr.arpa.)

Primary Name Server:   ns1.example.com. (192.0.2.1)
Secondary Name Server: ns2.example.com. (192.0.2.2)

Thankyou,

Zoe Holt
Technical Director

Please ensure that your Primary and Secondary name servers are configured before you send your request.

After sending your email, you should receive an automated response confirming your request. You should receive a second email after our hostmaster has made the necessary changes.


Reverse DNS for Classless IP Allocations

AAPT generally does not perform reverse delegation for networks smaller than a /24 or Class C network. If you require reverse resolution for IP addresses in an allocation smaller than a /24 network, please email hostmaster@connect.com.au with the details of the IP address and hostname pairs you require.

For example:

To: hostmaster@connect.com.au
From: zoe@example.com
Subject: Reverse DNS Entries in 192.0.2

Dear AAPT Hostmaster,

Could you please add reverse DNS records for our mail and DNS
servers. The addresses we require are as follows:

192.0.2.18  -  ftp.example.com.
192.0.2.19  -  mail.example.com.

Thankyou,

Zoe Holt
Technical Director

You should receive an automated response confirming your request. Please note that if AAPT also hosts your own forward domain, you will also need to request addition of the matching forward DNS entries.

If you specifically want to administer DNS yourself for a block that is smaller than a /24, you can follow the guidelines provided in RFC 2317 to set up DNS for the portion allocated to you. Then email hostmaster@connect.com.au with the details. For example:

IP Block: 192.0.2.0/25
Zone:     0-25.2.0.192.in-addr.arpa.
Primary:  ns1.example.com. (192.0.2.3)
Please configure AAPT nameservers yarrina and warrane
as secondaries for this zone and add the appropriate CNAME
records as described in RFC 2317.

Reverse DNS for IP Ranges not assigned by AAPT

If you are using address space that was not assigned to you by AAPT, you should contact the body who assigned the addresses to you.

Portable address space in Australia is generally assigned by APNIC. You can request Reverse Delegation from APNIC using this form.


Further Information and Help

AAPT Recommends DNS & BIND (O'Reilly and Associates). There is also an Introduction to DNS on this site.

If you have any enquiries relating to delegation procedures, or would like to enquire about the progress of a request, please Contact Support.


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