This post is only relevant to people that live in Australia mainly around Perth - international readers please ignore.
The popular DNS server dns.iinet.net.au (18.104.22.168) has been used by many IT professionals in Perth for years due to its fast response times and massive cache!
However as of December 2009 iiNet has configured ACL's on this DNS server to only allow people from iiNet IP Addresses to use it. Many other ISP's lock down their DNS server to only their IP ranges as well such as Amnet (another popular Perth ISP).
I found this out as one of my sites was connected using Internode running a bind9 server that forwarded DNS requests to iiNet. If iiNet failed it would go use recursion to perform the lookup. However whenever people were to load a website, the web browsers would hang and sometimes time out as bind9 had to first time out with iiNet on each request before performing recursion. Hitting F5 to refresh on the client workstation would then load the website.
If anyone knows of any highly available DNS servers in Perth that are redundant that are open to the public on all IP ranges can you please leave a comment and let us know. I believe it is better to always forward DNS requests to a local public DNS server with low latency because:
- It reduces the work for your DNS server to always perform recursion to resolve each request.
- It saves Internet usage if your Internet link supports WAIX (Western Australian Internet Exchange - free data around Perth between different ISP's) as your only talking to a local server instead of DNS servers around the world as you would be if you were using recursion.
- It speeds up DNS - A public DNS server has a much bigger cache so many requests there is a higher chance the public DNS server may already have it cached. Just ensure the public DNS server your using is protected against cache poisoning!