We have 5 servers currently using the one domain name for their dns

server 1 has the domain name and the ns entries for all the servers...

ie:

domain.com
server1.domain.com
ns1.domain.com
ns2.domain.com
server2.domain.com
ns3.domain.com
ns4.domain.com
server3.domain.com
ns5.domain.com
ns6.domain.com
server4.domain.com
ns7.domain.com
ns8.domain.com
server5.domain.com
ns9.domain.com
ns10.domain.com
server6.domain.com
ns11.domain.com
ns12.domain.com

ns1.domain.com and ns2.domain.com use IP's from the server1 server
ns3.domain.com and ns4.domain.com use IP's from the server2 server
ns5.domain.com and ns6.domain.com use IP's from the server3 server
ns7.domain.com and ns8.domain.com use IP's from the server4 server
ns9.domain.com and ns10.domain.com use IP's from the server5 server
ns11.domain.com and ns12.domain.com use IP's from the server6 server


now if server 1 falls over the nameservers for the rest of the servers goes down (assuming a long outage)

I need to have it so that if server 1 goes down the other servers are unaffected.

Now i figured to get around this the easiest way was to put the even numbered ns on IP's on one server and the odd ones on another.

I would also want to make sure that resellers second nameservers were on a different server so they have redundancy as well

Ive tried setting up nameserversthe servers in a cluset in whm but this was a complete disaster as some sites had old dns on other servers and none of them seemed to want to sync properly

To complicate matters worse.. 3 servers are in Australian and 3 in the US and i would like it so that if (in the unlikely event) the australia to us connections go down or are ordinary locals will pick up the dns from one of the australian servers....

am i on the right track or have i missed the point completely???

can anyone offer some advice on the best way to set things up, especially in such a way to add in extra servers as theres actually some 30 servers to link up

Are you sure you want to make a cluster of 30 cPanel servers??!!??!! While the cPanel dns cluster is decent (the built in program) it is going to cause a lot of problems if you try to get it anywhere near 30 servers.

As far as redundancy I am not sure how about Australia is but in the UK it can take days for people to get a new IP from DNS servers because of caching. I would really suggest that you think twice about doing so many servers.

If you are doing separate clusters the important thing is to simply have ns1 and ns2 on different servers. If you want geo-redundancy then each one should be on a different continent. I would also recommend keeping the TTL's low to help speed up the switch over if it should be needed.

Agreed. Keep your TTL's low so the values refresh/update faster in the event of a switch. Unless someone pulls the plug on the entire Internet you should be fine with 2 main NS servers that are in separate datacenters/locations.