We currently have several servers running in 3 different datacentres all using the same domain name for their nameservers....

ie:

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

etc etc

Now the dns entries for all these sservers is on server1.domain.com.

The problem we have is that if server 1 goes down for any length of time the dns for the rest of the servers goes down as well.

Can someone explain what the best way would be to set them all up so that theres redundancy.

whatever we need to do cant affect the uptime of customers on these servers however...

Can someone do a How to for dummies on this...

TIA

Cpanel has a DNS clustering feature I'm aware off.

if its cpanel, the easiest way, as rabit said, is the dns clustering in cpanel.

if only 2 of the three have cpanel, you can download the free DNSONLY cpanel


HOWEVER, if its not cpanel, and its *nix

http://www.djbdnsrocks.org its a secure, fast, brilliant DNS server.

Thanks for the tips

I thought if you registered these with the registrar that they would have all of the NS IP's regardless of whether the main domain is up or not?

I think Snowman meant that ns1.domain.com through ns6.domain.com were actually all on server1.domain.com (the other servers are just referencing server1). If server1 dies, all zones on all his servers die as well :shock:

Yes thats exactly what i meant....

im just not sure how to fix it without causing downtime or problems for clients on all the servers...

any suggestions???

i know this is from a while back but i will ask again...

anyone have any suggestions on what the best way to do this would be?

obviously having ns1 and ns2 on 2 different servers would do the trick i would assume but whats the bst way of doing this?

What about setting up secondary DNS on your other two servers or with ServerMatrix?

Your primary DNS server contains the zone files which define IP addresses and hostnames for a zone (domain). A secondary DNS (a.k.a slave DNS) server contains the same information, but it obtains its information from the primary DNS server. If your primary server is down the cached copy of the zone on the secondary DNS will provide authoritive results until the primary server is back up.

If you open a DNS ticket with SM they will configure a secondary DNS for you.

Do you have a Windows or Linux server?

Ross

we have both

currently we have ns1 and ns2 and all sub servers running of the one nix server which obviously isnt a good thing

If you have a windows server you can setup secondary dns like this:

Install the DNS service (add/remove windows components)
Open DNS manager
Right-click forward lookup zones
New zone
Choose Secondary zone
enter the domain name
Enter the ip address of your primary dns server
Finish

On your primary server you will need to allow zone transfers to your secondary server in the properties for the zone.

After this is setup you need to add the secondary server as a nameserver for the domain.

Otherwise getting SM to provide a backup is a simple option.

Ross

no we run Linux

We have 6 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.

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???

All of that stuff is hard to understand unless you use the real domain and ip addresses.

You need to setup some secondary dns entries (called SLAVE entries in linux).

Install a DNS server on one of your other servers and add a slave entry for your domain. Then list that server as ns2 for the domain.

Another thing I would do is open a ticket with servermatrix and get them to also add a slave dns entry.

A good tool to use to check things are ok is : http://www.dnsreport.com

Ross

Does Windows DNS have a way to put in a key to use for the zone transfer so it can't be spoofed into accepting incorrect zone updates ?

-- David

Umm.. you are confused. A zone transfer is just allowing a full copy of the dns zone to be sent to another server. It does not update my zone. This is used by the slave dns server to keep a copy of my primary zone. The slave server will only update from a specific ip address so it cant be "tricked".

Windows DNS can allow zone transfers to anyone or or just to certain ip addresses (usually your slave/secondary dns servers).

Ross