Cpanel DNS Cluster Configuration - how it should be configured
If at all possible, you should link your web server directly to the DNS servers, you will need to sync each web server to its DNS servers.
Performance:
Creating a cluster setup with direct links between servers can decrease CPU load, improving the performance of your servers. The more steps, or “hops,” between a web server and a nameserver, the slower the servers’ performance will be.
You should not set a DNS server to sync data back to a web server, as this will put extraneous data on the web server.
For each intermediate server you add, the data transfer time is 3 times slower than for a direct link.
Enabling DNS clustering on cpanel server
First, you will need to enable DNS clustering via each server’s WHM interface.
You will need to sync each web server to its DNS servers.
You do not need to link dedicated DNS servers to each other, or link dedicated web servers to each other.
You should not set a DNS server to sync data back to a web server, as this will put extraneous data on the web server.
Steps:
1. Navigate to WHM’s Configure Cluster screen.
2. Click Enable Dns Clustering.
3. Click Change.
4. Click Return to Cluster Status.
DNS clustering is now enabled. Next, you will need to specify which server(s) you wish to cluster, or share DNS information with.
Advanced tool to enable/disable recursive DNS lookups
DNS recursion support is defined under BIND 9, using the `recursion’ and the `allow-recursion’ directives, as part of the options grammar.
Download
http://download.swsoft.com/ensim/download/pro/linux/kb/2344/recursivedns
Installation Instructions
Download the script and copy in “/usr/lib/opcenter/bind/” directory.
recursivedns : ‘recursivedns’, allows you to modify the DNS recursion settings for your EPL server.
Invoking the script
To display the recursion settings, just run `recursivedns‘
To turn on recursion support, run `recursivedns on‘
To turn off recursion support, run `recursivedns off‘
To allow recursion to all hosts, run `recursivedns +all‘
To disallow recursion to all hosts, run `recursivedns -all‘
To allow recursion to a particular host, run `recursivedns +HOST‘
To disallow recursion to a particular host, run `recursivedns -HOST‘
To display the usage, run `recursivedns –help‘
Using Perl to make changes to your DNS files
Example : You would like to change “v=spf1 a mx ip4:1.2.3.4 ?all” to “v=spf1 a mx ip4:1.2.3.4 -all”
of course, where 1.2.3.4 should be replaced by your server IP.
If you’d rather do this to all of your domain, you can use perl
cd /var/named
perl -pi -e ’s/\?all/\-all/’ *.db
change /var/named to the appropriate directory for your db files for your OS (/etc/bind, /etc/namdb)
Restart named after making the changes.
Setup Primary and Secondary (Slave) DNS server in Plesk.
Setup should allow zone transfer for the secondary DNS server in Plesk.
To allow it, secondary DNS server’s IP should be listed in NS records for all zones on Plesk server or it should be added to Access Control List (ACL).
ACL is be managed on the Server->DNS Settings->Common ACL page in Plesk CP.
In case if you wish to use non Plesk server as slave DNS, all DNS zones have to be created on the secondary DNS server in /etc/named.conf (this file location may be differ depending on OS) with ’slave’ type, for example:
zone “serverbuddies.com” {
type slave;
file “serverbuddies.com.zone”;
masters { 192.168.0.1; };
};
Restart named after that. Now slave DNS server will get zones information from Plesk (master DNS server).
Source: http://parallels.net/Plesk/
