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Installing and confuring caching_nameserver (named) on Linux (Fedora 12)
To configure caching-nameserver on local machine in my case on my laptop running Fedora 12, local caching nameserver which will use "cascade" to other functional DNS server in this case my ISP DNS servers.
Advantage: Reduces the delay in domain name resolution drastically as the requests for frequently accessed websites are served from cache. Google for cache nameserver to learn more.
Installing caching-nameserver
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# yum install caching-nameserver
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Configuring caching-nameserver
The main configuration file reside in /etc/named.conf.
Not much need to be changed in this file, however if you want to cascade your ISP DNS servers as forwarder, then edit the named.conf and add forwarder directive under the 'options' section.
options {
listen-on port 53 { 127.0.0.1; };
listen-on-v6 port 53 { ::1; };
directory "/var/named";
dump-file "/var/named/data/cache_dump.db";
statistics-file "/var/named/data/named_stats.txt";
memstatistics-file "/var/named/data/named_mem_stats.txt";
allow-query { localhost; };
recursion yes;
// Replace the IPs with the DNS of your ISP
forwarders { 192.168.36.204; 192.168.36.210; };
dnssec-enable yes;
dnssec-validation yes;
dnssec-lookaside . trust-anchor dlv.isc.org.;
};
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And if you do not want to use DNSSEC then disable it by...
dnssec-enable no;
dnssec-validation no;
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Starting caching-nameserver
Need to define a contact for management station in the same way we create for other contact person, to receive SNMP traps from Nagios whereever Nagios send notificaiton for host/service
# service named start
OR
# /etc/init.d/named start
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To make named start every time you reboot your machine
Using caching-nameserver
To use your caching-nameserver, add the following line to /etc/resolv.conf
Now your system will use your own nameserver (in caching mode) for resolving all domain names
$ dig askarali.org
Query time: 8 msec
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First time the response time will be little high, next time the DNS query response will be served from local cache and will takes very little time
$ dig askarali.org
Query time: 0 msec
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