We have just setup a recursive DNS server using the latest stable release of Bind 9.10
We are finding that recursive DNS lookups are quite slow. Anywhere from 1 - 3 seconds. Once the lookup is in cache, DNS resolves in a matter of milliseconds as expected.
We are utilising ROOT hints for the recursive lookups and this seems to be where the slowness is coming from. If we configure a forwarder the DNS resolution comes down to a sensible recursion time of 100 - 300ms.
For the service we are setting up, I don't want to rely on forwarders, I would prefer to use root hints.
Here is the main config from our named.conf file. Any pointers to help improving the performance would be great.
options{
allow-recursion { any; };
allow-query-cache { any; };
allow-query { any; };
listen-on port 53 { any; };
listen-on-v6 port 53 { any; };
dnssec-enable yes;
dnssec-validation yes;
dnssec-lookaside auto;
zone-statistics yes;
max-cache-ttl 3600;
max-ncache-ttl 3600;
/* Path to ISC DLV key */
bindkeys-file "/etc/named.iscdlv.key";
managed-keys-directory "/var/named/dynamic";
directory "/var/named";
dump-file "/var/named/data/cache_dump.db";
statistics-file "/var/named/stats/named_stats.txt";
memstatistics-file "/var/named/stats/named_mem_stats.txt";
rate-limit {
responses-per-second 10;
log-only yes;
};
prefetch 5;};
zone "." {
type hint;
file "named.ca";};
include "/var/named/conf/logging.conf";
