Multiple DNS

Andrew Pantyukhin infofarmer at
Sun Feb 19 10:40:44 PST 2006

On 2/19/06, Robert Slade <bsd at> wrote:
> Hi,
> I am looking for some advice. I have a network which is based on a
> number of servers running FreeBsd 6.0 serving Win XP work stations. (yes
> I know but..) The network is large enough to use DHCP and DNS for the
> internal network, I have setup a DHCP server with a Dynamic DNS (Bind 9)
> on one of the servers. That server is handling the LDAP side of the
> domain.
> There appears to be a fair bit of DNS Traffic which leads to a secondary
> DNS being required to take some of the load as DNS lookup are slow. The
> question I have is should I just setup a cashing DNS on another server
> using the primary as a forwarder or even several servers eg the mail
> server and the secondary LDAP server, or should I setup a proper
> secondary DNS using my ISP as a forwarder with dynamic updates from the
> primary.
> Sorry if this is a bit vague, but I have no experience in this area.
> Rob
> _______________________________________________
> freebsd-questions at mailing list
> To unsubscribe, send any mail to "freebsd-questions-unsubscribe at"

A secondary server using the primary as a forwarder is
generally a better idea if the primary is stable enough.
The secondary will share some load without taking up
extra bandwidth.

In case the primary is not stable enough, or if you really
need to scale by 2 (i.e. share the load evenly between
the servers), you'll have to use the ISP's dns servers as
forwarders instead. This will cut the efficiency of your
DNS cache by two.

At our place (3000+ hosts) we have our primary on a
rock-solid box and secondaries using it as forwarder.

More information about the freebsd-questions mailing list