local DNS server

[Chong Yu Meng]

On Wed, 2006-12-06 at 12:34 +0200, Dotan Cohen wrote:
> I've heard that one could run a local DNS server to speed up internet
> access. Does this have a real-world advantage for a home user? As I
> understand it, the first time I go to www.example.com it would have to
> contact the ISP's DNS servers to find the address, so there is not
> advantage, but the next time it should be cached. Is this accurate?
> Can someone fill me in?
> 
Hi Dotan,

You are quite right about your example. The assumption is that you are
more likely to visit the same website more than once (maybe even several
times in the course of a single day or week). I think that's a
reasonable assumption. But there is another aspect to this:

Your ISP and/or your company/organization may run its own name servers,
but in some cases, these name servers may not be very reliable (or even
available). Having your own local caching DNS server gives you the
ability to continue resolving names and accessing websites even when the
upstream DNS server is down. For this reason alone, I run a caching DNS
service on my laptop. 

HTH,
pascal chong