Gareth, Paul, et al,
> dig is the seminal tool for testing all things DNS related. It's simple
> to use, but very powerful.
Just an off-topic footnote: As per Gareth's post, dig is a recommended
tool to check up on the "caching" mechanisms in bind, the DNS timings,
etc. The first access to an external site may take 20-100-500-750
millisecs. If the caching is working well, subsequent accesses should be
under 1 millisec.
BUT - my guess is that dig is observing the timings, WHILE it is
displaying the output data, rather than running all the timings first,
and THEN displaying all the results. However, I've not checked the
source code.
So:
- if you're running dig in any standard "console", and
- the output from dig is scrolling on the screen, and
- you're interested in the lookup timings, and
- the DNS lookups are cached (and take only some microsecs), then
practically ALL the timings will relate to the scrolling speed of the
console handlers rather than the DNS lookup speeds!!
So... I suggest something like: clear; dig xxxxxx
Also, AFAIK, if you're using the /etc/hosts file to filter out the crap
sites, dig does not honour its contents.
- Mike
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