Bob Goodwin wrote:
*jdow wrote:*
*From: "Bob Goodwin" <bobgoodwin@xxxxxxxxxxxx>
*
**Ed Greshko wrote:*
*
**Bob Goodwin wrote:
*
*
**I've done "yum install caching-nameserver" and with a few crude
tests
it appears that it might be working.
Is there a file of cached addresses that I can look at and see that
they are actually being cached?
*
*
**
Not that I know of....
However, you can do a "host -v somehost.com" were somehost is equal
to a
host name you've not visited. The first time you do it you may see
something like:
Received 194 bytes from 127.0.0.1#53 in 1291 ms
But if you do it again, and it is working, you should see something on
the order of:
Received 194 bytes from 127.0.0.1#53 in 1 ms
*
*
**Ok, I tried:
*
*host -v speakeasy.net *
*First time:
Received 109 bytes from 127.0.0.1#53 in 745 ms
Second time:
Received 109 bytes from 127.0.0.1#53 in 105 ms
That would seem to indicate that it works?
I'm not sure it's of much value considering the round trip time to
the satellite but I guess every little bit helps. I was timing the
"Looking up google.com" or whatever at the bottom of the Thunderbird
screen and timing that. It looked faster after the initial trial ...
*
*
No - that would include cached images and all that nonsense. Use the
commandline and something like "host nlzero.com", one I bet you have
never touched before. Google you have touched before regularly and
is probably still cached.
Round trip to the satellite? Then the second one did not come via
the satellite. But the delay is incredibly long for coming from
something local. (The first one does look like a satellite hop round
trip, potentially. One hop is a touch over 1/4 second absolute minimum.
Add to that some overhead for communications reliability and the
satellite's processing time, also.)
{^_^}
*
*Yeah, the satellite introduces a bit less than 500 ms of delay for
transit
time in addition to the usual system delays. When I look at ntpq I see
typically 600-700 ms there.
I thought the 100 ms I'm seeing for the local dns looked long but I
have no
experience other than this. As it is it's till less than the 700-800
otherwise. Yes, I understand that google is frequently used and should
be in the local cache,
that was merely an example, thought I made that clear.
Bob Goodwin
*
Now another problem, I rebooted the computer and /etc/resolv.conf
is re-written without the "nameserver 127.0.0.1" line and whatever
cache was collected is gone, so the local stuff has to be collected again.
That and now you've got me worried about the time, I'm still seeing
130-150 ms,
much shorter than using the Wildblue dns server but perhaps it should be
better?
Before and after for "host -v google.com"
Received 252 bytes from 127.0.0.1#53 in 917 ms
Received 252 bytes from 127.0.0.1#53 in 151 ms
Bob Goodwin
