caching-namserver

[Bob Goodwin]

*Tim wrote:*
> *would have said it's a fair bet.  But doing queries on the localhost
> shouldn't involve the rest of the network.
>
> It looks like you might have a similar issue to what I had (that one of
> the PCs is slower to use its own DNS server than another was).  You
> could try running the caching nameserver on several boxes, comparing the
> results.  Today, the fastest internal response I can get is 33 mS doing
> a lookup up on localhost.localdomain at the DNS server localhost
> address.  i.e. dig localhost.localdomain @ 127.0.0.1  It varies between
> 33 and 60+ mS to return results.
> *
> *If you were doing queries across the wireless link to another box, I
> *
*
I have observed instances where the initial response time was near 1000 ms,
the second in the tens of ms and then subsequent checks would be above 
100 ms?

Initially for host -a google.com:
Received 220 bytes from 127.0.0.1#53 in 1047 ms

Then a few seconds later:
Received 220 bytes from 127.0.0.1#53 in 38 ms

Now some hours later:
Received 156 bytes from 127.0.0.1#53 in 467 ms

Then using dig <dig google.com>
;; Query time: 168 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Wed Aug 23 13:15:23 2006
;; MSG SIZE  rcvd: 148

Repeated several times, always 164-168 ms.

Then here's one I have not visited today, an address Joanne provided the 
other day.

dig nlzero.com

; <<>> DiG 9.3.2 <<>> nlzero.com
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 3375
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 0

;; QUESTION SECTION:
;nlzero.com.                    IN      A

;; ANSWER SECTION:
nlzero.com.             38400   IN      A       209.166.88.53

;; AUTHORITY SECTION:
nlzero.com.             38400   IN      NS      ns1.domainvanhorn.com.
nlzero.com.             38400   IN      NS      ns2.domainvanhorn.com.

;; Query time: 3180 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Wed Aug 23 13:21:48 2006
;; MSG SIZE  rcvd: 94


dig nlzero.com

; <<>> DiG 9.3.2 <<>> nlzero.com
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 48766
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 0

;; QUESTION SECTION:
;nlzero.com.                    IN      A

;; ANSWER SECTION:
nlzero.com.             38383   IN      A       209.166.88.53

;; AUTHORITY SECTION:
nlzero.com.             38383   IN      NS      ns2.domainvanhorn.com.
nlzero.com.             38383   IN      NS      ns1.domainvanhorn.com.

;; Query time: 244 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Wed Aug 23 13:22:05 2006
;; MSG SIZE  rcvd: 94

Then the same address using <host -a nlzero.com>

Received 122 bytes from 127.0.0.1#53 in 382 ms

The correlation between the two methods is not perfect?

I need to try the same things with another FC5 computer. But that requires
sometime to update again and install the caching-nameserver on it.

I did try pinging google with the Dell XP box yesterday.
The average of three pings was 775 ms but I don't know how to check the dns
response time with Windows?  I did try pinging itself and all it gave me 
was
less than 1ms to 127.0.0.1.  Unlike FC5, it does not read out in the 
µsec range.

BobG*