nscd and DNS cache

[JD]

On 05/18/2012 01:21 AM, Ed Greshko wrote:
> On 05/18/2012 03:47 PM, JD wrote:
>> I am indeed pointing my resolv.conf to the 2 google
>> nameservers.
>> You're probably right about our home network.
>> I think the router has a very low bandwidth (hardware wise),
>> probably because it doubles up as the decoder for the TV
>> contents being viewed on 2 to 3 different TV's in the  house.
>> TV signals come directly to the router on the coax, and then
>> are sent back on the coax to the 3 TV sets.
>> We're stuck with what we have.
> Of course you can always use a tool such as dig to see what kind of response times
> you are getting.
>
> for example....
>
> [egreshko at meimei ~]$ dig @8.8.8.8 www.ibm.com
>
> ;<<>>  DiG 9.8.2-RedHat-9.8.2-1.fc16<<>>  @8.8.8.8 www.ibm.com
> ; (1 server found)
> ;; global options: +cmd
> ;; Got answer:
> ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 13263
> ;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0
>
> ;; QUESTION SECTION:
> ;www.ibm.com.                   IN      A
>
> ;; ANSWER SECTION:
> www.ibm.com.            452     IN      CNAME   www.ibm.com.cs186.net.
> www.ibm.com.cs186.net.  34      IN      A       129.42.60.216
>
> ;; Query time: 21 msec
> ;; SERVER: 8.8.8.8#53(8.8.8.8)
> ;; WHEN: Fri May 18 16:17:54 2012
> ;; MSG SIZE  rcvd: 80
>
> Shows the query took 21 milliseconds
>
That value is good for comparison only as it is not
the real time. Take a look at this:

time dig @8.8.8.8 www.ny.com

; <<>> DiG 9.8.2-RedHat-9.8.2-1.fc16 <<>> @8.8.8.8 www.ny.com
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 24466
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;www.ny.com.            IN    A

;; ANSWER SECTION:
www.ny.com.        3383    IN    CNAME    web1.ny.com.
web1.ny.com.        3383    IN    A    184.106.212.108

;; Query time: 61 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Fri May 18 03:17:11 2012
;; MSG SIZE  rcvd: 63


real    0m10.07s
user    0m0.01s
sys    0m0.01s

So, the router or my super lightly loaded laptop,
or the ISP, must be the cause of such delays.

$  w
  03:20:45 up  5:52,  3 users,  load average: 0.02, 0.02, 0.05