Re: [PLUG] DNS question (config reality check)

[Stephen Gran <steve@lobefin.net>]

On Mon, Jun 07, 2004 at 10:29:05AM -0400, Jeff Abrahamson said:
> My internal DNS mysteriously stopped working this morning.  It only
> affected unqualified local machine names.
> 
> I got things mostly working by adding a couple lines to /etc/hosts.
> But I'd like to figure out what went wrong and what I should really do
> about it.
> 
> My /etc/resolv.conf file says this:

[snip]

> On 192.168.0.5, where most of this should happen, /etc/resolv.conf
> says

[snip]

Both snipped because they look fine.

> Then I have db.purple:

[snip]

Which looks fine except for the localhost entry - that might confuse
things, since bind also by default has a db.127 with this information.
It shouldn't really hurt, though.

> Here's the signature of the problem (one failed dig, one successful).
> Seems that it's querying the wrong name server when I don't qualify.
>     jeff@asterix:jeff $ dig diderot
[nothing]
>     jeff@asterix:jeff $ dig diderot.purple.com
[normal]

Does 'host' work as expected?  I am not sure of the differences in
implementation, but I see similar thing here - dig doesn't return
anything on unqualified names for my internal DNS, but host does.  I get
the impression dig doesn't read resolv.conf for anything but
nameservers.  There is the command line switch +domain used ike so:
dig gashuffer +domain=lobefin.net 
which does work as expected.

Here is what I see:
steve:~$ dig gashuffer

; <<>> DiG 9.2.4rc2 <<>> gashuffer
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 12970
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0

;; QUESTION SECTION:
;gashuffer.                     IN      A

;; AUTHORITY SECTION:
.                       2221    IN      SOA     A.ROOT-SERVERS.NET. NSTLD.VERISIGN-GRS.COM. 2004060601 1800 900 604800 86400

;; Query time: 2 msec
;; SERVER: 192.168.0.1#53(192.168.0.1)
;; WHEN: Mon Jun  7 10:53:21 2004
;; MSG SIZE  rcvd: 102

steve:~$ dig gashuffer.lobefin.net

; <<>> DiG 9.2.4rc2 <<>> gashuffer.lobefin.net
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 11437
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 2

;; QUESTION SECTION:
;gashuffer.lobefin.net.         IN      A

;; ANSWER SECTION:
gashuffer.lobefin.net.  604800  IN      A       192.168.0.5

;; AUTHORITY SECTION:
lobefin.net.            604800  IN      NS      mail.lobefin.net.
lobefin.net.            604800  IN      NS      hadrian.lobefin.net.

;; ADDITIONAL SECTION:
mail.lobefin.net.       604800  IN      A       216.158.52.98
hadrian.lobefin.net.    604800  IN      A       192.168.0.1

;; Query time: 2 msec
;; SERVER: 192.168.0.1#53(192.168.0.1)
;; WHEN: Mon Jun  7 10:53:24 2004
;; MSG SIZE  rcvd: 128

steve:~$ host gashuffer
gashuffer.lobefin.net   A       192.168.0.5

But things work as expected:

steve:~$ ping gashuffer
PING gashuffer.lobefin.net (192.168.0.5): 56 data bytes
64 bytes from 192.168.0.5: icmp_seq=0 ttl=64 time=0.2 ms
64 bytes from 192.168.0.5: icmp_seq=1 ttl=64 time=0.1 ms

--- gashuffer.lobefin.net ping statistics ---
2 packets transmitted, 2 packets received, 0% packet loss
round-trip min/avg/max = 0.1/0.1/0.2 ms
steve:~$

With:
search lobefin.net
domain lobefin.net
nameserver 192.168.0.1

in resolv.conf

HTH,
-- 
 --------------------------------------------------------------------------
|  Stephen Gran                  | Fame is a vapor; popularity an          |
|  steve@lobefin.net             | accident; the only earthly certainty is |
|  http://www.lobefin.net/~steve | oblivion.   -- Mark Twain               |
 --------------------------------------------------------------------------

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