[dns-operations] Why would a recusrive caching server not resolve a CNAME?

[Lyle Giese]

You waited less than an hour before proclaiming the list defunct? It's 
Sunday in most of the world.  Most of us are doing other things than 
sitting on this list.

That said, my initial thought is that your server answered your 
question.  Nothing more.  Did you ask it for the A record for 
googlemail.l.google.com ?  That might have told you more.

Lyle Giese
LCR Computer Services, Inc.

On 07/06/14 13:38, Mohamed Lrhazi wrote:
> I am thinking this list is not appropriate for some of my questions... 
> Could someone suggest a better one, maybe as active and rich, as this 
> one, but more appropriate for general DNS discussions?
>
> Thanks a lot,
> Mohamed.
>
>
> On Sun, Jul 6, 2014 at 2:02 PM, Mohamed Lrhazi <ml623 at georgetown.edu 
> <mailto:ml623 at georgetown.edu>> wrote:
>
>     We had a little mail outage which turned out to be caused by one
>     of our caching DNS servers returning the bellow incomplete reply.
>
>     Clearing the cache on the problematic server fixed the issue....
>
>     Am thinking it is now impossible for me to find the root cause in
>     this instance... but wondering if you guys could hint at what
>     could cause such a problem... bugs in the DNS servers involved?
>     temporary misconfig at Google's servers? network issue?
>
>     The setup is a bit convoluted:
>
>     cache server --> resolver cache server --> Internet
>
>     The fix was clearing at the first server. so I am guessing at some
>     point the resolver gave the incomplete answer.
>
>     Thanks a lot,
>     Mohamed.
>
>     ?  ~  dig mail.google.com <http://mail.google.com>
>     @141.161.100.201 <http://141.161.100.201>
>
>     ; <<>> DiG 9.9.5-3-Ubuntu <<>> mail.google.com
>     <http://mail.google.com> @141.161.100.201 <http://141.161.100.201>
>     ;; global options: +cmd
>     ;; Got answer:
>     ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 20414
>     ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 4, ADDITIONAL: 5
>
>     ;; OPT PSEUDOSECTION:
>     ; EDNS: version: 0, flags:; udp: 4096
>     ;; QUESTION SECTION:
>     ;mail.google.com <http://mail.google.com>.INA
>
>     ;; ANSWER SECTION:
>     mail.google.com
>     <http://mail.google.com>.10213INCNAMEgooglemail.l.google.com
>     <http://googlemail.l.google.com>.
>
>     ;; AUTHORITY SECTION:
>     google.com <http://google.com>.96485INNSns2.google.com
>     <http://ns2.google.com>.
>     google.com <http://google.com>.96485INNSns3.google.com
>     <http://ns3.google.com>.
>     google.com <http://google.com>.96485INNSns4.google.com
>     <http://ns4.google.com>.
>     google.com <http://google.com>.96485INNSns1.google.com
>     <http://ns1.google.com>.
>
>     ;; ADDITIONAL SECTION:
>     ns3.google.com <http://ns3.google.com>.108462INA216.239.36.10
>     <tel:216.239.36.10>
>     ns4.google.com <http://ns4.google.com>.108462INA216.239.38.10
>     <tel:216.239.38.10>
>     ns1.google.com <http://ns1.google.com>.108462INA216.239.32.10
>     <tel:216.239.32.10>
>     ns2.google.com <http://ns2.google.com>.108462INA216.239.34.10
>     <tel:216.239.34.10>
>
>     ;; Query time: 22 msec
>     ;; SERVER: 141.161.100.201#53(141.161.100.201)
>     ;; WHEN: Sun Jul 06 12:42:09 EDT 2014
>     ;; MSG SIZE  rcvd: 207
>
>
>
>
>
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