+trace does not do what you think it does. It does not query the target name 
server for each successive query. Rather, it causes the 'dig' command to 
perform recursion on its own, only using the indicated server (@server) to seed 
its root server list. +trace also stops at the CNAME, and does not restart the 
recursion process as needed to track down the final A record(s).

Perform the trace manually, using either +dnssec or at least +bufsize=4096. For 
example, one step in the process will look like this:

dig +bufsize=4096 +norec www.yahoo.com @ns1.yahoo.com

You will find that the Yahoo load balancers do not understand EDNS0. This might 
be part of the problem, although named should be able to work around this 
automatically. Check the log file (or configure logging as needed and re-run 
the query against your problem server) to see if it will tell you exactly what 
the problem is.

Chris Buxton
BlueCat Networks

On Feb 3, 2011, at 6:07 PM, Tory M Blue wrote:

> On Thu, Feb 3, 2011 at 5:23 PM, Barry Margolin <bar...@alum.mit.edu> wrote:
>> In article <mailman.1636.1296781581.555.bind-
>> SNIPPED<
>> www.yahoo.com.    300   IN CNAME fp.wg1.b.yahoo.com.
>> 
>> And even when they did, it didn't get involved until you followed the
>> CNAME returned for www.yahoo.com.  Your log message above indicates an
>> issue just with the yahoo.com domain, not resolution of the CNAME target.
>> 
>> --
> Thanks Barry so maybe I need some further education
> 
> 
> [tblue@mx3 ~]$ dig @problemserver.net  www.yahoo.com
> 
> ; <<>> DiG 9.6.2-P2-RedHat-9.6.2-5.P2.fc12 <<>> @problemserver.net 
> www.yahoo.com
> ; (1 server found)
> ;; global options: +cmd
> ;; connection timed out; no servers could be reached
> 
> So let's add the trace option (Same servers)
> 
> [tblue@mx3 ~]$ dig @problemserver.net  www.yahoo.com  +trace
> 
> ; <<>> DiG 9.6.2-P2-RedHat-9.6.2-5.P2.fc12 <<>> @problemserver.net
> www.yahoo.com +trace
> ; (1 server found)
> ;; global options: +cmd
> .                     514246  IN      NS      f.root-servers.net.
> .                     514246  IN      NS      b.root-servers.net.
> .                     514246  IN      NS      e.root-servers.net.
> .                     514246  IN      NS      a.root-servers.net.
> .                     514246  IN      NS      l.root-servers.net.
> .                     514246  IN      NS      k.root-servers.net.
> .                     514246  IN      NS      i.root-servers.net.
> .                     514246  IN      NS      d.root-servers.net.
> .                     514246  IN      NS      c.root-servers.net.
> .                     514246  IN      NS      m.root-servers.net.
> .                     514246  IN      NS      j.root-servers.net.
> .                     514246  IN      NS      h.root-servers.net.
> .                     514246  IN      NS      g.root-servers.net.
> ;; Received 336 bytes from 10.13.255.101#53(10.13.255.101) in 1 ms
> 
> com.                  172800  IN      NS      a.gtld-servers.net.
> com.                  172800  IN      NS      b.gtld-servers.net.
> com.                  172800  IN      NS      c.gtld-servers.net.
> com.                  172800  IN      NS      d.gtld-servers.net.
> com.                  172800  IN      NS      e.gtld-servers.net.
> com.                  172800  IN      NS      f.gtld-servers.net.
> com.                  172800  IN      NS      g.gtld-servers.net.
> com.                  172800  IN      NS      h.gtld-servers.net.
> com.                  172800  IN      NS      i.gtld-servers.net.
> com.                  172800  IN      NS      j.gtld-servers.net.
> com.                  172800  IN      NS      k.gtld-servers.net.
> com.                  172800  IN      NS      l.gtld-servers.net.
> com.                  172800  IN      NS      m.gtld-servers.net.
> ;; Received 494 bytes from 199.7.83.42#53(l.root-servers.net) in 11 ms
> 
> yahoo.com.            172800  IN      NS      ns1.yahoo.com.
> yahoo.com.            172800  IN      NS      ns5.yahoo.com.
> yahoo.com.            172800  IN      NS      ns2.yahoo.com.
> yahoo.com.            172800  IN      NS      ns3.yahoo.com.
> yahoo.com.            172800  IN      NS      ns4.yahoo.com.
> ;; Received 201 bytes from 192.31.80.30#53(d.gtld-servers.net) in 55 ms
> 
> www.yahoo.com.                300     IN      CNAME   fp.wg1.b.yahoo.com.
> wg1.b.yahoo.com.      300     IN      NS      yf2.yahoo.com.
> wg1.b.yahoo.com.      300     IN      NS      yf4.yahoo.com.
> wg1.b.yahoo.com.      300     IN      NS      yf8.yahoo.com.
> wg1.b.yahoo.com.      300     IN      NS      yf3.yahoo.com.
> wg1.b.yahoo.com.      300     IN      NS      yf6.yahoo.com.
> wg1.b.yahoo.com.      300     IN      NS      yf5.yahoo.com.
> wg1.b.yahoo.com.      300     IN      NS      yf1.yahoo.com.
> wg1.b.yahoo.com.      300     IN      NS      yf7.yahoo.com.
> ;; Received 326 bytes from 68.180.131.16#53(ns1.yahoo.com) in 2 ms
> 
> 
> So what am I missing? No servers available and the trace shows that
> it's finding the CNAME record, but doesn't appear to be going far
> enough,
> 
> 
> Here is the second server who can resolve this. Identical
> configuration as the problem server, same network segment, behind same
> SNAT, the same..
> 
> [tblue@mx3 ~]$ dig @functioningserver.net  www.yahoo.com
> 
> ; <<>> DiG 9.6.2-P2-RedHat-9.6.2-5.P2.fc12 <<>> @functioningserver.net
> www.yahoo.com
> ; (1 server found)
> ;; global options: +cmd
> ;; Got answer:
> ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 30158
> ;; flags: qr rd ra; QUERY: 1, ANSWER: 4, AUTHORITY: 2, ADDITIONAL: 0
> 
> ;; QUESTION SECTION:
> ;www.yahoo.com.                       IN      A
> 
> ;; ANSWER SECTION:
> www.yahoo.com.                300     IN      CNAME   fp.wg1.b.yahoo.com.
> fp.wg1.b.yahoo.com.   3238    IN      CNAME   any-fp.wa1.b.yahoo.com.
> any-fp.wa1.b.yahoo.com.       60      IN      A       98.137.149.56
> any-fp.wa1.b.yahoo.com.       60      IN      A       72.30.2.43
> 
> ;; AUTHORITY SECTION:
> wa1.b.yahoo.com.      300     IN      NS      yf2.yahoo.com.
> wa1.b.yahoo.com.      300     IN      NS      yf1.yahoo.com.
> 
> ;; Query time: 1759 msec
> ;; SERVER: 10.13.255.102#53(10.13.255.102)
> ;; WHEN: Thu Feb  3 18:03:55 2011
> ;; MSG SIZE  rcvd: 147
> 
> I'm missing something I'm sure, but it's under my skin now!
> 
> Thanks again
> Tory
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> bind-users@lists.isc.org
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