Maintained by: NLnet Labs

[Unbound-users] austereo.castmetrix.net

Haw Loeung
Tue Feb 17 14:02:00 CET 2009


Quoting Leen Besselink <leen at consolejunkie.net>:
> On Tue, Feb 17, 2009 at 01:20:59AM -0500, Paul Wouters wrote:
> > On Mon, 16 Feb 2009, krishna e bera wrote:
> > 
> > > > Anyone able to lookup austereo.castmetrix.net?
> > > > 
> > > > I tried using the resolvers running Unbound but keep getting
> NXDOMAIN. 
> > > > resolvers running BIND however returns the following:
> > 
> > I got ServFail.
> > 
> > it first gets the CNAME:
> > 
> > austereo.castmetrix.net is an alias for austereo.castmetrixcdn.net.
> > 
> > 
> > Seems there is only 1 NS for castmetrixcdn.net, which is
> > ns1.castmetrixcdn.com. There is only one NS for castmetrixcdn.com,
> > which is ns1.castmetrixcdn.com.. So glue is needed from .com.
> > 
> > ..com lists 2 NS records (ns1.castmetrixcdn.com. and
> ns2.castmetrixcdn.com,
> > both resolving to 76.74.248.77, which is the recursive nameserver.
> unbound
> > drops the second NS because the glue is bad, the child zone gives
> NXDOMAIN.
> >

Thanks Paul, I didn't notice the castmetrixcdn.COM part.


> > unbound does get there:
> > 
> > [1234850471] libunbound[14359:0] info: response for
> <ns2.castmetrixcdn.com. A IN>
> > [1234850471] libunbound[14359:0] info: reply from <castmetrixcdn.com.>
> 76.74.248.77#53
> > [1234850471] libunbound[14359:0] info: query response was ANSWER
> > 
> > But if you try to get an answer from there:
> > 
> > dig -t ns  +norecurse austereo.castmetrix.net @76.74.248.77
> >

That's right, there's no NS records for austereo.castmetrix.net from what I gather.
 

> > ;; QUESTION SECTION:
> > ;austereo.castmetrix.net.	IN	NS
> > 
> > ;; AUTHORITY SECTION:
> > castmetrix.net.		3600	IN	SOA	castmetrix.net.
> ns1.castmetrix.com.castmetrix.net. 2008031101 86400 3600 86400 3600
> > 
> > It does not know the answer. I am not sure where bind picked up the
> > answer (mine does the same, it did find it)
> > 
> 
> PowerDNS-recursor (3.1.8pre with EDNS-ping) also works (with a second
> try after clearing the cache, but see below).
> 
> I don't have a bind setup here to test, the Unbound (1.2.0) I have
> running did give the right results.
> 
> Although I have found running: dig +trace austereo.castmetrix.net.
> several times gives
> different results (and dig is from ISC, so possible works like bind was
> intended or
> something).
> 
> I had a look at a few pcap dumps I make, but I didn't see right away
> what the problem
> was. I assume the .net-TLD-nameservers might be running different
> versions/implementations
> and deal differently with the intended NS-/glue-records for the domain
> ?
> 
> ;; Received 501 bytes from 2001:7fd::1#53(k.root-servers.net) in 22 ms
> 
> castmetrixcdn.net.      172800  IN      NS      ns1.castmetrixcdn.com.
> castmetrixcdn.net.      172800  IN      NS      ns2.castmetrixcdn.com.
> ;; Received 129 bytes from 192.54.112.30#53(h.gtld-servers.net) in 20
> ms
> 
> dig: couldn't get address for 'ns2.castmetrixcdn.com': not found
> __
> 
> ;; Received 497 bytes from 192.36.148.17#53(i.root-servers.net) in 30
> ms
> 
> castmetrixcdn.net.      172800  IN      NS      ns1.castmetrixcdn.com.
> castmetrixcdn.net.      172800  IN      NS      ns2.castmetrixcdn.com.
> ;; Received 129 bytes from 192.12.94.30#53(E.GTLD-SERVERS.net) in 142
> ms
> 
> austereo.castmetrixcdn.net. 3600 IN     A       66.186.45.186
> austereo.castmetrixcdn.net. 3600 IN     A       209.11.241.178
> austereo.castmetrixcdn.net. 3600 IN     A       66.186.49.74
> austereo.castmetrixcdn.net. 3600 IN     A       209.11.243.122
> castmetrixcdn.net.      3600    IN      NS      ns1.castmetrixcdn.com.
> ;; Received 197 bytes from 76.74.248.77#53(ns1.castmetrixcdn.com) in 158
> ms
> 
> ;; Received 129 bytes from 192.31.80.30#53(D.GTLD-SERVERS.net) in 117
> ms
> 
> austereo.castmetrixcdn.net. 3600 IN     A       209.11.241.178
> austereo.castmetrixcdn.net. 3600 IN     A       66.186.49.74
> austereo.castmetrixcdn.net. 3600 IN     A       209.11.243.122
> austereo.castmetrixcdn.net. 3600 IN     A       66.186.45.186
> castmetrixcdn.net.      3600    IN      NS      ns1.castmetrixcdn.com.
> ;; Received 197 bytes from 76.74.248.77#53(ns1.castmetrixcdn.com) in 158
> ms
> 
> __
> 
> ;; Received 501 bytes from 2001:500:1::803f:235#53(h.root-servers.net)
> in 238 ms
> 
> castmetrixcdn.net.      172800  IN      NS      ns1.castmetrixcdn.com.
> castmetrixcdn.net.      172800  IN      NS      ns2.castmetrixcdn.com.
> ;; Received 129 bytes from 2001:503:231d::2:30#53(b.gtld-servers.net) in
> 118 ms
> 
> austereo.castmetrixcdn.net. 3600 IN     A       66.186.45.186
> austereo.castmetrixcdn.net. 3600 IN     A       209.11.241.178
> austereo.castmetrixcdn.net. 3600 IN     A       66.186.49.74
> austereo.castmetrixcdn.net. 3600 IN     A       209.11.243.122
> castmetrixcdn.net.      3600    IN      NS      ns1.castmetrixcdn.com.
> ;; Received 197 bytes from 76.74.248.77#53(ns1.castmetrixcdn.com) in 157
> ms
> 
> __
> 
> ;; Received 501 bytes from 2001:dc3::35#53(m.root-servers.net) in 172
> ms
> 
> castmetrixcdn.net.      172800  IN      NS      ns1.castmetrixcdn.com.
> castmetrixcdn.net.      172800  IN      NS      ns2.castmetrixcdn.com.
> ;; Received 129 bytes from 2001:503:a83e::2:30#53(A.GTLD-SERVERS.net) in
> 302 ms
> 
> austereo.castmetrixcdn.net. 3600 IN     A       209.11.243.122
> austereo.castmetrixcdn.net. 3600 IN     A       66.186.45.186
> austereo.castmetrixcdn.net. 3600 IN     A       209.11.241.178
> austereo.castmetrixcdn.net. 3600 IN     A       66.186.49.74
> castmetrixcdn.net.      3600    IN      NS      ns1.castmetrixcdn.com.
> ;; Received 197 bytes from 76.74.248.77#53(ns1.castmetrixcdn.com) in 156
> ms
> 
> __
> 
> ;; Received 501 bytes from 2001:500:3::42#53(l.root-servers.net) in 130
> ms
> 
> castmetrixcdn.net.      172800  IN      NS      ns1.castmetrixcdn.com.
> castmetrixcdn.net.      172800  IN      NS      ns2.castmetrixcdn.com.
> ;; Received 129 bytes from 192.26.92.30#53(c.gtld-servers.net) in 120
> ms
> 
> dig: couldn't get address for 'ns2.castmetrixcdn.com': not found
> 
> __
> 
> ;; Received 497 bytes from 2001:503:c27::2:30#53(j.root-servers.net) in
> 101 ms
> 
> castmetrixcdn.net.      172800  IN      NS      ns1.castmetrixcdn.com.
> castmetrixcdn.net.      172800  IN      NS      ns2.castmetrixcdn.com.
> ;; Received 129 bytes from 192.35.51.30#53(F.GTLD-SERVERS.net) in 168
> ms
> 
> austereo.castmetrixcdn.net. 3600 IN     A       66.186.49.74
> austereo.castmetrixcdn.net. 3600 IN     A       209.11.243.122
> austereo.castmetrixcdn.net. 3600 IN     A       66.186.45.186
> austereo.castmetrixcdn.net. 3600 IN     A       209.11.241.178
> castmetrixcdn.net.      3600    IN      NS      ns1.castmetrixcdn.com.
> ;; Received 197 bytes from 76.74.248.77#53(ns1.castmetrixcdn.com) in 154
> ms
> 

It depends on what NS record gets used. If it's ns2.castmetrixcdn.com, then it fails as shown above. 
If it's ns1.castmetrixcdn.com, then it resolves.


-- 
Haw Loeung
Systems Administrator
TPG Internet
http://www.tpg.com.au
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