The adobe servers are just plain broken. Request a CNAME -> NXDOMAIN (Should return CNAME record) Request a TXT -> NXDOMAIN (Should return CNAME record) Request a NS -> NXDOMAIN (Should return CNAME record) Add a EDNS option -> NXDOMAIN (Should return CNAME record)
I suspect load balancer is passing non A/AAAA queries through to a backing server that doesn't have a fallback CNAME in the zone for ardownload.wip4.adobe.com resulting in NXDOMAIN being returned. That said, the load balancer should know that if it returning CNAME to A and AAAA queries, that it should also return CNAME to all other query types. This is basic RFC 1034 behaviour. Mark ; <<>> DiG 9.11.0pre-alpha <<>> ardownload.wip4.adobe.com cname @du1gtm001.adobe.com ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 201 ;; flags: qr aa rd; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1 ;; WARNING: recursion requested but not available ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 4096 ;; QUESTION SECTION: ;ardownload.wip4.adobe.com. IN CNAME ;; AUTHORITY SECTION: wip4.adobe.com. 30 IN SOA sj1gtm001.adobe.com. hostmaster.sj1gtm001.adobe.com. 1283 10800 3600 604800 60 ;; Query time: 486 msec ;; SERVER: 193.104.215.247#53(193.104.215.247) ;; WHEN: Tue Jul 08 12:15:41 EST 2014 ;; MSG SIZE rcvd: 111 ; <<>> DiG 9.11.0pre-alpha <<>> ardownload.wip4.adobe.com a @du1gtm001.adobe.com +nsid ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 37308 ;; flags: qr aa rd; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1 ;; WARNING: recursion requested but not available ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 4096 ;; QUESTION SECTION: ;ardownload.wip4.adobe.com. IN A ;; AUTHORITY SECTION: wip4.adobe.com. 30 IN SOA sj1gtm001.adobe.com. hostmaster.sj1gtm001.adobe.com. 1283 10800 3600 604800 60 ;; Query time: 422 msec ;; SERVER: 193.104.215.247#53(193.104.215.247) ;; WHEN: Tue Jul 08 12:17:30 EST 2014 ;; MSG SIZE rcvd: 111 ; <<>> DiG 9.11.0pre-alpha <<>> ardownload.wip4.adobe.com a @du1gtm001.adobe.com ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 37210 ;; flags: qr aa rd ad; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1 ;; WARNING: recursion requested but not available ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 4096 ;; QUESTION SECTION: ;ardownload.wip4.adobe.com. IN A ;; ANSWER SECTION: ardownload.wip4.adobe.com. 300 IN CNAME ardownload.adobe.com.edgesuite.net. ;; Query time: 441 msec ;; SERVER: 193.104.215.247#53(193.104.215.247) ;; WHEN: Tue Jul 08 12:15:57 EST 2014 ;; MSG SIZE rcvd: 102 In message <CAEKtLiQWZUifPX_bxGJh7uhQkRUiiG=+k-d54q2i_vebm6_...@mail.gmail.com> , Casey Deccio writes: > > On Wed, Jul 2, 2014 at 2:51 PM, Carl Byington <c...@byington.org> wrote: > > > -----BEGIN PGP SIGNED MESSAGE----- > > Hash: SHA1 > > > > version: 9.10.0-P2 > > > > dig ardownload.adobe.com. @localhost > > > > ;; ANSWER SECTION: > > ardownload.adobe.com. 8743 IN CNAME ardownload.wip4.adobe.com. > > > > > What is the rest of the dig output? Specifically, what status is your > resolver giving you (NOERROR or NXDOMAIN)? > > When queried for type NS, the adobe load balancer returns NXDOMAIN: > > $ dig @du1gtm001.adobe.com ardownload.wip4.adobe.com ns > > ; <<>> DiG 9.8.4-rpz2+rl005.12-P1 <<>> @du1gtm001.adobe.com > ardownload.wip4.adobe.com ns > ; (1 server found) > ;; global options: +cmd > ;; Got answer: > ;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 42533 > ;; flags: qr aa rd; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0 > ;; WARNING: recursion requested but not available > > ;; QUESTION SECTION: > ;ardownload.wip4.adobe.com. IN NS > > ;; AUTHORITY SECTION: > wip4.adobe.com. 30 IN SOA sj1gtm001.adobe.com. > hostmaster.sj1gtm001.adobe.com. 1283 10800 3600 604800 60 > > ;; Query time: 116 msec > ;; SERVER: 193.104.215.247#53(193.104.215.247) > ;; WHEN: Mon Jul 7 16:58:37 2014 > ;; MSG SIZE rcvd: 100 > > > Even though A queries yield NOERROR: > > $ dig @du1gtm001.adobe.com ardownload.wip4.adobe.com a > > ; <<>> DiG 9.8.4-rpz2+rl005.12-P1 <<>> @du1gtm001.adobe.com > ardownload.wip4.adobe.com a > ; (1 server found) > ;; global options: +cmd > ;; Got answer: > ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 21275 > ;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0 > ;; WARNING: recursion requested but not available > > ;; QUESTION SECTION: > ;ardownload.wip4.adobe.com. IN A > > ;; ANSWER SECTION: > ardownload.wip4.adobe.com. 300 IN CNAME > ardownload.adobe.com.edgesuite.net. > > ;; Query time: 119 msec > ;; SERVER: 193.104.215.247#53(193.104.215.247) > ;; WHEN: Mon Jul 7 16:59:25 2014 > ;; MSG SIZE rcvd: 91 > > Your cache might be adversely affected by this behavior if your cache is > sending NS queries to authoritative servers (for example, RPZ with NS > lookup), which would cause the name to be cached as NXDOMAIN. > > Casey > -- Mark Andrews, ISC 1 Seymour St., Dundas Valley, NSW 2117, Australia PHONE: +61 2 9871 4742 INTERNET: ma...@isc.org _______________________________________________ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users