same problem, more info.
#dig support.netapp.com
; <<>> DiG 9.8.1-P1 <<>> support.netapp.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 16142
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 4, ADDITIONAL: 4
;; QUESTION SECTION:
;support.netapp.com. IN A
;; ANSWER SECTION:
support.netapp.com. 30 IN A 216.240.18.16
;; AUTHORITY SECTION:
support.netapp.com. 554 IN NS dc1-gl01.netapp.com.
support.netapp.com. 554 IN NS dc2-gl01.netapp.com.
support.netapp.com. 554 IN NS dc2-gl02.netapp.com.
support.netapp.com. 554 IN NS dc1-gl02.netapp.com.
;; ADDITIONAL SECTION:
dc1-gl01.netapp.com. 10 IN A 202.3.113.55
dc1-gl02.netapp.com. 10 IN A 202.3.113.56
dc2-gl01.netapp.com. 10 IN A 216.240.31.245
dc2-gl02.netapp.com. 10 IN A 216.240.31.246
;; Query time: 42 msec
;; WHEN: Mon Apr 22 13:33:08 2013
;; MSG SIZE rcvd: 208
a subsequent dig on any of the dc*.netapp.com returns entries AAAA records:
#dig dc1-gl01.netapp.com | grep AAAA
ns021.netapp.com. 3184 IN AAAA 2620:10a:4001:4000::a28
ns060.netapp.com. 3184 IN AAAA 2620:10a:4003:4000::a221
#dig dc1-gl02.netapp.com | grep AAAA
ns021.netapp.com. 3177 IN AAAA 2620:10a:4001:4000::a28
ns060.netapp.com. 3177 IN AAAA 2620:10a:4003:4000::a221
#dig dc2-gl01.netapp.com | grep AAAA
ns021.netapp.com. 3169 IN AAAA 2620:10a:4001:4000::a28
ns060.netapp.com. 3169 IN AAAA 2620:10a:4003:4000::a221
#dig dc2-gl02.netapp.com | grep AAAA
ns021.netapp.com. 3166 IN AAAA 2620:10a:4001:4000::a28
ns060.netapp.com. 3166 IN AAAA 2620:10a:4003:4000::a221
#
always ns021 and ns060. My guess is that Netapp does not really have an ipv6 web presence as of yet, and those are two machines that were provisioned with v6 by mistake.. but that's just a guess.