DNS/索引/Verisignサーバについて、ここに記述してください。
http://www.verisigninc.com/en_US/innovation/dnssec/dns-behavior-changes/index.xhtml
- Changes to .COM/.NET/.EDU Name Servers in Preparation for DNSSEC
The two changes are New Referral Behavior and Glue No Longer Promoted to Authoritative Status.
https://lists.dns-oarc.net/pipermail/dns-operations/2010-January/004838.html