Issue 1

Name resolution for some external websites fails on a Windows Server 2012-based DNS server that uses Internet root hints.

Issue 2

An incorrect Canonical Name (CNAME) record is returned by the DNS server when it processes an answer that contains a Delegation Name (DNAME) record.

Issue 3

Assume that you use Name Authority Pointer (NAPTR) records in your environment to locate Session Initiation Protocol (SIP) services for telephones. However, because the Windows Server 2012-based DNS server compresses NAPTR records, telephones cannot locate SIP services.

Cause of issue 1

This issue occurs because the authoritative server for the website has both a start of authority (SOA) record and a CNAME record on the website. This prevents the DNS server from resolving domain names correctly.


To fix this issue, install MS15-127: Security updates for Microsoft Windows DNS to address remote code execution: December 8, 2015.


Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.


Learn about theĀ terminology that Microsoft uses to describe software updates.

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