The SIP security mode in Lync must be enabled.
An XCCDF Rule
Description
When Lync connects to the server, it supports various authentication mechanisms. This policy allows the user to specify whether Digest and Basic authentication are supported. Disabled (default): NTLM/Kerberos/TLS-DSK/Digest/Basic Enabled: Authentication mechanisms: NTLM/Kerberos/TLS-DSK Gal Download: Requires HTTPS if user is not logged in as an internal user.
- ID
- SV-223344r1043178_rule
- Version
- O365-LY-000001
- Severity
- Medium
- References
- Updated
Remediation Templates
A Manual Procedure
Set the policy value for Computer Configuration >> Administrative Templates >> Skype for Business 2016 >> Microsoft Lync Feature Policies "Configure SIP security mode" to "Enabled".