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Forum Discussion

Kayjay88's avatar
Kayjay88
Icon for Nimbostratus rankNimbostratus
Oct 21, 2025

Kerberos Authentication Failing for Exchange 2016 Behind F5 Cloud WAF

Hi Team,   We’re running Microsoft Exchange Server 2016 CU24 on Windows Server 2019, and have enabled Kerberos (Negotiate) authentication due to NTLM being deprecated in F5 Cloud WAF.   Environme...
authentication
cloud
email
exchange2016
management
Nikoolayy1's avatar
Nikoolayy1
Icon for MVP rankMVP
Oct 27, 2025

F5 XC does not support NTLM and probably it never will but in does Kerberos. I think http1.1 needed to be selected/hard coded between the client and XC and XC and origin servers. That is what I can share. XC on-boarding team should be also aware of this when you ask them this to be configured 😉