Applies to all Barracuda Web Filter appliances on all versions of firmware, when using Kerberos or NTLM authentication.
At this time, Office 2013 does not officially provide support for Kerberos or NTLM authentication. This creates an authentication failure when attempting to use Office 2013, since it will prompt for credentials and therefore ultimately fail. To bypass this incompatibility, Kerberos or NTLM authentication must be bypassed entirely.
1) In the Web Filter web interface, navigate to Advanced>Proxy.
2) Towards the bottom of the page, under Regular Expressions, click Bulk Edit.
3) Add the following entries to the Bulk Edit screen:^http://([^:/]*\.)office15client\.microsoft\.com/.*$4. Click Save.
Many customers have reported better success using Kerberos with Office 2013 over NTLM. Even after the implementation of the steps above, NTLM may still cause intermittent authentication prompts and it is suggested to switch to Kerberos authentication if possible.
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