Cisco Cisco Web Security Appliance S670 User Guide

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You can grant limited access to users who fail authentication due to invalid credentials. By 
default, when a client passes invalid authentication credentials, the Web Proxy continually 
requests valid credentials, essentially blocking access to all Internet resources. However, 
when you allow guest access, the first time the client passes invalid authentication 
credentials, the user is treated as a guest and the Web Proxy does not request authentication 
again.
You might want to grant guest access to users in the following situations:
• A visitor comes to the office and needs to be granted restrictive Internet access, but is not 
in the corporate user directory.
• An employee from another branch location (or from an acquired company) comes to the 
corporate headquarters, and needs Internet access. The user directories of the branch 
location (or acquired company) and corporate headquarters are separate, so the 
employee’s credentials do not work in the corporate headquarters.
• A new hire has been provided credentials in an email but they are not yet populated in 
the authentication server. 
• A user logs into a Windows workstation using a local account instead of a Windows 
domain account and the user needs access to the Internet.
The authentication server administrator in your organization can create a guest user account 
in the user directory. However, allowing guest access through the Web Security appliance has 
the benefit that the administrator does not have to communicate the guest credentials to every 
visitor.
To grant guest access to users who fail authentication, you create an Identity that requires 
authentication, but also allows guest privileges. Then you create another policy using that 
Identity and apply that policy to the guest users. When users who fail authentication have 
guest access, they can access the resources defined in the policy group that specifies guest 
access for that Identity.
A user who fails authentication has all transactions blocked if either of the following 
conditions are true:
• Guest privileges are not provided in any Identity.
• The user does not match any Identity that provides guest privileges.
A user who fails authentication has transactions allowed when all of the following conditions 
are true:
• The user matches an Identity with guest privileges.
• A non-Identity policy group uses that Identity and applies to guest users.
For example, you can create an Access or Decryption Policy that is specific to guest users.