Cisco Cisco Web Security Appliance S170 Guida Utente

When you create more than one realm, you can group the realms into an authentication sequence. An 
authentication sequence is a group of authentication realms listed in the order the Web Security 
appliance uses for authenticating clients. For more information about authentication sequences, see 

.

You configure some authentication options at a global level, independent of any realm. For more 
information, see 

By creating authentication realms and sequences, you can configure the Web Security appliance to use 
one or more authentication servers for authenticating clients on the network. For more information about 
how the appliance works when it uses multiple authentication servers, see 

.

After creating an authentication realm and possibly a sequence, too, you can create or edit Identities 
based on authentication realms or sequences. Note, however, that if you delete an authentication realm 
or sequence, any Identity group that depends on the deleted realm or sequence becomes disabled. For 
more information about using authentication with Identities, see 

.

When the Web Security appliance is deployed in transparent mode and a transaction requires 
authentication, the Web Proxy replies to the client application asking for authentication credentials. 
However, not all client applications support authentication, so they have no method for prompting users 
to provide their user names and passwords. These applications cannot be used when the Web Security 
appliance is deployed in transparent mode.

The following is a partial list of applications that do not work when the appliance is deployed in 
transparent mode:

Mozilla Thunderbird

Adobe Acrobat Updates

HttpBridge

Subversion, by CollabNet

Microsoft Windows Update

Microsoft Visual Studio

If users need to access a particular URL using one of these client applications, then create an Identity 
based on a custom URL category that does not require authentication and place the Identity above all 
other Identities that require authentication. When you do this, the client application will not be asked for 
authentication.

You can connect the Web Security appliance to an upstream proxy server. The upstream proxy server 
might be another Web Security appliance or a third party proxy. When the Web Security appliance is 
connected to an upstream proxy server, whether or not you can enable authentication depends on the 
authentication type: