Cisco ASA 5505 Configuration Manual page 706

Configuring Authentication for Network Access
If the destination HTTP server requires authentication in addition to the adaptive security appliance, then
virtual HTTP lets you authenticate separately with the adaptive security appliance (via a AAA server)
and with the HTTP server. Without virtual HTTP, the same username and password you used to
authenticate with the adaptive security appliance is sent to the HTTP server; you are not prompted
separately for the HTTP server username and password. Assuming the username and password is not the
same for the AAA and HTTP servers, then the HTTP authentication fails.
This feature redirects all HTTP connections that require AAA authentication to the virtual HTTP server
on the adaptive security appliance. The adaptive security appliance prompts for the AAA server
username and password. After the AAA server authenticates the user, the adaptive security appliance
redirects the HTTP connection back to the original server, but it does not include the AAA server
username and password. Because the username and password are not included in the HTTP packet, the
HTTP server prompts the user separately for the HTTP server username and password.
For inbound users (from lower security to higher security), you must also include the virtual HTTP
address as a destination interface in the Access Rule applied to the source interface. Moreover, you must
add a static NAT rule for the virtual HTTP IP address, even if NAT is not required. An identity NAT rule
is typically used (where you translate the address to itself).
For outbound users, there is an explicit permit for traffic, but if you apply an Access Rule to an inside
interface, be sure to allow access to the virtual HTTP address. A static NAT rule is not required.
Note Do not set the uauth timeout duration to 0 seconds when using virtual HTTP, because this setting
prevents HTTP connections to the real web server. See the
page 48-9.
You can authenticate directly with the adaptive security appliance at the following URLs when you
enable AAA for the interface:
http://interface_ip[:port]/netaccess/connstatus.html
https://interface_ip[:port]/netaccess/connstatus.html
To allow users to authenticate with the adaptive security appliance virtual server separately from the
HTTP server, perform the following steps:
From the Configuration > Firewall > Advanced > Virtual Access > Virtual HTTP Server area, check the
Step 1
Enable check box.
In the Virtual HTTP Server field, add the IP address of the virtual HTTP server.
Step 2
Make sure this address is an unused address that is routed to the adaptive security appliance. For
example, if you perform NAT for inside addresses accessing an outside server, and you want to provide
outside access to the virtual HTTP server, you can use one of the global NAT addresses for the virtual
HTTP server address.
(Optional) If you are using text-based browsers, where redirection does not happen automatically, check
Step 3
the Display redirection warning check box. This enables an alert to notify users when the HTTP
connection is being redirected.
Click Apply.
Step 4
The virtual server is added and the changes are saved to the running configuration.
Cisco ASA 5500 Series Configuration Guide using ASDM
33-8
Chapter 33 Configuring AAA Rules for Network Access
"Configuring Global Timeouts" section on
OL-20339-01