Cisco Systems Authenticating Telnet Connections with a Virtual Server

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Cisco ASA 5500 Series Configuration Guide using ASDM
Chapter41 Configuring AAA Rules for Network Access
Configuring Authentication for Network Access
server; you are not prompted separately for the HTTP server username and password. Assuming the
username and password are 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 ASA. The ASA prompts for the AAA server username and password. After the AAA server
authenticates the user, the ASA 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 “Configuring Global Timeouts” section on
page 57-9.
You can authenticate directly with the ASA 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 ASA virtual server separately from the HTTP server, perform the
following steps:
Step1 From the Configuration > Firewall > Advanced > Virtual Access > Virtual HTTP Server area, check the
Enable check box.
Step2 In the Virtual HTTP Server field, add the IP address of the virtual HTTP server.
Make sure this address is an unused address that is routed to the ASA. 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.
Step3 (Optional) If you are using text-based browsers, where redirection does not happen automatically, check
the Display redirec tion warning check box. This enables an alert to notify users when the HTTP
connection is being redirected.
Step4 Click Apply.
The virtual server is added and the changes are saved to the running configuration.
Authenticating Telnet Connections with a Virtual Server
Although you can configure network access authentication for any protocol or service(see the
“Configuring Network Access Authentication” section on page 41-4), you can authenticate directly with
HTTP, Telnet, or FTP only. A user must first authenticate with one of these services before other traffic