74-8
Cisco ASA 5500 Series Configuration Guide using the CLI
Chapter74 Configuring Clientless SSL VPN
Using SSL to Access the Central Site
Configuring Support for Proxy Servers
The ASA can terminate HTTPS connections and forward HTTP and HTTPS requests to proxy servers.
These servers act as intermediaries between users and the Internet. Requiring Internet access via a server
that the organization controls provides another opportunity for filtering to assure secure Internet access
and administrative control.
When configuring support for HTTP and HTTPS proxy services, you can assign preset credentials to
send with each request for basic authentication. You can also specify URLs to exclude from HTTP and
HTTPS requests.
Restrictions
You can specify a proxy autoconfiguration (PAC) file to download from an HTTP proxy server, however,
you may not use proxy authentication when specifying the PAC file.
Command Purpose
Step1 webvpn Switches to webvpn configuration mode.
Step2 port port_number
Example:
hostname(config)# http server enable
hostname(config)# http 192.168.3.0 255.255.255.0
outside
hostname(config)# webvpn
hostname(config-webvpn)# port 444
hostname(config-webvpn)# enable outside
Changes the SSL listening port for clientless SSL
VPN.
Enables clientless SSL VPN on port 444 of the
outside interface. With this configuration, remote
users initiating clientless SSL VPN sessions enter
https://<outside_ip>:444 in the browser.
Step3 port argument of http server enable
Example:
hostname(config)# http server enable 444
hostname(config)# http 192.168.3.0 255.255.255.0
outside
hostname(config)# webvpn
hostname(config-webvpn)# enable outside
(Privileged exec mode) Changes the listening port
for ASDM.
Specifies that HTTPS ASDM sessions use port 444
on the outside interface. Clientless SSL VPN is also
enabled on the outside interface and uses the default
port (443). With this configuration, remote users
initiate ASDM sessions by entering
https://<outside_ip>:444
Command Purpose
Step1 webvpn Switches to webvpn configuration mode.
Step2 http-proxy and https-proxy Configures the ASA to use an external proxy server
to handle HTTP and HTTPS requests.
Note Proxy NTLM authentication is not
supported in http-proxy. Only proxy
without authentication and basic
authentication are supported.
Step3 http-proxy host [port] [exclude url] [username
username {password password}]