Cisco Systems Closing Application Access to Prevent hosts File Errors, Recovering from hosts File Errors When Using Application Access

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Cisco ASA 5500 Series Configuration Guide using ASDM
Chapter72 Configuring Clientless SSL VPN
Application Access User Notes
Closing Application Access to Prevent hosts File Errors
To prevent hosts file errors that can interfere with Application Access, close the Application Access
window properly when you finish using Application Access. To do so, click the close icon.
Recovering from hosts File Errors When Using Application Access
The following errors can occur if you do not close the Application Access window properly:
•The next time you try to start Application Access, it might be disabled; you receive a Backup HOSTS
File Found error message.
•The applications themselves might be disabled or might malfunction, even when you are running
them locally.
These errors can result from terminating the Application Access window in any improper way. For
example:
•Your browser crashes while you are using Application Access.
•A power outage or system shutdown occurs while you are using Application Access.
•You minimize the Application Access window while you are working, then shut down your
computer with the window active (but minimized).
This section includes the following topics:
•Understanding the hosts File
•Stopping Application Access Improperly
•Reconfiguring a Host’s File Automatically Using Clientless SSL VPN
•Reconfiguring hosts File Manually
Understanding the hosts File
The hosts file on your local system maps IP addresses to host names. When you start Application Access,
clientless SSL VPN modifies the hosts file, adding clientless SSL VPN-specific entries. Stopping
Application Access by properly closing the Application Access window returns the file to its original
state.
Before invoking Application Access... hosts file is in original state.
When Application Access starts.... •Clientless SSL VPN copies the hosts file to
hosts.webvpn, thus creating a backup.
•Clientless SSL VPN then edits the hosts file,
inserting clientless SSL VPN-specific
information.
When Application Access stops... •Clientless SSL VPN copies the backup file to
the hosts file, thus restoring the hosts file to
its original state.
•Clientless SSL VPN deletes hosts.webvpn.
After finishing Application Access... hosts file is in original state.