same subnet to connect to the program on the machine but drops traffic originating from a remote
network.
●
Advanced tab—Enables you to configure the following functions:
◦
Network Connection Settings: Select connection-specific rules which apply per network
interface.
◦
Security Logging: Create a log file for troubleshooting.
◦
ICMP: With Global Internet Control Message Protocol (ICMP) the computers on a network
can share error and status information.
◦
Default Settings: Restore Windows Firewall to a default configuration.
Gathering configuration information
To examine the current policy configuration for Windows Firewall, you can use the following command:
netsh firewall show configuration
.
Troubleshooting applications
Modifying an application to work with a stateful filtering firewall is the ideal way to resolve issues. This
is not always possible, so the firewall provides an interface for configuring exceptions for ports and
applications.
Identifying failure symptoms
Failures related to the default configuration will manifest in two ways:
●
Client applications may fail to receive data from a server. Examples include an FTP client,
multimedia streaming software, and new mail notifications in some e-mail applications.
●
Server applications running on the Windows Embedded computer may not respond to client
requests. Examples include a Web server such as Internet Information Services (IIS), Remote
Desktop, and File Sharing.
NOTE:
Failures in network applications are not limited to firewall issues. RPC or DCOM security
changes can cause failures. It is important to note whether the failure is accompanied by a Windows
Firewall Security Alert indicating that an application is being blocked.
Adding exceptions
With either of the failures mentioned above, you can add exceptions to the configuration for Windows
Firewall. Exceptions configure the firewall to permit specific inbound connections to the computer.
NOTE:
HP recommends adding a program instead of adding a port. Adding a program is easier and
safer than adding a port because you do not have to know which port numbers to use, and the port is
only open when the program is waiting to receive a connection. Only the specified application can use
the port, whereas opening a port allows any application to use it.
66
Chapter 10 Security
