Kerio Personal Firewall can detect and block changes of telephone numbers of dialed lines. This protects users from undesirable redirecting of dial-ups to high-price services. Connections may be redirected without letting the user know (for example by an ActiveX object on a Web page). If a change of a telephone number is detected, Kerio Personal Firewall asks user to accept or reject the change. If the change is rejected, the line is hung-up immediately. Thanks to this feature, users are protected from undesirable and expensive connections.
Upon the first unknown dial-up connection, the firewall asks user whether the interface is connected to a trustworthy network (like in case of a new network adapter — see chapter 7.4. Trusted Area). The dial-up will be considered as an interface in the Network security / Trusted zone section.
After the user is asked whether the adapter should be accepted to the trusted zone, a dialog providing information on the new telephone number is opened.
In this dialog, user can set various parameters of the interface as well as the way the firewall will behave upon a change of a dial-up number.
The following options are available for the Dialup number item:
Ask — whenever a number is dialed, Kerio Personal Firewall asks user to accept or reject this number. If the change is accepted, the firewall remembers this dial-up number. Otherwise, the line is hung-up immediately.
If the new number is accepted, the Always use this number alternative is selected automatically and the number is saved.
Always use this number — this option makes the firewall suppose that the dial-up number is not to be changed. Whenever a change of the dial-up number is detected, the New dial-up number dialog is displayed and the user is asked to accept or reject the change.
The Dial-up number item provides the new telephone number (the number which is currently set for the dial-up connection). The Adapter item provides a name of the dial-up connection.
Click to make Kerio Personal Firewall accept the number, allow for dialing the line and remember the new number, or to reject the change and hang up the line.
Do not monitor number change — the firewall ignores changes of the dial-up number and always permits the line to be dialed. This option can be used for example for testing.
Warning: This option is not secure (the firewall does not detect possible changes of the dial-up number) and it is not recommended to use it for the default dial-up connection!
