Allowing ISP Heartbeat messages
Internet Service Providers (ISPs) periodically send heartbeat messages to their connected dial-up customers to make sure they are still there. If the ISP cannot determine that the customer is there, it might disconnect them so that the IP address can be given to someone else.
By default, ZoneAlarm security software blocks the protocols most commonly used for these heartbeat messages, which may cause you to be disconnected from the Internet.
To prevent this from happening, you can identify the server sending the messages and add it to your Trusted Zone or you can configure the Public Zone to allow ping messages, using one of these methods:
- Identifying the source of heartbeat messages (more secure)
- Configuring ZoneAlarm security software to allow ping messages