Ironically enough, an Apple tool designed to deliver zero-configuration networking to Windows clients manages to kill off Internet access for Windows Vista Service Pack 2, according to Microsoft. The Redmond company indicated that all Vista editions could be affected, whether from the RTM, SP1 or SP2 releases. In certain scenarios, installing the Apple Bonjour on a Vista machine causes the service to create a default gateway of 0.0.0.0. Microsoft pointed the finger at Bonjour and the service's logic used to add a route designed to identify a default gateway, which, if set incorrectly to 0.0.0.0, is not removed subsequently, even if the correct connection data is provided via DHCP.

The software giant explained that the problems were related to Vista computers that did “not receive an address through DHCP prior to the Bonjour service start. Under this condition, the Bonjour service adds a default route to the computer indicating that all internet hosts are “onlink”. The computer is subsequently able to receive an address through DHCP. Bonjour does not remove the default route, leaving an incorrect default gateway configured on the machine. This gateway usurps the proper gateway configuration DHCP provides and prevents Internet access.”

There is no update or hotfix from Microsoft or Apple designed to resolve this issue. The Redmond company did however provide end users with the guidance necessary to manually remove the erroneous route. End users will have to open command prompt with elevated privileges. In cmd, running the following command “route delete 0.0.0.0” will delete the route created by Bonjour.

Microsoft emphasized that manually removing route 0.0.0.0 could be nothing more than a temporary solution. While Vista will indeed be able to regain Internet access, the problem could repeat itself. “This does not ensure that the Bonjour service will never create the route again as this depends on the sequence of events under ‘Cause’ occurring,” the company said. In this context, users will simply need to run the “route delete 0.0.0.0” command yet again.

Here is what Bonjour should do, according to Apple: "Bonjour, also known as zero-configuration networking, enables automatic discovery of computers, devices, and services on IP networks. Bonjour uses industry standard IP protocols to allow devices to automatically discover each other without the need to enter IP addresses or configure DNS servers. Specifically, Bonjour enables automatic IP address assignment without a DHCP server, name to address translation without a DNS server, and service discovery without a directory server."