This article describes a known issue with network connectivity in Microsoft Windows which can affect Neverfail Heartbeat software.
Windows 2000 / 2003 server with more than one NIC (with at least one NIC disabled).
After Windows update or installation of the Neverfail secondary server, the network is unable to communicate. This may affect one or more cards but in the case that this article is based on, only the public network was affected.
Clients are unable to connect to the machine when it is the active server (or tertiary server is unable to connect to cascade share when passive).
You may get a message on the screen when making changes to network connection properties about multiple gateways.
Unable to ping the IP address on the local machine (regardless of packet filter state you should always be able to ping this IP address locally). You may also be able to ping the host name.
Unable to browse the local shares via \\IPaddress but able to view shares via \\localhost
Net View [IP address] – may return an error 51 message.
This problem occurs when a disabled NIC has manually configured IP settings. The machine can sometimes attempt to use this card to send data instead of using another live NIC despite the fact that it is disabled.
This can happen to a machine which is working fine but has not been reconfigured in any way after windows update which requires a reboot.
Change the IP settings on the disabled NIC to use DHCP and make sure that it then has a 0.0.0.0 address and subnet configuration with no gateway.