vCenter Heartbeat provides rapid failover and failback on both physical and virtual platforms. It does this by monitoring VMware vCenter Server using the concept of active and passive server with same IP (Public IP) on both the servers.
Packet filter drivers are installed on a public network adapter during the installation of Heartbeat. Packet filter drivers make Public IP accessible from the active server by making it passthru and block it on the passive server. When switch-over or failover takes place it reverses the state of the packet filter.
Here is the packet filter enabled
You can check the state of your packet filter drivers using the command line. Navigate to the installation directory of vCenter Heartbeat and run nfpktfltr.exe gestate to see the status of drivers as shown:
Here it results passthru and this state of packets is on active server and public IP is accessible in the network. For passive servers the state of packet filter is filter and this means the Public IP is filtered for outside Network.
We can also install and uninstall packet filter drivers using the command line. Go to the install directory of vCenter Heartbeat and run nfpktfltr.exe uninstall
"<installdir>\VMware\VMware vCenter Server Heartbeat\r2\drivers\nfpktfltr\<HB version>"
For more information on installing and uninstalling the VMware vCenter Server Packet Filter Driver refer to KB article:
Installing and uninstalling the VMware vCenter Server Heartbeat packet filter driver (1009567).
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