| Event Id | 81 |
| Source | WLBS |
| Description | NLB Cluster %2 %1: NLB was unable to open the TCP connection callback object and will therefore be unable to track TCP connections. %3 %4 |
| Event Information | "According to Microsoft:Network Load Balancing (NLB) tracks TCP connections to ensure affinity to the host servicing the connection. If NLB cannot open a communication channel with the TCP/IP stack, it cannot guarantee, under certain conditions, that a given TCP connection is serviced by the same host for its duration. User Action: Try restarting the host. If restarting fails to establish communication with the TCP/IP stack, advanced users can force NLB to track TCP connections itself by setting the following REG_DWORD value to 0 (zero): HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\WLBS\Parameters\Global\EnableTCPNotification Note: The key will not exist by default. You must create it. You must restart the computer after making this change. This latter method of tracking TCP connections is less robust than using the TCP/IP stack, but it ensures TCP connection affinity in most cases. This method is not recommended if you are using multiple network adapters with asymmetric traffic flow (that is, using different network adapters to handle outbound vs. inbound NLB traffic)." |
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