NDB Cluster Configuration Files To identify a connection between two nodes it is necessary to provide their node IDs in the  [tcp] section of the configuration file as the values of  NodeId1  and  NodeId2 . These are the same unique  Id values for each of these nodes as described in Section 23.3.3.7, “Defining SQL and Other API Nodes in an NDB Cluster” . When more than this many unsent bytes are in the send buffer, the connection is considered overloaded. This parameter can be used to determine the amount of unsent data that must be present in the send buffer before the connection is considered overloaded. See Section 23.3.3.14, “Configuring NDB Cluster Send Buffer Parameters” , for more information. Determines the preference of DNS resolution for IP version 4 or version 6. Because the configuration retrieval mechanism employed by NDB Cluster requires that all connections use the same preference, this parameter should be set in the  [tcp default]  of the  config.ini  global configuration file. If this parameter and  Checksum  are both enabled, perform pre-send checksum checks, and check all TCP signals between nodes for errors. Has no effect if  Checksum  is not also enabled. Default [none] Range 1 - 255 Restart Type N (NDB 8.0.13) Version (or later) NDB 8.0.13 Type or units bytes Default 0 Range 0 - 4294967039 (0xFFFFFEFF) Restart Type N (NDB 8.0.13) Version (or later) NDB 8.0.26 Type or units enumeration Default 4 Range 4, 6 Added NDB 8.0.26 Restart Type IS (NDB 8.0.13) Version (or later) NDB 8.0.13 Type or units boolean Default false Range true, false Restart Type N (NDB 8.0.13) • PreSendChecksum • PreferIPVersion • OverloadLimit 4222