1. A method for recovery from failure in a sending node in a data processing system which includes said sending node and at least one communications adapter coupled to the sending node, said method comprising: receiving at a receiving adapter of the data processing system a data packet transferred via remote direct memory access protocol from the sending node after restarting of the sending node, the data packet comprising a data packet header with a new key generated by the sending node, after restarting thereof, based on a random number seeded key generator, the new key being provided in a data structure of the data packet header of the data packet received by said receiving adapter; checking, by said receiving adapter, that the new key provided within the data structure of the data packet header of the data packet received by said receiving adapter matches a key loaded by a device driver into a table of a plurality of tables resident in a node in said data processing system coupled to said receiving adapter, the plurality of tables shared by the receiving adapter and one or more other adapters coupled to the node and mapping to memory buffers for remote direct memory access via the receiving adapter and the one or more other adapters, the data structure referencing the table of the plurality of tables, and the checking comprising using, by the receiving adapter, the data structure to reference the table of the plurality of tables to obtain the key loaded therein by the device driver; and responsive to the checking indicating a failed match, dropping the received data packet at the receiving adapter and signaling to the sending node that a fatal error has occurred with respect to the data packet transferred via remote direct memory access protocol.