Abstract: In a first aspect, a first method is provided for creating a media access control (MAC) address for a device. The first method includes the steps of (1) obtaining one or more identifiers; (2) obtaining a first MAC address; and (3) creating at least a second MAC address based on the one or more identifiers and the first MAC address. Numerous other aspects are provided.

Abstract: A system and method to manage device access in a software partition are provided. The illustrative embodiments provide a mechanism for exporting resources/devices from an administrator partition to a software partition in its purview. A trusted device list data structure is provided that identifies which devices are permitted to be exported into a software partition from an administrative partition. This trusted device list data structure also identifies which of the devices in the list of devices should be exported by default when exporting devices to a software partition, i.e. if no overrides are specified. In addition, a user-specifiable mechanism to override the entries in the trusted device list data structure is provided. For security purposes, this mechanism may not be used to export devices not listed in the trusted device list data structure. The mechanism may also be used to prevent the exporting of devices which are exported by default.

Abstract: A method, apparatus, and computer instructions for handling intrusions. A tracer packet is sent back to an intruder causing the intrusion in response to receiving notification of an intrusion from a particular node in a network data processing system. Nodes in the network data processing system are notified of the tracer packet. Identification of the node is stored for use in tracing a route of the tracer packet through the data processing system in response to receiving a message from a node indicating receipt of the tracer packet.

Abstract: The present invention provides receiving and transmitting devices for providing fragmentation at a transport level along a transmission path. The transmitting device comprises an interface and a control unit coupled to the interface. The control unit is adapted to negotiate a packet size with a remote device. The control unit is also adapted to transmit a data packet of up to the negotiated size. The control unit is further adapted to receive acknowledgments from the remote device associated with one or more fragments, fragmented at the transport-level, of the transmitted data packet. The receiving device comprises an interface and a control unit coupled to the interface. The control unit is adapted to receive two or more fragments of a data packet transmitted by a remote device. The control unit is also adapted to transmit one or more acknowledgments to the remote device based on the received fragments.

Abstract: A computer implemented method, apparatus, and computer program product for managing state data in a workload partitioned environment. Process state data for a process in a workload partition is saved. Process state data is used to restore the process to a given state. State data associated with open sockets and open files bound to the first process is saved. In response to a determination that the process is associated with a domain socket that is bound to a socket file, an absolute pathname for the socket file is saved. A domain socket associated with a connecting process in the workload partition uses the socket file to connect to a domain socket associated with a listening process in the same workload partition to enable the two processes to communicate with each other.

Abstract: A computer-implemented method, an apparatus, and a computer-usable program product for identifying a link status for a virtual adapter in a logical partition framework are provided. A partition management firmware receives a signal identifying a communication disruption in a link associated with the virtual adapter within the logical partition framework. The partition management firmware identifies which links associated with the virtual adapter are affected by the communication disruption. Responsive to identifying that only a physical link associated with the virtual adapter is disrupted, the partition management firmware categorizes the link status for the virtual adapter as partial link-down. Responsive to identifying that both the physical link and a virtual link associated with the virtual adapter are disrupted, the partition management firmware categorizes the link status for the virtual adapter as link-down.

Abstract: A NAT data processing system is located behind a NAT enabled network with a NAT device as a gateway to the NAT enabled network. A client system located outside the NAT enabled network queries the NAT device for the address of the NAT data processing system located behind the NAT enabled network. The query is automatically routed through the NAT device to a DNS server. The DNS server then returns an address for the NAT data processing system and source routing for the NAT device. The NAT device forwards the address and source routing to the client system. Then, the client system sends packets to the NAT data processing system at the address with source routing through the NAT device, such that the NAT data processing system behind the NAT enabled network is directly accessed by the client system from outside the NAT enabled network.

Abstract: Methods, systems, and products are provided for tunneling IPv6 packets. Embodiments include receiving, by an origin IPv6 border router from an origin IPv6 host, an IPv6 packet having an IPv6 destination address; receiving, by an origin IPv6 border router from an origin IPv6 host, an IPv4 address for a destination IPv6 border router retrieved from a data structure associating IPv6 destination addresses with IPv4 addresses for destination IPv6 border routers; encapsulating, by the origin IPv6 border router, the IPv6 packet in an IPv4 packet; and sending the encapsulated packet to a destination IPv6 border router at the IPv4 address. In many embodiments, encapsulating, by the origin IPv6 border router, the IPv6 packet in an IPv4 packet is carried out by adding an IPv4 header to the IPv6 packet.

Abstract: TCP congestion avoidance is implemented upon retransmission of a packet and is reverted back to the original congestion state upon receipt of an early acknowledgement (ACK), indicating reordering of packets, thereby eliminating a needless restriction on TCP bandwidth. Upon receiving an ACK to a retransmitted packet, it is determined if the ACK resulted from receipt of the original reordered packet or the retransmitted packet, based on the arrival time of the ACK at the sender. If the round-trip-time (RTT) for the retransmitted packet is much lower than the average or current calculated RTT for the network link between sender and receiver, then the retransmission occurred as a result of a reordering event, and the congestion window is restored back to its value prior to the retransmission, thereby permitting the network link to continue operating at its original increased throughput.

Abstract: In a first aspect, a first method is provided for creating a media access control (MAC) address for a device. The first method includes the steps of (1) obtaining one or more identifiers; (2) obtaining a first MAC address; and (3) creating at least a second MAC address based on the one or more identifiers and the first MAC address. Numerous other aspects are provided.

Abstract: A method, system, and product are described for alleviating router congestion when the router is processing packets transmitted by computer systems having a congestion notification capability. The router marks packets transmitted between a first computer system and a second computer system when the first and second computer systems have the congestion notification capability. The marking indicates that the router is moderately congested. A marked packet is then received by the first computer system. The router then drops packets transmitted by the first computer system when the packets were transmitted subsequent to the receipt of the marked packet.

Abstract: A data processing system for resending a previously sent email message. A new recipient for the previously sent email message is selected. The new recipient of the previously sent email message is added in response to selecting the new recipient, wherein the previously sent email message is directed to the new recipient and a previous recipient. An indicator to the previously sent email message is added in response to selecting the new recipient, wherein the indicator indicates that the new recipient has been added to a form a new version of the previously sent email message. The new version of the previously sent email message is sent in response to adding the indicator, wherein the indicator causes the new version of the previously sent email message to replace the previously sent email message at an email program of the previous recipient.

Abstract: In one embodiment a method for migrating a workload from one processing resource to a second processing resource of a computing platform is disclosed. The method can include a command to migrate a workload that is processing and the process can be interrupted and some memory processes can be frozen in response to the migration command. An index table can be created that identifies memory locations that determined where the process was when it is interrupted. Table data, pinned page data, and non-private process data can be sent to the second processing resource. Contained in this data can be restart type data. The second resource or target resource can utilize this data to restart the process without the requirement of bulk data transfers providing an efficient migration process. Other embodiments are also disclosed.

Abstract: A computer implemented method, data processing system, and computer program product for enabling the restoration of in-flight file descriptors during a checkpoint operation. Responsive to a checkpoint operation being initiated on a process in a workload partition, in-flight file pointers in an in-flight file queue on a socket bound to the process are identified. A file descriptor is instantiated in the process file table of the process for each identified in-flight file pointer in the in-flight file queue. After completion of the checkpoint operation, the in-flight file queue on the socket may be reconstructed in a restore operation using the instantiated file descriptors.

Abstract: A method, apparatus, and computer instructions for processing a data packet in an interpartition virtual network in the logical partitioned data processing system. A state of a first flag and a state of a second flag is identified in the data packet, in response to receiving the data packet at a first partition in the interpartition virtual network from a second partition in the interpartition virtual network in the logical partitioned data processing system. A checksum is selectively verified for the data packet based on the state of the first flag and the state of the second flag.

Abstract: A method, system, and computer program product for delivering data, received from a network on a network adapter to a pre-assigned port, to a storage buffer assigned to an application are disclosed. An application designates an application-specific buffer within a local data processing system for buffering data communicated with the application. The local data processing system reports to a network interface of the local data processing system a memory address of the designated application-specific buffer, and the data processing system designates a port on which to receive packets addressed to the memory address. The data processing system then sends a port registration message to the local network interface, enabling the network interface to compare the port number of incoming traffic to a registered port number and route incoming traffic from a remote data processing system directly to the designated application-specific buffers in the event of a match.

Abstract: A method, system, and program provide for efficient send socket call handling by a transport layer. A transport layer of a network protocol stack receives a send socket call for data of a specified length from an application layer. Responsive to detecting that there is insufficient memory for a single memory allocation to a buffer in the transport layer for at least the specified length, the transport layer blocks the send socket call. The transport layer only wakes the send socket call upon detection of sufficient memory for the single memory allocation within the buffer of the transport layer for at least the specified length, wherein waking the send socket call triggers a kernel to perform the single memory allocation in the buffer and to write the data to the single memory allocation in a single pass.

Abstract: A method, system, and program for monitoring thread usage to dynamically control a thread pool are provided. An application running on the server system invokes a listener thread on a listener socket for receiving client requests at the server system and passing the client requests to one of multiple threads waiting in a thread pool. Additionally, the application sends an ioctl call in blocking mode on the listener thread. A TCP layer within the server system detects the listener thread in blocking mode and monitors a thread count of at least one of a number of incoming requests waiting to be processed and a number of said plurality of threads remaining idle in the thread pool over a sample period. Once the TCP layer detects a thread usage event, the ioctl call is returned indicating the thread usage event with the thread count, such that a number of threads in the thread pool may be dynamically adjusted to handle the thread count.

Abstract: A method, system, and computer program product in a computer-readable medium for delivering data, received from a network, to a storage buffer assigned to an application is proposed. An application designates a communication buffer within a local data processing system for buffering data communicated with an application. The local data processing system reports to a network interface of the local data processing system a memory address of the designated communication buffer, and the data processing system creates a cookie containing the memory address. The data processing system then sends the cookie form the local data processing system to a remote data processing system, such that the remote data processing system may address data directly to the designated communication buffer.

Abstract: A method and apparatus is provided for enabling a telephone caller to generate a brief message for transmission to an intended call recipient, as part of the initial procedure of setting up a phone call between the caller and recipient. The message is sent and displayed or otherwise made available to the recipient before the recipient is required to answer the call. The message could comprise a sequence of alphanumeric characters that conveyed an abbreviated message, or otherwise indicates the purpose to the call to the recipient or provides other information. Respective characters could be transmitted as corresponding sequences of binary tones sent to the call recipient between telephone rings.