International Business Machines Corporation

Lenovo (singapore) Pte. Ltd.

Venkatesh K Janakiraman

Colin Beaton Verrilli

Josep Cors

David Alan Shedivy

Claude Basso

Natarajan Vaidhyanathan

Joseph Allen Kirscht

Ethan M Spiegel

Sze-Wa Lao

Sameer M Shah

Techniques are disclosed for notifying network control software of new and moved source MAC addresses. In one embodiment, a switch may redirect a packet sent by a new or migrated virtual machine to the network control software as a notification. The switch does not forward the packet, thereby protecting against denial of service attacks. The switch further adds to a forwarding database a temporary entry which includes a 'No_Redirect' flag for a new source MAC address, or updates an existing entry for a source MAC address that hits in the forwarding database by setting the 'No_Redirect' flag. The &#x201c;No_Redirect&#x201d; flag indicates whether a notification has already been sent to the network control software for this source MAC address. The switch may periodically retry the notification to the network control software, until the network control software validates the source MAC address, depending on whether the &#x201c;No_Redirect&#x201d; is set.

Network control software notification and invalidation of static entries

Techniques are disclosed for notifying network control software of new and moved source MAC addresses. In one embodiment, a switch detects packets sent by a new or migrated virtual machine, and sends a copy of a detected packet to the network control software as a notification. The switch further learns the source MAC address, thereby permitting the entry to be used for normal forwarding prior to validation of the entry and the VM associated therewith by the network control software. Until the network control software has validated the VM, the switch may periodically retry the notification to the network control software. 'No_Redirect' and 'Not_Validated' flags may be used to indicate whether a notification has already been attempted and thus no retry is necessary, and that the VM associated with the VM has not yet been validated, respectively.

Network control software notification with advance learning

Techniques are provided for retrieving entries from a routing table or a forwarding database in a distributed network switch. The forwarding database includes match and mask registers used to compare routing entries and return matching routing entries to a requesting management controller. The forwarding database uses a separate timeout value associated with the forwarding database to avoid timeout errors for general register operations, and allows for an asynchronous dump operation of routing entries.

Smart dumping of network switch forwarding database

Growing community of inventors

Cupertino, CA, United States of America

Venkatesh K Janakiraman