Cisco Technology, Inc.

Google Inc.

Tameen Khan

Ronak K Desai

Sanjay Sane

Dino Farinacci

Umesh Mahajan

Ramana Mellacheruvu

Saurabh Jain

Amitkumar V Patel

Norman William Finn

Victor Manuel Moreno

Francois Edouard Tallet

Munish Mehta

Douglas Alan Gourlay

Shibani Sanan

Santosh Rajagopalan

Shekher Bulusu

Mark Berly

Laura Werner

Sandor Miklos Szego

Jun Lu

Robert Spier

Systems and method of automated master election for high availability database system are discussed herein. Automated lock competition and master worker selection based on factors that may include geographic parameters, processing power, connection speed, and relative locations of database(s) and worker(s) are also discussed.

Preferred master election

In one embodiment, a first switch is located at a first border between first networks that utilize a STP to detect and break loops and second networks. The first switch is interconnected via the first networks with a second switch located at a second border between the first networks and the second networks. The first switch detects, via a protocol other than STP, addition of a link in the second networks that provides a new path across the second networks between the first switch and the second switch. The first switch blocks data packets from traversing through one or more network boundary ports of the first switch coupled to the first networks, while allowing STP BPDUs to traverse through the one or more network boundary ports, for a period of time sufficient for the first networks to discover the new path using STP.

Transient loop prevention in a hybrid layer-2 network

A method and apparatus for preventing loops in a network with network devices operating a spanning tree protocol and network devices operating a link state routing protocol to prevent loops are disclosed. In one embodiment, a method includes receiving from one of the network devices operating a link state protocol, a link state routing synchronization packet at a first network device in communication with one of the network devices operating the spanning tree protocol, blocking at the first network device, boundary ports in communication with the network devices operating the spanning tree protocol, transmitting a link state routing synchronization acknowledgement packet at the first network device after the boundary ports are blocked, and performing a loop-free topology convergence process at the first network device.

Preventing loops in networks operating different protocols to provide loop-free topology

A system and method runs a multiple spanning tree protocol (MSTP) in a computer network having a very large number of bridge domains. The computer network includes a plurality of intermediate network devices, each having a plurality of ports for forwarding network messages. Within each device, a plurality of bridge domains are defined, each bridge domain is identified by a Virtual Local Area Network (VLAN) Identifier (VID), and one or more device ports. For each port, a separate mapping of VIDs to Multiple Spanning Tree Instances (MSTIs), based on the bridge domains defined at the port, is established. Each mapping is converted to a port-based configuration digest, which is entered into Spanning Tree Protocol (STP) control messages sent from the respective port. Ports receiving STP control messages whose configuration digest values that match the configuration digests values computed for the ports are said to be in the same Multiple Spanning Tree region. Ports whose configuration digests differ from the configuration digests of received STP control messages are said to be in different regions.

System and method for running a multiple spanning tree protocol with a very large number of domains

In one embodiment, a technique for routing traffic in networks represented by logical topologies, such as Multi Chassis Port Channel (MCPC) or Multi Chassis Ether Channel (MCEC) topologies, is provided. By modifying a port priority vector (PPV) to include an additional 'Switch ID' field that identifies a designated bridge ID or a local switch ID, depending on whether the corresponding port is used as an MCT, a routing protocol designed to avoid loops in routing paths, such as STP, may avoid blocking MCT ports.

Distributed spanning tree protocol on a multi chassis port channel

In one embodiment, when a network element is to be removed from or inserted into a network a Graceful Operations Manager schedules graceful shut-down and/or start-up routines for different protocols and/or components on the network element in an optimal order based on dependencies between the different protocols and components. The Graceful Operations Manager communicates with the different components at different stages of their shut-down or start-up process and communicates information on the standby topology across components and/or protocols to enable the synchronization of the standby topology computation on all components and/or protocols that are affected by the removal or insertion.

Graceful removal and/or insertion of a network element

In one embodiment, a first switch at a border between a first network of a first protocol (P1 network) and a first network of a second protocol (P2 network) is interconnected via the first P1 network with a second switch between a second P1 network (interconnected with the first P1 network) and a second P2 network. In response to detecting a merge of the first and second P2 networks, the first switch may: i) block data packets from traversing P1 network boundary ports of the first switch; ii) allow protocol messages to flow between the first and second P1 networks through the P1 network boundary ports of the first switch; iii) allow the first and second P1 networks to discover each other through the protocol messages and to prevent loops; and in response, iv) unblock the P1 network boundary ports of the first switch to allow traversal of data packets.

In one embodiment, a method includes receiving at a processor at a node, notification of an error in a VLAN to topology mapping at the node, receiving a multi-destination packet from the VLAN in the VLAN to topology mapping, the multi-destination packet including a tree identifier associated with one of the topologies, and transmitting the multi-destination packet to all forwarding ports at the node in an unpruned tree corresponding to the tree identifier contained in the multi-destination packet. An apparatus is also disclosed.

Preventing loss of network traffic due to inconsistent configurations within the network

A method and system for preventing loops in a network including network devices operating different protocols for providing loop-free topology are disclosed. In one embodiment, a method includes receiving link state information at a network device operating a first protocol and in communication with a network device operating a second protocol, creating at least one tunnel to one or more other network devices operating the first protocol and in communication with a network device operating the second protocol, receiving a proposal, blocking designated boundary ports in communication with network devices operating the second protocol, and transmitting an agreement.

Disclosed are methods and apparatus for restarting a first network device having a plurality of ports for receiving and transmitting layer 2 data. The first network device belongs to a network of network devices. When a restart of at least a portion of the first network device is imminent whereby the restarting network device portion can no longer alter a spanning tree protocol (STP) state of one or more of the ports and such ports that remain in a fixed state during the restart are referred to as restarting ports, a current state (such as forwarding) of each restarting port is maintained during the restart under predefined conditions. During the restart, each of the restarting ports of the restarting network device portion cooperate with its peer port of a second non-restarting network device that is a neighbor of the first network device so as to prevent layer 2 loops in the network.

Seamless spanning tree upgrade of a linecard

Disclosed are methods and apparatus for restarting a first network device having a plurality of ports for receiving and transmitting layer 2 data. The first network device belongs to a network of network devices. When a restart of at least a portion of the first network device is imminent whereby STP is no longer functioning for the first network device during the restart and can no longer alter a spanning tree protocol (STP) state of one or more of the ports and such ports that remain in a fixed state during the restart are referred to as restarting ports, a current state (such as forwarding) of each restarting port is maintained during the restart under predefined conditions. During the restart, each of the restarting ports of the restarting network device portion cooperate with its peer port of a second non-restarting network device that is a neighbor of the first network device so as to prevent layer 2 loops in the network.

Growing community of inventors

Santa Clara, CA, United States of America

Tameen Khan