Cisco Technology, Inc.

Thomas W Uban

John Thomas Welder

Sudhir Rao

Ratheesh Krishna Vadhyar

Donald Edward Banks

Timothy Patrick Donahue

Denis Leclerc

A method and system for resetting a network device. Specifically, in one embodiment, a method is disclosed for upgrading and/or reloading software for a network device with minimal disruption. The method begins by separating operations associated with layer two of an International Standardization Organization Open Systems Interconnect (ISO/OSI) reference model from other layers in the ISO/OSI reference model in a network device. Then, the software operations in layer two of the network device are reset. The software operations are reset while maintaining continuity for a communication session between the network device and other network devices coupled together through a network. Thereafter, for minimal disruption, execution of the software operations is recovered at layer two before continuity of the communication session s terminated.

Method and system for minimal disruption during software upgrade or reload of a network device

A method is disclosed for providing interoperation of a first execution image of a first version and a second execution image of a second version. A compatibility matrix specifies whether the versions are compatible, base-level compatible, or incompatible. In one embodiment, the compatibility matrix may comprise a sparse table that stores a compatibility indicator for all permutations of a plurality of versions of a network operating system. As part of initialization of a system that includes the first execution image and second execution image, version information for the execution images is determined. An entry in the compatibility matrix corresponding to the versions is identified. The execution images are operated in a fully synchronized state when the identified entry of the compatibility matrix specifies that the versions are either compatible or base-level compatible. Individual components of the execution images interoperate according to the results of individual session negotiations. If the versions are incompatible, an alternative redundancy operation mode may be used. Embodiments provide for negotiation of compatible message versions and capabilities among peer components or clients of the execution images as source information to generate the compatibility matrix.

Method and apparatus providing interoperation of execution images of different versions

Growing community of inventors

Valpraiso, IN, United States of America

Thomas W Uban