Cisco Technology, Inc.

Sitaram Dontu

Michael R Smith

Faisal Mushtaq

Shreeram Bhide

Norman William Finn

Ali Golshan

Hiroshi Suzuki

Madhuri Kolli

Stefano Binetti

Chien Fang

Pagalavan Krishnamoorthy

Hemant K Hebbar

Nelson B D'Souza

Hemant Hebbar

Sheeram Bhide

Faisai Mushtaq

Mushtaq Faisal

Various methods and systems for preventing erroneous link aggregation due to component relocation are disclosed. Such methods include a method for changing the identifier used by a network device and communicating the identifier change to a peer network device without disrupting an aggregated link. In one embodiment, a method involves detecting an identifier change and sending a Port Aggregation Protocol (PAgP) protocol data unit (PDU) that includes a new identifier and information. The information indicates the identifier change. The new identifier identifies a network device subsequent to the identifier change. Another embodiment of a method involves detecting an identifier change and, subsequent to the identifier change, sending a link aggregation protocol PDU that includes an 'old device identifier' field dedicated to conveying an old identifier. The old identifier identifies a network device prior to the identifier change.

System and method for preventing erroneous link aggregation due to component relocation

Various systems and methods that allow multiple aggregation protocol sessions to be established in a daisy chain network are disclosed. One method involves sending a first aggregation protocol packet and a first session identifier associated therewith to a first network device via a first interface and sending a second aggregation protocol packet and a second session identifier associated therewith to a second network device via the first interface.

Multiple aggregation protocol sessions in a daisy chain network

A virtual network device sub-unit includes an interface to a virtual network device link and a distributed forwarding module. The interface receives a packet, and the distributed forwarding module forwards the packet received by the interface. The distributed forwarding module performs an ingress lookup if the packet includes a multicast destination address and an egress lookup if the packet includes a unicast destination address. If the packet includes a multicast destination address, the distributed forwarding module replicates the packet for each of several outgoing VLANs associated with the multicast destination address. If an additional multicast packet is received via an interface that is not coupled to a virtual network device link, the distributed forwarding module sends at most one copy of the additional multicast packet via the virtual network device link.

Distributed forwarding in virtual network devices

A virtual network device cluster includes several different virtual network device sub-units, which collectively operate as a single logical network device. The virtual network device cluster identifies the virtual network device sub-unit via which a given packet enters the virtual network device cluster. A packet is forwarded through the virtual network device cluster based on which virtual network device sub-unit has been identified for that packet. In one embodiment, a method involves receiving a packet via a first interface of a first one of several virtual network device sub-units of a virtual network device and associating the packet with the first one of the virtual network device sub-units. The method also involves inhibiting the packet from being sent via an interface of one of the virtual network device sub-units, in response to the packet being associated with the first one of the virtual network device sub-units.

Virtual network device clusters

Various methods and systems for detecting whether a network device supports a protocol, which defines a supplemental header, are disclosed. One method involves detecting a value within a preamble generated by a sending device and verifying that a header format of a header, also generated by the sending device, conforms to a header format definition of a protocol. The header format definition of the protocol defines a supplemental header. The preamble can be an Ethernet preamble. In one embodiment, the preamble is a converged data link (CDL) preamble or other type of preamble that is used to convey operation, administration and management (OAM) information.

Method and apparatus for detecting support for a protocol defining supplemental headers

Method and devices are provided for implementing high availability. Some implementations provide high availability for virtual switches of data networks. Each virtual switch acts as a single logical unit, while encompassing at least two physical chassis, referred to herein as a master chassis and a slave chassis. In some preferred embodiments, the active supervisor in the master chassis is configured as an active supervisor of the virtual switch and the active supervisor in the slave chassis is configured as the standby supervisor of the virtual switch.

High availability virtual switch

Growing community of inventors

Sunnyvale, CA, United States of America

Sitaram Dontu