Patent ID: 7428214

Claim:
A method of maintaining high availability in a network, the method comprising: determining that a virtual tracked interface has failed by examining an Extended Inter-switch Link (EISL) data frame, wherein the virtual tracked interface is a Virtual Storage Area Network (VSAN) interface, and if the virtual tracked interface is in a down state, dropping a corresponding physical link associated with the virtual tracked interface; determining that a first physical tracked interface has failed by examining routing table information from a network device having the first physical tracked interface, the first physical tracked interface forming a segment in a first data path between a first end device and a second end device; deriving a state of a linked interface of the network device from an operational state either of the virtual tracked interface or of the first physical tracked interface, wherein the linked interface and either the first physical tracked interface or the virtual tracked interface form part of the first data path between the first end device and the second end device; setting the state of the linked interface to the operational state of the first physical tracked interface or of the virtual tracked interface; applying a damping function to ensure that the state of the linked interface remains set to the virtual tracked interface state or to the first physical tracked interface state, thereby avoiding unnecessary switchover between the first data path and a second data path; notifying the first end device of the state of the linked interface; and switching to the second data path between the first end device and the second end device, thereby avoiding use of a keepalive message and shortening a time period needed for a keepalive timer period for switching to the second data path.