# US 2014/0153385 A1 · Redundant host connection in a routed network > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0153385 A1 - Document ID: US20140153385A1 - Status: Published application - Kind: A1 - Application number: 14/172,683 - Filed: 2014-02-04 - Published: 2014-06-05 - Earliest claimed: 2009-03-26 - Assignees: Brocade Communications Systems, Inc. - Applicants: Brocade Communications Systems, Inc. - Inventors: Somesh Gupta; Anoop Ghanwani; Phanidhar Koganti; Shunjia Yu - Web page: https://patentgrep.com/patent/US20140153385A1 ## CPC - H04L 12/4625: {Single bridge functionality, e.g. connection of two networks over a single bridge} - H04L 45/28: using route fault recovery - H04L 45/48: Routing tree calculation - H04L 45/586: of virtual routers - H04L 45/66: {Layer 2 routing, e.g. in Ethernet based MAN's} - H04L 45/76: Routing in software-defined topologies, e.g. routing between virtual machines - H04L 49/557: {Error correction, e.g. fault recovery or fault tolerance} - H04L 49/65: Re-configuration of fast packet switches - H04L 49/70: {Virtual switches} - H04L 49/201: Multicast operation; Broadcast operation - H04L 49/351: for local area network [LAN], e.g. Ethernet switches - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract One embodiment of the present invention provides a switch. The switch includes a management mechanism and a configuration mechanism. During operation, the management mechanism is configured to operate the switch in conjunction with the partner switch as a single logical switch. The configuration mechanism is configured to assign a virtual switch identifier to the logical switch. ## Claims ### Claim 1 A switch, comprising: a processor; a memory coupled to the processor and storing instructions which when executed cause the processor to: form a single logical switch with a separate physical switch, wherein the logical switch is assigned a virtual switch identifier; and mark an ingress-switch field of a frame with the virtual switch identifier. ### Claim 2 (depends on 1) The switch of claim 1, wherein the switch is a layer-2 switch capable of routing without requiring the network topology to be based on a spanning tree topology. ### Claim 3 (depends on 1) The switch of claim 1, wherein the switch is a routing bridge configured to operate in accordance with the Transparent Interconnection of Lots of Links (TRILL) protocol. ### Claim 4 (depends on 1) The switch of claim 1, wherein the memory further stores instructions which when executed cause the processor to set the cost of a link to the logical switch to be zero. ### Claim 5 (depends on 1) The switch of claim 1, wherein the memory further stores instructions which when executed cause the processor to mark an ingress-switch field of a frame with the virtual switch identifier, wherein the frame is received from a device coupled to the switch. ### Claim 6 (depends on 1) The switch of claim 1 wherein the memory further stores instructions which when executed cause the processor to notify the separate physical switch about the reachability of a media access control (MAC) address associated with a device coupled to both the switch and the separate physical switch. ### Claim 7 (depends on 6) The switch of claim 6, wherein the memory further stores instructions which when executed cause the processor to disassociate the device from the virtual switch upon detecting a failure of a link between the device and the separate physical switch. ### Claim 8 (depends on 6) The switch of claim 6, wherein the memory further stores instructions which when executed cause the processor to notify the separate physical switch of a failure via an inter-switch communication channel upon detecting a failure of a link between the device and the switch. ### Claim 9 (depends on 1) The switch of claim 1, wherein the memory further stores instructions which when executed cause the processor to advertise that the virtual switch is associated with both the switch and the separate physical switch, thereby facilitating multi-path routing to or from a device coupled to both switches. ### Claim 10 (depends on 1) The switch of claim 1, wherein the memory further stores instructions which when executed cause the processor to discard a received multicast frame corresponding to a multicast group to which a device coupled to both the switch and the separate physical switch belongs, when: the frame's ingress switch identifier corresponds to the virtual switch identifier; or the frame's ingress switch identifier is different from the virtual switch identifier and a link between the device and the switch is not a primary link. ### Claim 11 (depends on 1) The switch of claim 1, wherein the memory further stores instructions which when executed cause the processor to forward a multicast frame originated from a first local device coupled to the switch to a second local device coupled to both the switch and the separate physical switch, when the second local device is in a multicast group corresponding to the multicast frame. ### Claim 12 A method, comprising: forming a single logical switch which includes one or more separate physical switches, the logical switch having a virtual switch identifier; and marking an ingress-switch field of a frame with the virtual switch identifier. ### Claim 13 (depends on 12) The method of claim 12, further comprising performing a layer-2 routing function without requiring the network topology to be based on a spanning tree topology. ### Claim 14 (depends on 12) The method of claim 12, further comprising performing a layer-2 routing function in accordance with the Transparent Interconnection of Lots of Links (TRILL) protocol. ### Claim 15 (depends on 12) The method of claim 12, further comprising advertising to a neighbor a zero-cost link from the switch to the logical switch. ### Claim 16 (depends on 12) The method of claim 12, further comprising placing the virtual switch identifier in the header of an ingress frame. ### Claim 17 (depends on 12) The method of claim 12, further comprising notifying a separate physical switch about the reachability of a media access control (MAC) address associated with a device coupled to the switch. ### Claim 18 (depends on 17) The method of claim 17, wherein upon detecting a failure of a link between the device and the separate physical switch, the method further comprises disassociating the device from the virtual switch. ### Claim 19 (depends on 17) The method of claim 17, wherein upon detecting a failure of a link between the device and the switch, the method further comprises notifying the separate physical switch of a failure via an inter-switch communication channel. ### Claim 20 (depends on 12) The method of claim 12, further comprising advertising that the virtual switch is associated with both the switch and the separate physical switch, thereby facilitating multi-path routing to or from a device coupled to both switches. ### Claim 21 (depends on 12) The method of claim 12, further comprising discarding a received multicast frame corresponding to a multicast group to which a device coupled to both the switch and the separate physical switch belongs, when: the frame's ingress switch identifier corresponds to the virtual switch identifier; or the frame's ingress switch identifier is different from the virtual switch identifier and a link between the device and the switch is not a primary link. ### Claim 22 (depends on 12) The method of claim 12, further comprising forwarding a multicast frame originated from a first local device coupled to the switch to a second local device coupled to both the switch and the separate physical switch, when the second local device is in a multicast group corresponding to the multicast frame. ### Claim 23 A switch means, comprising: an inter-switch communication means for communicating with a separate physical switch; a management means for operating the switch in conjunction with the separate physical switch as a single logical switch which is assigned a virtual switch identifier; and a frame-marking means for marking an ingress-switch field of a frame with the virtual switch identifier.