N-node virtual link trunking (vlt) supporting arbitrary topologies

Patent metadata

Field	Value
Publication number	US-2016234100-A1
Application number	US-201615132060-A
Country	US
Kind code	A1
Filing date	Apr 18, 2016
Priority date	Dec 27, 2013
Publication date	Aug 11, 2016
Grant date	—

Abstract

Aspects of the present invention include an arbitrary N-Node virtual link trunking (VLT) system comprising a set of N nodes collectively provide a logical fabric-level view that is consistent across the set of N nodes. Embodiments of the arbitrary N-Node VLT system comprise a control plane mechanism to provide Layer 2 multipathing between access network devices (switches or servers) and the core network. The N-Node VLT system provides a loop-free topology with active-active load-sharing of uplinks from access to the core. Accordingly, the N-Node VLT system eliminates the disadvantage of Spanning Tree Protocol (STP) (active-standby links) by allowing link aggregation group (LAG) terminations on multiple separate distribution or core switches and also supporting a loop-free topology. Additional benefits of an N-Node VLT system include, but are not limited to, higher resiliency, improved link utilization, and improved manageability of the network.

First claim

What is claimed is:

1 . An information handling system node comprising:
a plurality of input/output (I/O) ports, at least a portion of which facilitate communications with one or more client devices and are configurable to be part of one or more arbitrary topology link aggregation groups (LAGs), each of the one or more LAGs including the information handling system node and at least one of the one or more client devices; a plurality of inter-node-link (INL) ports, at least a portion of which facilitate communications with one or more of peer information handling system nodes in an arbitrary n-node system, which comprises the information handling system node and a plurality of information handling system nodes; a data processing component that processes data traffic, and receives data from and sends data to at least some of the plurality of I/O ports and at least some of the plurality of INL ports; and a designated forwarder module that selects an information handling system node as a designated forwarder for a virtual local area network (VLAN) and the designated forwarder load balances the data traffic.

2 . The information handling system node of claim 1 further comprising a discovery protocol that discovers a connected system over the INL port.

3 . The information handling system node of claim 1 wherein the designated forwarder is selected based on a priority and a node address.

4 . The information handling system node of claim 1 wherein the designated forwarder is selected based on bandwidth of a port channel.

5 . The information handling system node of claim 1 further comprising a media access control (MAC) address synchronization module that synchronizes a MAC address known to the information handling system node by pointing the MAC address to the plurality of information handing system nodes on the LAG.

6 . The information handling system node of claim 1 wherein the INL ports are configured to be a member of each virtual local area network (VLAN) defined in the n-node system.

7 . The information handling system node of claim 1 wherein the designated forwarder module selects a backup forwarder that takes over for the designated forwarder in the event the designated forwarder is unable to act as the designated forwarder.

8 . The information handling system node of claim 1 further comprising an external tunnel extender tag used during Access Control List (ACL) lookup.

9 . A n-node system comprising:
a plurality of node devices communicatively coupled to each other via inter-node link (INL) ports to facilitate communications with one or more of the other node devices from the plurality of node devices in the n-node system, wherein the communications are facilitated using a designated forwarder node device selected from the plurality of node devices; and at least some of the plurality of node devices communicatively coupled via one or more input/output (I/O) ports to a client device configured with a link aggregation group (LAG), the plurality of node devices of the n-node system associating a common identifier with each of the ports of the at least some of the plurality of node devices that participate in the LAG and using a designated forwarder node device to load balance communications.

10 . The n-node system of claim 9 wherein the plurality of node devices are communicatively coupled to each other via inter-node link (INL) port in an arbitrary topology.

11 . The n-node system of claim 9 wherein the communications are facilitated using a discovery protocol.

12 . The n-node system of claim 9 wherein the communications are facilitated using a media access control (MAC) address learning on at least one of the plurality of node devices indicating a node device directly communicatively coupled to the at least one of the plurality of node devices.

13 . The n-node system of claim 9 wherein a backup forwarder is selected that takes over for the designated forwarder in the event the designated forwarder is unable to act as the designated forwarder.

14 . The n-node system of claim 9 wherein the designated forwarder is selected based on bandwidth of a port channel.

15 . The n-node system of claim 9 wherein the designated forwarder is selected based on a priority and a node address.

16 . The n-node system of claim 15 wherein the INL ports are configured to be a member of each virtual local area network (VLAN) defined in the n-node system.

17 . The n-node system of claim 9 wherein the n-node system is configured to provide load balancing across the N nodes.

18 . A method of providing communications using an n-node system comprising a plurality of nodes communicatively coupled to each other via inter-node port links (INLs), the method comprising:
forming an arbitrary topology between the nodes of the n-node system; at a fabric level:
for each link aggregation group (LAG) spanning a plurality of nodes in the n-node system, selecting a designated forwarder node per virtual local area network (VLAN) from the plurality of nodes; and
operating the link aggregation group or groups across the n-node system using the designated forwarder to transmit traffic out of a port.

19 . The method of claim 18 further comprising selecting a backup designated forwarder to transmit traffic in the event the designated forwarder does not transmit the traffic.

20 . The method of claim 18 wherein the designated forwarder is selected based on a priority and a node address.

Assignees

• Dell Products Lp
• Dell Products Lp

Inventors

• Pathangi Narasimhan Janardhanan
• Sundaram Shivakumar
• Natarajan Avinash

Classifications

• H04L45/02

  Topology update or discovery · CPC title

• H04L45/48

  Routing tree calculation · CPC title

• H04L41/122

  of virtualised topologies, e.g. software-defined networks [SDN] or network function virtualisation [NFV] · CPC title

• H04L45/245 Primary

  Link aggregation, e.g. trunking · CPC title

• H04L69/324

  in the data link layer [OSI layer 2], e.g. HDLC · CPC title