N-node virtual link trunking (VLT) systems control plane

Patent metadata

Field	Value
Publication number	US-9264347-B2
Application number	US-201314142215-A
Country	US
Kind code	B2
Filing date	Dec 27, 2013
Priority date	Dec 27, 2013
Publication date	Feb 16, 2016
Grant date	Feb 16, 2016

Abstract

Aspects of the present invention include an 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 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 virtual link trunking (VLT) link aggregation groups (LAGs), each of the one or more VLT 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 information handling system nodes in an n-node virtual link trunking (VLT) system, the n-node VLT system comprising a plurality of information handling system nodes;
a fabric manager component that communicatively interfaces with fabric manager components of other information handling system nodes in the n-node VLT system to establish and maintain a consistent representation of the topology of the n-node VLT system with the other information handling system nodes in the n-node VLT system, the consistent representation comprising one or more tables that are use common identifiers for VLT LAGs across the information handling system nodes in the n-node VLT system;
a VLT/inter-node-link (INL) manager component, communicatively coupled to the fabric manager of the information handling system node and communicatively coupled to one or more node-level components of the information handling system node, that obtains information for the fabric manager from the one or more node-level components of the information handling system node; and
a data processing component that facilitates receiving data from and sending data to at least some of the plurality of I/O ports and the plurality of inter-node-link (INL) ports.

2. The information handling system node of claim 1 wherein the fabric manager component communicatively interfaces with fabric manager components of other information handling system nodes in the n-node VLT system to establish and maintain a consistent representation of the topology of the n-node VLT system with other information handling system nodes in the n-node VLT system by establishing and maintaining the one or more tables comprising:
a virtual link trunking (VLT) membership list that comprises a listing of which information handling system nodes in the n-node VLT system participate in the one or more VLT LAGs;
an assigned node list that comprises an assigned node for each information handling system node that may receive ingress traffic on the information handling system node that is destined for a VLT LAG that does not have a link on that information handling system node but does have a link or links on one or more of the other information handling system nodes in the n-node VLT system, the assigned node having a link for the VLT LAG;
a VLT-to-INL list that, for an information handling system node, maps a VLT LAG to an inter-node link (INL) based upon the assigned node for the information handling system node; and
an n-node VLT egress mask list that comprises, for each assigned node assignment, a mapping of allowed VLT LAG egress for data ingressing on a specific INL between information handling system nodes in the n-node VLT system.

3. The information handling system node of claim 1 wherein the one or more tables further comprise a Layer 2/Layer 3 (L2/L3) unicast table and the fabric manager component updates one or more table entries in the Layer 2/Layer 3 (L2/L3) unicast table for the information handling system node and interfaces with the fabric manager components of the other information handling system nodes of the n-node VLT system to synchronize the updated one or more table entries.

4. The information handling system node of claim 3 wherein the fabric manager component, responsive to receiving a synchronization message from another information handling system node, checks whether VLT-to-INL conversion is required based on its VLT LAG membership.

5. The information handling system node of claim 1 wherein the one or more tables further comprise a Layer 2 (L2) multicast table and the fabric manager component updates one or more table entries in the Layer 2 (L2) multicast table for the information handling system node and interfaces with the fabric manager components of the other information handling system nodes of the n-node VLT system to synchronize the updated one or more table entries.

6. The information handling system node of claim 5 wherein the fabric manager component, responsive to receiving a synchronization message from another information handling system node, checks if VLT-to-INL conversion is required based on its VLT LAG membership.

7. The information handling system node of claim 2 wherein, responsive to a topology change being detected in the n-node VLT system, the fabric manager component acts as a topology-change-owner node and takes responsibility for determining one or more table entries which require ownership change and sends messages to those information handling system nodes in the n-node VLT system to assume ownership for certain ones of such table entries.

8. The information handling system node of claim 1 wherein the fabric manager component pre-computes updates in preparation for potential failure conditions including inter-node link (INL) failure, information handling system node failure, or both.

9. The information handling system node of claim 7 wherein the fabric manager component pre-computes updates in preparation for potential failure conditions in conjunction with one or more fabric manager components of one or more other information handling system nodes in the n-node VLT system.

10. The information handling system node of claim 7 wherein the fabric manager component sends a status check message to one or more fabric manager components of one or more other information handling system nodes in the n-node VLT system to detect INL failure, information handling system node failure, or both.

11. The information handling system node of claim 1 wherein the plurality of inter-node-link ports are configured such that the information handling system node is in a full mesh topology with the one or more information handling system nodes of the n-node VLT system.

12. A n-node Virtual Link Trunking (VLT) system comprising:
a plurality of nodes communicatively coupled via inter-node port links (INLs) to facilitate communications with other nodes from the plurality of nodes in the n-node VLT system, each node comprising:
a fabric manager component that communicatively interfaces with fabric manager components of other nodes in the n-node VLT system to establish and maintain a consistent representation of the topology of the n-node VLT system with other nodes in the n-node VLT system by using one or more common fabric-level identifiers;
a VLT/INL manager component, communicatively coupled to the fabric manager of the node and communicatively coupled to one or more components of the node, that obtains information for the fabric manager from the one or more components of the node; and
a data processing component that facilitates receiving data from and sending data to at least some of the plurality of I/O ports and the plurality of inter-node-link (INL) ports; and
at least some of the plurality of nodes communicatively coupled via one or more input/output (I/O) ports to at least one client device configured with a link aggregation group (LAG).

13. The n-node VLT system of claim 12 wherein the plurality of nodes are communicatively coupled to each other in a full mesh topology.

14. The n-node VLT system of claim 12 wherein the fabric manager component

Assignees

• Dell Products Lp

Inventors

• Anumala Mohnish
• Pillai Jeyasubramanian Irungola

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

• H04L12/4675

  Dynamic sharing of VLAN information amongst network nodes (configuration of the network or of network elements H04L41/08) · CPC title

• H04L49/70

  Virtual switches · CPC title