# US 12,113,707 B2 · MAC-based redistribution in multi-area networks

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- Number: US 12,113,707 B2
- Document ID: US12113707B2
- Status: Granted
- Kind: B2
- Application number: 18/446,519
- Filed: 2023-08-09
- Published: 2023-11-30
- Granted: 2024-10-08
- Earliest claimed: 2021-02-05
- Assignees: Extreme Networks, Inc.
- Applicants: Extreme Networks, Inc.
- Inventors: Lava K. Lavu; Constantin Barcaru
- Web page: https://patentgrep.com/patent/US12113707B2

## CPC

- H04L 45/04: {Interdomain routing, e.g. hierarchical routing}
- H04L 45/566: {Routing instructions carried by the data packet, e.g. active networks}
- H04L 12/18: for broadcast or conference {, e.g. multicast}
- H04L 12/4633: {Interconnection of networks using encapsulation techniques, e.g. tunneling}
- H04L 12/4641: {Virtual LANs, VLANs, e.g. virtual private networks [VPN] (LAN interconnection over a bridge based backbone H04L12/462; encapsulation techniques H04L12/4633; routing of packets H04L45/00; packet switches H04L49/00; virtual private networks for security H04L63/0272)}
- H04L 41/12: Discovery or management of network topologies
- H04L 45/34: {Source routing}
- H04L 45/44: Distributed routing
- H04L 45/66: {Layer 2 routing, e.g. in Ethernet based MAN's}
- H04L 2101/622: Layer-2 addresses, e.g. medium access control [MAC] addresses
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)

## Abstract

Provided herein are systems and methods for providing a MAC-based redistribution policy between networks in a multi-area network. A network can have a boundary node that communicates to neighboring networks. Boundary nodes can receive policy updates that identify which services are redistributable across network boundaries. Boundary nodes can receive a packet for a service, translate the packet's encapsulation, and forward the packet across the boundary towards a destination node. Boundary nodes can forward the packet such that it originates in the second network from a virtual node.

## Claims

### Claim 1

A method for synchronizing addresses between multiple forwarding nodes in a multi-area network, the method comprising:
receiving, at a boundary node in a first network of the multi-area network, a media access control (MAC) learn Type-Length-Value (TLV) from a node in a second network, wherein the boundary node is on a boundary between the first network and a third network of the multi-area network, wherein the MAC learn TLV comprises a customer MAC address and a backbone MAC destination address (BMAC-DA), and wherein the customer MAC address is absent from the node;
adding, by the boundary node, the customer MAC address pointing to the BMAC-DA to a MAC table for the boundary node; and
updating, by a control plane and other boundary nodes on the boundary, a respective MAC table for each of the other boundary nodes based on the MAC table.

### Claim 2 (depends on 1)

The method of claim 1, wherein updating each of the respective MAC tables based on the MAC table comprises:
creating, in the control plane, an updated MAC learn TLV based on the MAC table;
sending, by the control plane, the updated MAC learn TLV to each of the other boundary nodes; and
updating, in each of the other boundary nodes, the respective MAC table based on the updated MAC learn TLV.

### Claim 3 (depends on 1)

The method of claim 1, further comprising:
in response to the customer MAC address added to the MAC table being present for longer than a predetermined time period:
removing, in the boundary node, the customer MAC address from the MAC table; and
updating, by the control plane, the respective MAC table for each of the other boundary nodes based on the MAC table.

### Claim 4 (depends on 3)

The method of claim 3, further comprising:
in response to removing the customer MAC address, determining, in the boundary node, whether a second MAC learn TLV is stored in a TLV list, wherein the second MAC learn TLV comprises the customer MAC address and a second BMAC-DA.

### Claim 5 (depends on 4)

The method of claim 4, further comprising:
in response to determining that the second MAC learn TLV is stored in the TLV list:
promoting, by the boundary node, the customer MAC address pointing to the second BMAC-DA to the MAC table; and
updating, by the control plane, the respective MAC table for each of the other boundary nodes based on the MAC table.

### Claim 6 (depends on 1)

The method of claim 1, further comprising storing, by the boundary node, the MAC learn TLV in a TLV list.

### Claim 7 (depends on 1)

The method of claim 1, further comprising updating, by the boundary node, for each interior node in the first network, a different respective MAC table based on the MAC table of the boundary node.

### Claim 8

A boundary node for synchronizing addresses between multiple forwarding nodes in a multi-area network, the boundary node comprising:
a memory; and
a processor communicatively coupled to the memory and configured to:
receive, at the boundary node in a first network of the multi-area network, a media access control (MAC) learn Type-Length-Value (TLV) from a node in a second network, wherein the boundary node is on a boundary between the first network and a third network of the multi-area network, wherein the MAC learn TLV comprises a customer MAC address and a backbone MAC destination address (BMAC-DA), and wherein the customer MAC address is absent from the node;
add the customer MAC address pointing to the BMAC-DA to a MAC table for the boundary node; and
update, using a control plane and other boundary nodes on the boundary, a respective MAC table for each of the other boundary nodes based on the MAC table.

### Claim 9 (depends on 8)

The boundary node of claim 8, wherein to update each of the respective MAC tables based on the MAC table, the processor is configured to:
create, in the control plane, an updated MAC learn TLV based on the MAC table;
send, by the control plane, the updated MAC learn TLV to each of the other boundary nodes; and
update, in each of the other boundary nodes, the respective MAC table based on the updated MAC learn TLV.

### Claim 10 (depends on 8)

The boundary node of claim 8, wherein the processor is further configured to:
in response to the customer MAC address added to the MAC table being present for longer than a predetermined time period:
remove the customer MAC address from the MAC table; and
update, using the control plane, the respective MAC table for each of the other boundary nodes based on the MAC table.

### Claim 11 (depends on 10)

The boundary node of claim 10, wherein the processor is further configured to:
in response to removing the customer MAC address, determine whether a second MAC learn TLV is stored in a TLV list, wherein the second MAC learn TLV comprises the customer MAC address and a second BMAC-DA.

### Claim 12 (depends on 11)

The boundary node of claim 11, wherein the processor is further configured to:
in response to determining that the second MAC learn TLV is stored in the TLV list:
promote the customer MAC address pointing to the second BMAC-DA to the MAC table; and
update, using the control plane, the respective MAC table for each of the other boundary nodes based on the MAC table.

### Claim 13 (depends on 8)

The boundary node of claim 8, wherein the processor is further configured to store the MAC learn TLV in a TLV list.

### Claim 14 (depends on 8)

The boundary node of claim 8, wherein the processor is further configured to update, for each interior node in the first network, a different respective MAC table based on the MAC table of the boundary node.

### Claim 15

A non-transitory computer readable storage medium having computer readable code thereon, the non-transitory computer readable storage medium including instructions configured to cause a computer system to perform operations by a boundary node for synchronizing addresses between multiple forwarding nodes in a multi-area network, the operations comprising:
receiving, at the boundary node in a first network of the multi-area network, a media access control (MAC) learn Type-Length-Value (TLV) from a node in a second network, wherein the boundary node is on a boundary between the first network and a third network of the multi-area network, wherein the MAC learn TLV comprises a customer MAC address and a backbone MAC destination address (BMAC-DA), and wherein the customer MAC address is absent from the node;
adding, by the boundary node, the customer MAC address pointing to the BMAC-DA to a MAC table for the boundary node; and
updating, by a control plane and other boundary nodes on the boundary, a respective MAC table for each of the other boundary nodes based on the MAC table.

### Claim 16 (depends on 15)

The non-transitory computer readable storage medium of claim 15, wherein updating each of the respective MAC tables based on the MAC table comprises:
creating, in the control plane, an updated MAC learn TLV based on the MAC table;
sending, by the control plane, the updated MAC learn TLV to each of the other boundary nodes; and
updating, in each of the other boundary nodes, the respective MAC table based on the updated MAC learn TLV.

### Claim 17 (depends on 15)

The non-transitory computer readable storage medium of claim 15, the operations further comprising:
in response to the customer MAC address added to the MAC table being present for longer than a predetermined time period:
removing, in the boundary node, the customer MAC address from the MAC table; and
updating, by the control plane, the respective MAC table for each of the other boundary nodes based on the MAC table.

### Claim 18 (depends on 17)

The non-transitory computer readable storage medium of claim 17, the operations further comprising:
in response to removing the customer MAC address, determining, in the boundary node, whether a second MAC learn TLV is stored in a TLV list, wherein the second MAC learn TLV comprises the customer MAC address and a second BMAC-DA.

### Claim 19 (depends on 18)

The non-transitory computer readable storage medium of claim 18, the operations further comprising:
in response to determining that the second MAC learn TLV is stored in the TLV list:
promoting, by the boundary node, the customer MAC address pointing to the second BMAC-DA to the MAC table; and
updating, by the control plane, the respective MAC table for each of the other boundary nodes based on the MAC table.

### Claim 20 (depends on 15)

The non-transitory computer readable storage medium of claim 15, the operations further comprising storing, by the boundary node, the MAC learn TLV in a TLV list.