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OFSW management port requirements

Sam Ribeiro edited this page Jun 28, 2019 · 3 revisions

1. Motivation

Establish the operational user stories for utilizing management ports in the OpenFlow switch. Articulate the requirements that serve to fulfill them.

2. User stories

2.1 One IP per OpenFlow switch

The OpenFlow controller must handle one, and only one IPv4 per OpenFlow switch. This assures simplicity for programming and observing the OpenFlow switch.

2.2 Two management ports per OpenFlow Switch

The OpenFlow switch must have two management ports. This allows redundant physical connectivity for protecting against port, cable, direct upstream port or network device failure.

2.3 Stable IP connectivity through physical failovers

IP connectivity to the OpenFlow switch management address must remain stable, through forward transitions events between the two management ports. This assures that the control plane of the OpenFlow switch remains stable through a physical connectivity issue adjacent to any of the two management ports.

2.4 No special configuration for upstream ports

The upstream ports where the OpenFlow management ports connect to, must not require any special configuration besside ordinary host port configuration. This assures simplicity in the upstream network devices configuration.

2.5 Support methods for automated bootstrapping

The OpenFlow switch must be able to acquire IP configuration information using DHCP on the management ports. The MAC address of the management ports must also be known. This assures the OpenFlow switch can be provisioned automatically upon installation.

2.6 Management ports must allow copper or fiber connection

OpenFlow switches must allow management ports connecting using optic fiber media, as well as copper cables. This assures management plane connectivity across longer distances.

3. Premise

It is assumed that at factory defaults, some OpenFlow switches have a single management port with its associated network stack. Other OpenFlow switches have two management ports with individual independent network stacks. These premises, together with the user stories, shape the requirements of the next section.

3.1 Requirements

The user stories state the use of one IP address per OpenFlow switch. In addition they require two ports for the management plane, and basic host-port configuration in the network devices upstream. A bootstrapping mechanism must be available for provisioning, and different connectivity media must be supported. The following requirements fulfill these user stories.

3.2 Two multiple-media management ports

The OpenFlow switch has two management physical ports, supporting 2 different connectivity media each, copper and fiber.

3.3 Externally visible MAC addresses

The MAC addresses of the management ports must be externally individually stamped in the OpenFlow switch chassis via a barcode or QR code. Using UPC-A and UPC-E encoding for barcode and ISO/IEC 18004:2015 for QRcodes.

3.4 DHCP client enabled by default

The management ports must have DHCP client enabled when at factory default, or when a factory reset is performed.

3.5 Management port bonding stack

The two management ports must be allowed to be bonded together in Active-Backup. Their expected behaviour is:

  • At any given time, one port is Active, the other is Backup;
  • Either ports accepts ingress packets;
  • When the carrier in the Active port is up, only the Active egreesses sent packets;
  • When the carrier in the Active port is down, the Backup egresses sent packets;
  • Whenever packet egress changes between ports, gratuitous ARPs must be sent;

When bonding the two management ports:

  • The MAC address of the lowest numbered management port is used;
  • The lowest numbered management port takes the Active role;

When bonding between a management port and a data plane port, the management port is considered the lowest numbered port.