Breakout ports

On 7220 IXR-D3, D5, and H3 systems, the QSFP28 connector ports (ports 1/3-1/33) can operate in breakout mode. Each QSFP28 connector port operating in breakout mode can have four breakout ports configured, each operating at 25G.

To enable breakout ports, you enable breakout mode for an interface and configure breakout ports for the interface. Breakout ports are named using the following format:

ethernet-slot/port/breakout-port

For example, if interface ethernet 1/3 is enabled for breakout mode, its breakout ports are named as follows:

• ethernet 1/3/1

• ethernet 1/3/2

• ethernet 1/3/3

• ethernet 1/3/4

When an interface is operating in breakout mode, it is considered a breakout connector, and not an Ethernet port. Some features that are configurable on an Ethernet port do not apply to a breakout connector. The following parameters cannot be configured on an interface operating as a breakout connector:

• mtu

• loopback-mode

• aggregate-id

• auto-negotiate

• duplex-mode

• flow-control receive

• flow-control transmit

• lacp-port-priority

• port-speed

• standby-signaling

• reload-delay

• hold-time

• storm-control

• vlan-tagging

• subinterface

• lag

• qos

• sflow

• transceiver

When the admin-state parameter for a breakout connector is set to disable, it causes its breakout ports to be shut down. In this case, the output from the info from state command lists the oper-down-reason for the breakout ports as connector-down.

The port-speed setting is not configurable for a breakout port. The speed of the breakout port is determined by the channel-speed setting for the breakout connector.

Note the following when configuring the transceiver parameter for a breakout port:

• The tx-laser setting affects only the individual breakout port. If the installed transceiver supports per-channel disabling of the TX laser then configuring tx-laser = false causes the state of the breakout port to be oper-down.

  If the installed transceiver does not support per-channel disabling of the TX laser, then the state of the breakout port remains oper-up and info from state displays tx-laser=true.

• If ddm-events = true is configured for any breakout port, then the system generates warning logs for temperature and voltage of the overall transceiver/connector.

  If ddm-events = false for any breakout port, the system suppresses warning logs for input-power, output-power, and laser-bias-current for that specific port/laser.

• The configured forward-error-correction algorithm applies only to the individual breakout port.

--{ candidate shared default }--[  ]--
# info interface ethernet-1/3*
    interface ethernet-1/3 {
        admin-state enable
        description "Breakout connector"
        breakout-mode {
            num-channels 4
            channel-speed 25G
            }
        }
    }
    interface ethernet-1/3/1 {
        admin-state enable
        description "Breakout port 1"
        subinterface 1 {
            admin-state enable
            ipv4 {
                address 192.168.12.1/30 {
                }
            }
        }
    }
    interface ethernet-1/3/2 {
        admin-state enable
        description "Breakout port 2"
        subinterface 1 {
            admin-state enable
            ipv4 {
                address 192.168.12.2/30 {
                }
            }
        }
    }
    interface ethernet-1/3/3 {
        admin-state enable
        description "Breakout port 3"
        subinterface 1 {
            admin-state enable
            ipv4 {
                address 192.168.12.3/30 {
                }
            }
        }
    }
    interface ethernet-1/3/4 {
        admin-state enable
        description "Breakout port 4"
        subinterface 1 {
            admin-state enable
            ipv4 {
                address 192.168.12.4/30 {
                }
            }
        }
    }