For an octal port such as a QSFPDD or OSFP, this feature renumbers the ports on a system to have 4 configurable

For a pair of QSFP100 ports grouped together on a gearbox, it is possible to enable a 10G or 25G link on the first primary port while maintaining the usage of the secondary port at any speed. For two QSFP100 ports on a gearbox, the primary port allows for breakout speeds 4x10G and 4x25G, while the secondary does not. The configuration of the primary port determines whether the secondary port can be used since in a full breakout mode such as 4x10G the secondary port is forced inactive.