Implementation notes for OpenFlow groups in hardware

  • Groups are not supported in hardware when switch is running in v1 mode.

  • Special ports OFPP_ALL, OFPP_NORMAL, OFPP_TABLE, OFPP_IN_PORT, OFPP_LOCAL and OFPP_CONTROLLER are not supported in OpenFlow groups in hardware.

  • Tunnels cannot be part of OpenFlow ALL group.

  • Rules in OpenFlow software tables can refer to Groups in software or hardware.

  • Rules in OpenFlow hardware tables cannot refer to groups in software.

  • On custom pipeline instances, groups in hardware have counters subject to the availability of the counters.

  • If the group is in software, it can be referenced only from a software table.

  • Rules in hardware tables with group action must not have a goto instruction associated with it.

  • Group Modifications:

    • Modification of a group in hardware that leads to having no Ports, is not allowed.

    • If the resultant modification can no longer be accommodated in H/W, group modification requests for Groups in H/W are rejected.

  • In custom mode, the groups are always in hardware. Attempts to add groups with actions other than output ports are rejected.

  • The number of OpenFlow groups that can be created on an OpenFlow instance is 1024.