DELL PowerConnect - What does "iscsi enable" do?

From DELL's "EqualLogic iSCSI Optimization for Dell PowerConnect Switches" whitepaper...


After enabling iSCSI, the following procedures occur automatically:

  • Jumbo Frames are enabled on all switch ports. Jumbo Frames enable transporting data in fewer
    frames to ensure less overhead, lower processing time, and fewer interrupts. By default, Jumbo
    Frames are disabled on all PowerConnect switches. To enable Jumbo Frames manually on a
    PowerConnect switch, please refer to Appendix A.

    The host/server has to be configured for Jumbo Frames manually. Jumbo Frames may
    not necessarily improve performance if packets are smaller than 1500 bytes.


  • Spanning-Tree Port-Fast (STPF) is automatically enabled ONLY on the switch interfaces that are
    connected to Dell EQL array to allow fast connection to the EQL array. This is a port specific
    feature that happens only on the switch ports that receive active EQL LLDP messages. By
    removing the connection, the STPF is still enabled on the port unless it gets disabled manually. To
    configure a switch port, manually, to support Spanning-Tree port-fast, please refer to Appendix A.

    MTU 9216 is enabled on all ports and port channels when “iscsi enable” command is
    executed.


  • Unicast Storm Control (USC) is automatically disabled ONLY on the switch interfaces that are
    connected to Dell EQL array. This is a port specific feature that happens only on the switch ports
    that receive an active EQL appearance LLDP messages. By removing the connection, USC is still
    disabled on the port unless it gets enabled manually. To manually disable Unicast Storm Control,
    please refer to Appendix A.

    Unicast Storm Control is globally disabled on all Dell PowerConnect switch ports. The
    “iscsi enable” command ensures that a user has not accidentally enabled this setting.


  • Flow Control enables lower speed switches to communicate with higher speed switches by
    requesting that the higher speed switch refrains from sending packets. Transmissions are
    temporarily halted to prevent buffer overflows. Flow control is globally enabled on all Dell
    PowerConnect switches with firmware release 3.2.0.7 and higher. The “iscsi enable” command
    will automatically enable Flow Control on all switch ports regardless of the firmware version. To
    manually enable Flow Control on a switch, please refer to Appendix A.

    The host/server has to be configured for Flow Control manually.