(Alpha and Integrity servers) LAN_FLAGS is a bit mask used to
    enable features in the local area networks port drivers and
    support code. The default value for LAN_FLAGS is 0.
    The bit definitions are as follows:
    Bit        Description
    0          The default of zero indicates that ATM devices run in
               SONET mode. If set to 1, this bit indicates ATM devices
               run in SDH mode.
    1          If set, this bit enables a subset of the ATM trace
               and debug messages in the LAN port drivers and support
               code.
    2          If set, this bit enables all ATM trace and debug
               messages in the LAN port drivers and support code.
    3          If set, this bit runs UNI 3.0 over all ATM adapters.
               (Auto-sensing of the ATM UNI version is enabled if both
               bit 3 and bit 4 are off (0).)
    4          If set, this bit runs UNI 3.1 over all ATM adapters.
               (Auto-sensing of the ATM UNI version is enabled if both
               bit 3 and bit 4 are off (0).)
    5          If set, disables auto-negotiation over all Gigabit
               Ethernet Adapters.
    6          If set, enables the use of jumbo frames over all
               Gigabit Ethernet Adapters.
    7          Reserved.
    8          If set, disables the use of flow control over all LAN
               adapters that support flow control.
    9          Reserved.
    10         Reserved.
    11         If set, disables the logging of error log entries by
               LAN drivers.
    12         If set, enables a fast timeout on transmit requests,
               usually between 1 and 1.2 seconds instead of 3 to 4
               seconds, for most LAN drivers.
    13         If set, transmits that are given to the LAN device
               and never completed by the device (transmit timeout
               condition) are completed with error status (SS$_ABORT)
               rather than success status (SS$_NORMAL).
    LAN_FLAGS is a DYNAMIC parameter.