Conference netcad::hub_mgnt

519.0. "Summary: 90 Module Mgmt in 900 Hub" by QUIVER::SLAWRENCE () Wed Nov 24 1993 12:24

    This note summarizes the differences in management capability of
    DEChub 90 modules released prior to the release of DEChub 900
    MultiSwitch when used in a 900.

    Other differences may be described by replies to this note; if you
    have questions or comments about these issues PLEASE START A NEW
    NOTE (write) rather than adding a reply here so that this thread
    is more useful as a reference.

DECbridge 90 (both flavors), DECserver 90L, DECserver 90L+:

    Are _NOT_ managed by the DEChub 900 Hub Management Module; they
    require a DECagent 90 somewhere on the network to be managable.
    See the HUBwatch Installation Guide for how to configure them.

    The reason for this is that they are managed by the DECagent by
    translating the SNMP into either RBMS (for the bridge) or MOP
    Console (for the DECservers).  The translated commands are sent to
    the device via the Ethernet interface; since the 900 hub manager
    does not have and Ethernet interface of its own it can't manage
    these modules (they don't respond to commands on the management
    channel). 

90 Repeaters:

    Are managable in the 900 using the Hub Management Module.  The one
    restriction is that the V2.X hub manager firmware does not
    maintain the MIB used to provide the HUBwatch 'Find Address'
    function (which allows you to specify an Ethernet address and
    tells you which repeater port it is on).
    
    The 'Find Address' function was performed primarily by the
    DECbridge using a mechanism that takes advantage of its forwarding
    database to tell it what addresses to ask the repeaters about (it
    can ask, in effect, `Who has address XXX?').

    This feature is planned for the V3.X hub manager firmware; it will
    be implemented slightly differently internally and may take longer
    to build up the required database because the hub manager does not
    have the forwarding database the bridge had.  The hub manager will
    poll to see the 'last address seen' on each port and build up the
    database itself.  This will mean that:

        o Queries made soon after hub powerup may fail even though the
          station is present, especially on ports with multiple stations
          where one or more are much less frequent senders than others.

        o If a station is move the answer may be incorrect for a while.