@CLS@@0F@
    Examples of how to use the GIGAswitch/FDDI system OBM MIB viewer

    We'll look at the number of topology changes.  If you haven't
used the OBM MIB viewer before, when it asks for an Object
Identifier, you can either type in the numeric OID, or the name of
the object (the OID is case sensitive, so be certain that you have
the proper case).

    Note that you need to specify the instance for MIB objects.  If
you are not specifying something like a table indexed by port number,
you generally need to specify the zero'th instance:

 Mib-Viewer Menu -
      1 GET
      2 GETNEXT
      3 Return to Main menu
   Choice: 1

 Object Identifier: dot1dStpTopChanges.0
     Object ID: dot1dStpTopChanges.0
     Value: ea 2 0 0
 Object Identifier:

    In this case, the value returned for this counter is in reverse
byte order, so it needs to be converted to decimal.  For example, on
an OpenVMS system:

$ x = %x000002ea
$ show symbol x
  X = 746   Hex = 000002EA  Octal = 00000001352

    ..the value in decimal is 746 - we'll confirm this with DECmcc:

MCC> show snmp giga1 dot1dbridge dot1dStp dot1dStpTopChanges

SNMP giga1 dot1dBridge dot1dStp
AT 10-AUG-1994 11:06:25 Counters

                     dot1dStpTopChanges = 746
MCC>


    Specifying indices is pretty obscure if you haven't done it
before, so here are some examples of SNMP GETs for indexed objects:



    ifInDiscards - indexed by port number:

 Object Identifier: ifInDiscards.1         - for port 1
     Object ID: ifInDiscards.1
     Value: b2 10 0 0
 Object Identifier:

$ x = %x10b2
$ sho sym x
  X = 4274   Hex = 000010B2  Octal = 00000010262




    snmpFddiPORTPCType - indexed by the Port/PMD

Object Identifier: snmpFddiPORTPCType.1.1         Port 1 - first PMD
     Object ID: snmpFddiPORTPCType.1.1
     Value: 1                                      = a
 Object Identifier: snmpFddiPORTPCType.1.2        Port 1 - second PMD
     Object ID: snmpFddiPORTPCType.1.2
     Value: 2                                      = b



    ebrNportSANameSA - indexed by filter name (ASCII string)

      ...in this case, the characters in the string must be converted
to the decimal value for the ASCII character separated by periods, 
I.E. for "Filter" - note case is important...
    F = 70
    i = 105
    l = 108
    t = 116
    e = 101
    r = 114

  so, the instance would be 70.105.108.116.101.114

Object Identifier: ebrNportSANameSA.70.105.108.116.101.114
     Object ID: ebrNportSANameSA.70.105.108.116.101.114
     Value: ba d0 0 0 0 0
 Object Identifier:



    dot1dTpFdbPort - indexed by the MAC address.  This gets pretty
wierd: You have to convert the MAC address into a dotted decimal
representation. MAC addresses are typed out by many products in the
form:

aa-00-04-00-be-10   becomes:  aa 0 4 0 be 10 (removing leading zeroes)

..now convert those hex numbers into decimal numbers.  

aa 0 4 0 be 10      becomes:  170 0 4 0 190 16


    The field is 7 bits wide, so if the result doesn't fit in 7 bits,
then you need to overflow into another dotted decimal field, I.E.

aa = 170 (decimal) this doesn't fit into 7 bits, so it overflows
thusly:

    170-128 = 42  ..so   170 is represented as 129.42

be = 190 (decimal)     190-128 = 62    ergo  129.62


   put them all together and you get:  129.42.0.4.0.129.62.16

...so for MAC address AA-00-04-00-BE-10:

 Object Identifier: dot1dTpFdbPort.129.42.0.4.0.129.62.16
     Object ID: dot1dTpFdbPort.129.42.0.4.0.129.62.16
     Value: 1                                  ..it lives on port 1