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Conference 7.286::fddi

Title:FDDI - The Next Generation
Moderator:NETCAD::STEFANI
Created:Thu Apr 27 1989
Last Modified:Thu Jun 05 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:2259
Total number of notes:8590

1045.0. "Rate limiting on DB620?" by CSC32::D_SHAVEY () Mon Aug 02 1993 15:24

    Problem:
    
    MCC V1.3
    DECbridge 620 (with microcode 1.3)
    dec_elan_27 mib is compiled
    
    As per the Release Notes for the DECbridge 500/600 series, microcode
    version 1.3, it states on page 4:
    
    o Rate limiting - Multicast and Broadcast frames forwarded by the
    bridge can  be rate limited.  You can set (enable) the rate limit 
    threshold (in packets per second) using SNMP.  The default rate limit 
    threshold is 400 packets per second.  You can specify rate-limited 
    frames by address or protocol (Enet p-type, DSAP or PID).   Rate-limited 
    frames are counted and read using the appropriate objects in the DEC 
    Vendor MIB.  Rate limiting is disabled when shipped from the factory.
    
    I, and a customer are able to enter in the example A in the release
    notes:
    
    Example A
    ---------
    Configure a DECbridge 500 Series bridge to forward no more than 500
    packets per second having the multicast address 09-00-2b-ff-ff-ff in
    the destination field.
    
    1.Set the rate limit value to 500:
    
    > SNMP SET ebrRateLimit_0 to 500
    
    2.Set status of address 09-00-2b-ff-ff-ff to rateLimit  Note: In
    general,   addresses expressed in hexadecimal are converted to decimal
    when embedding   them in SNMP OIDs:
    
    > SNMP SET ebrTwoPortStatus_9.0.43.255.255.255.0 to 7
    
    3.Enable rate limiting feature:
    
    > SNMP SET ebrRateLimitSwitch_0 to 1
    
    But, when we try to enter in an already known static entry, we get
    an error of:
    
    attribute not available
    
    Also, can the all F's be put in for rate limiting, as I got the
    attribute not available on it also. 
    
    Is it possible to partial wildcard multicast entries?
    
    ie: 09002b*
    
    Thank you
    
    Darrell Shavey
    CSC32::D_SHAVEY
    DTN 592-4712
    
T.RTitleUserPersonal
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1045.1MCC examples of RATE LIMITING not workingGADWAL::WOESTEMEYERWhy??...Why not!!!Wed Aug 04 1993 12:3563
    Having worked with Darrel on this, I thought some examples might be of
    benefit.  I sent mail to an MCC engineering contact on the SNMP side of
    the house.  His reply was that it looked like an agent problem, not an
    MCC problem.  Hope the example helps.
    
    Steve Woestemeyer
    CSC/CS - Network Support Group

Since the release of the DECbridge V1.3 software, rate limiting of multicasts
was supported.  The DEC_elan_v27 mib as required so I loaded it.  From the 
attached MCC log, the ebrmultiportstatus attribute is getable, both via  all
characteristics and seperately.  However, it the multicast address already 
exists in the address list the attribute ebrmultiport status is not
settable.  The returned error is 'attribute not available'.

If an address that is not in the address table is entered, the address is
added to the address list with the correct ebrmultiportstatus. However, it 
cannot be modified.

It would seem to me that if the attribute can be retrieved it should be able 
to be set.  The MIB does allow read-write access to it.

Any ideas on how to modify the ebrmultiportstatus of an existing entry??

-----------------------------------------------------------------------------

show snmp db620-1 dec ema decmibextension elanext ebridge ebrmultiportstatic ebrmultiportstatictable (%xffffffffffff,2) all char
!
!SNMP db620-1 dec ema decMIBextension elanext ebridge ebrMultiPortStatic ebrMultiPortStaticTable (%XFFFFFFFFFFFF,2) 
!AT  3-AUG-1993 07:22:53 Characteristics
!
!Examination of attributes shows:
!                    ebrMultiPortAddress = %XFFFFFFFFFFFF
!                ebrMultiPortReceivePort = 2
!              ebrMultiPortAllowedToGoTo = %XF0
!                    ebrMultiPortPortNum = 0
!                     ebrMultiPortStatus = portMask
!
show snmp db620-1 dec ema decmibextension elanext ebridge ebrmultiportstatic ebrmultiportstatictable (%xffffffffffff,2) ebrmultiportstatus
!
!SNMP db620-1 dec ema decMIBextension elanext ebridge ebrMultiPortStatic ebrMultiPortStaticTable (%XFFFFFFFFFFFF,2) 
!AT  3-AUG-1993 07:23:24 Characteristics
!
!                     ebrMultiPortStatus = portMask
!
set snmp db620-1 dec ema decmibextension elanext ebridge ebrmultiportstatic ebrmultiportstatictable (%xffffffffffff,2) ebrmultiportstatus ratelimit
!
!SNMP db620-1 dec ema decMIBextension elanext ebridge ebrMultiPortStatic ebrMultiPortStaticTable (%XFFFFFFFFFFFF,2) 
!AT  3-AUG-1993 07:24:05 Characteristics
!
!Examination of Attributes Shows
!                     ebrMultiPortStatus = -- Attribute Not Available
!
ex
!%MCC-I-NOPARCMD, ex 
!                 ^
!%MCC-I-SYNTAXERR, Syntax error -- unable to interpret remainder of line 
!%MCC-W-VERBAMBIG, verb EX is ambiguous; enter more characters
!
!
exit
!
                                                                        
1045.2Maybe problem with broadcastQUIVER::WALTERFri Aug 13 1993 18:4113
    I wasn't able to do SNMP sets or gets using our version of MCC, so I 
    used a PC-based program. I had no problem setting a multicast address
    to various ebrMultiPortStatus values, but I got a GenError when trying
    to set the broadcast address (FF-FF-FF-FF-FF-FF) to RateLimit. The
    broadcast address is a special address to the bridge software, and gets
    treated differently than other multicast addresses. I mentioned this 
    problem to the support engineer for the bridge.
    
    But I can't explain why you are having problems with other multicast
    addresses. Can you enter a log file of the problem?
    
    Dave