[SNMP4J] How to Remove an SNMP Community String.

[Vivi Zhang]

Frank:

Thank you very much for your help.  As you suggested, the problem is 
around the coexistenceInfo within SnmpCommunityMIB, indeed.

I did set the coexistence provider at the CommandProcessor.  The 
createRow adds a cummunity row entry to coexistenceInfo map.

The statement 
"communityMIB.getSnmpCommunityEntry().removeRow(aRow.getIndex());" 
removes a community row from Community entry table. But this statement 
does not remove the row from coexistenceInfo which is used by 
CommandProcessor to check the security name. 

Currently, I added a statement "comEntryModel.freeRow(aRow);" 
immediately after preivous statement, and this stmt helps.
    private void removeOneCommunity(SnmpCommunityMIB communityMIB, 
MOTableRow aRow)
    {
        MOMutableTableModel comEntryModel = 
(MOMutableTableModel)communityMIB.getSnmpCommunityEntry().getModel();
        communityMIB.getSnmpCommunityEntry().removeRow(aRow.getIndex());
        comEntryModel.freeRow(aRow);
    }

The SnmpCommunityEntryRowFactory.freeRow() is invoked which removes the 
community string from coexistenceInfo.

Is this preferred way to remove a community string? 

Thanks again.

Vivi

Frank Fock wrote:
> Hi Vivi,
>
> I assume that you did not set the coexistence provider
> at the CommandProcessor to your instance of the
> SnmpCommunityMIB class.
>
> The CommandProcessor then uses the SNMPv1/v2c community
> as security name directly without mapping it to a
> security name using the SNMP-COMMUNITY-MIB mapping.
> Since you have an equal security name in your VACM
> configuration, the request goes through.
>
> For further questions read RFC 3414 and 3415.
>
> Regards,
> Frank
>
> Vivi Zhang wrote:
>> Let me resend the email.
>>
>> The previous email content was in an attachment. It did not show up 
>> in SNMP4j email archives.
>>
>> ============================================================================================= 
>>
>>
>> Hi,
>>
>> I would really appreciate any help to find a way to remove an SNMP 
>> community string .
>> I am using SNMP4j 1.9.3c, and SNMP4j agent 1.2.1d.
>>
>> I have no problem to add more community string to a running SNMP 
>> agent. But, when I have not been successfully remove a community string.
>>
>> Following is a section of code which initializes community mib and 
>> other mibs.
>>
>>        vacmMIB = new VacmMIB(new MOServer[] { server });
>>        snmpTargetMIB = new SnmpTargetMIB(dispatcher);
>>        snmpNotificationMIB = new SnmpNotificationMIB();
>>      *  snmpCommunityMIB = new SnmpCommunityMIB(snmpTargetMIB);*
>>        this.getServer().addContext(DEFAULTCONTEXT);
>>        initConfigMIB();
>>        notificationOriginator = new NotificationOriginatorImpl(session,
>>                                                                vacmMIB,
>>                                                                
>> snmpv2MIB.getSysUpTime(),
>>                                                                
>> snmpTargetMIB,
>>                                                                
>> snmpNotificationMIB);
>>        snmpv2MIB.setNotificationOriginator(notificationOriginator);
>>
>> Following is a section of code which add a community string to 
>> community MIB
>>
>>        Variable[] com2sec = new Variable[] {
>>                new OctetString(aCommunity), SECNAMEV1V2,  
>> getContextEngineID(), DEFAULTCONTEXT,
>>                new OctetString(), // transport tag
>>                new Integer32(StorageType.nonVolatile), // storage type
>>                new Integer32(RowStatus.active) // row status
>>        };
>>
>>        MOTableRow row = 
>> communityMIB.getSnmpCommunityEntry().createRow(index,
>>                                                                        
>> com2sec);
>>        communityMIB.getSnmpCommunityEntry().addRow(row);
>>
>> To remove all community strings, I tried following code:
>>   MOMutableTableModel comEntryModel = 
>> (MOMutableTableModel)communityMIB.getSnmpCommunityEntry().getModel();
>>   comEntryModel .clear();
>>
>> After this call, I expect all community rows are gone, and all SNMP 
>> queries should fail.  But this does not happen.
>>
>> I also try to remove an individual community string using API call
>> communityMIB.getSnmpCommunityEntry().removeRow(index); where index is 
>> a valid OID for a community string.
>> In both cases, the row is removed, but the event did not fired since 
>> moTableModelListeners  == null.
>> public synchronized MOTableRow removeRow(OID index) {
>>    *MOTableRow row = (MOTableRow) rows.remove(index);*
>>    if ((row != null) && (moTableModelListeners != null)) {
>>      MOTableModelEvent event =
>>         new MOTableModelEvent(this, MOTableModelEvent.ROW_REMOVED, row);
>>      fireTableModelChanged(event);
>>    }
>>    return row;
>>  }
>>
>> After the calls, I am still able to query the snmp agent with 
>> "removed" community string.
>>
>> Wonder if it is expected behavior.  Or I need config the 
>> TableModelListeners for SnmpCommunityEntry table.
>> Please advise.
>>
>> Vivi
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>