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Re: Retrieval of a single row from read-only Table

From: <forumdesai@ta...> - 2009-11-10 09:46

The table is indexed by the MAC address and it is a read only table. So 
I have added Private Mib parameter that takes the Key value
    from the user as a set parameter. I am able to retrieve the details 
of all the parameters for that key value and storing it into a structure.
    I want to display these values but when I run the for loop for 
requests, the request has the parameter details of the private MIB.
    Is there anyway I display the single row for the SET request?

       Ex.
       Table X is read only table
       It is indexed by MAC address.
   
       Table Y = private Mib
       "y" is Table Y parameter that is settable
       "y" fetches the MAC address from the user and fetches the data 
for that MAC address through Get a single row and
        stores it in a "x" structure (this structure has all parameters 
of Table X).
      
       I want to display the Table X one row based on whatever I have 
stored in "y" structure.
      
    How to retrieve these in single row format??
      
      
     

Dave Shield wrote:
> 2009/11/10 forumdesai@... <forumdesai@...>:
>   
>>  But my requirement is I know the key values but I am not aware where
>> (as in which row ) it will appear.
>>   It is something like MAC address of the CPEs connected to my system.
>>     
>
> Retrieving information from a MIB table is critically dependent on the
> design of that table.   And in particular, the indexing of that table.
>
> If you need to be able to retrieve information for a particular MAC address,
> then you need a MIB table that is indexed by MAC address.   SNMP can
> only work with the indexes that have been defined.   It can't handle
> generating indexes for other columns on thefly.
>    (It's the "simple" network management protocol, remember!)
>
> If you need anything else, then you'd have to walk the MAC address
> column, and look for the desired value.   Then you could extract the
> index value for that instance, and use a GET request to retrieve the
> rest of the row.   There's no real alternative.
>
>
> Now all of this could be wrapped within a library routine, so the details
> could be hidden from the end coder (e.g. see the AnyData::SNMP
> perl module, which makes SNMP queries look like SQL).
> But fundamentally, that's what would be needed.
>
> Dave
>
>

Thread View

Thread	Author	Date
Retrieval of a single row from read-only Table	<forumdesai@ta...>

Re: Retrieval of a single row from read-only Table

From: Dave Shield <D.Shield@li...> - 2009-11-10 08:52

2009/11/10 forumdesai@... <forumdesai@...>:
>       I have a standard Mib. It has a read only Table which has a
> primary key. I am able to retrieve values for the table view.
>         But I want to retrieve only a single row from whole table view.
> I have the key details for that specific row.


If you run 'snmpwalk' on the table, you'll see that the entries
have the form:

     MIB::object1.index1 =  someValue
     MIB::object1.index2 =  someValue
          :
     MIB::object1.indexN =  someValue
     MIB::object2.index1 =  someValue
          :
     MIB::objectM.indexN =  someValue


If you run the command

     snmpget ....   MIB::object1.indexX    MIB::object2.indexX    ...
MIB::objectM.indexX

this will return all of the specified objects  - i.e. one row of the table.
If you don't actually need all of these column values, just specify the
ones you are interested in.

Dave

Re: Retrieval of a single row from read-only Table

From: <forumdesai@ta...> - 2009-11-10 09:05

Thanks,
   But my requirement is I know the key values but I am not aware where 
(as in which row ) it will appear.
    It is something like MAC address of the CPEs connected to my system.
    I know the MAC address but I dont know, rather I don want to take 
pains in doing table view and finding out the row.
    Is it possible then?

Dave Shield wrote:
> 2009/11/10 forumdesai@... <forumdesai@...>:
>   
>>       I have a standard Mib. It has a read only Table which has a
>> primary key. I am able to retrieve values for the table view.
>>         But I want to retrieve only a single row from whole table view.
>> I have the key details for that specific row.
>>     
>
>
> If you run 'snmpwalk' on the table, you'll see that the entries
> have the form:
>
>      MIB::object1.index1 =  someValue
>      MIB::object1.index2 =  someValue
>           :
>      MIB::object1.indexN =  someValue
>      MIB::object2.index1 =  someValue
>           :
>      MIB::objectM.indexN =  someValue
>
>
> If you run the command
>
>      snmpget ....   MIB::object1.indexX    MIB::object2.indexX    ...
> MIB::objectM.indexX
>
> this will return all of the specified objects  - i.e. one row of the table.
> If you don't actually need all of these column values, just specify the
> ones you are interested in.
>
> Dave
>
>

Re: Retrieval of a single row from read-only Table

From: Dave Shield <D.Shield@li...> - 2009-11-10 09:26

2009/11/10 forumdesai@... <forumdesai@...>:
>  But my requirement is I know the key values but I am not aware where
> (as in which row ) it will appear.
>   It is something like MAC address of the CPEs connected to my system.

Retrieving information from a MIB table is critically dependent on the
design of that table.   And in particular, the indexing of that table.

If you need to be able to retrieve information for a particular MAC address,
then you need a MIB table that is indexed by MAC address.   SNMP can
only work with the indexes that have been defined.   It can't handle
generating indexes for other columns on thefly.
   (It's the "simple" network management protocol, remember!)

If you need anything else, then you'd have to walk the MAC address
column, and look for the desired value.   Then you could extract the
index value for that instance, and use a GET request to retrieve the
rest of the row.   There's no real alternative.


Now all of this could be wrapped within a library routine, so the details
could be hidden from the end coder (e.g. see the AnyData::SNMP
perl module, which makes SNMP queries look like SQL).
But fundamentally, that's what would be needed.

Dave

Re: Retrieval of a single row from read-only Table

From: <forumdesai@ta...> - 2009-11-10 09:46

The table is indexed by the MAC address and it is a read only table. So 
I have added Private Mib parameter that takes the Key value
    from the user as a set parameter. I am able to retrieve the details 
of all the parameters for that key value and storing it into a structure.
    I want to display these values but when I run the for loop for 
requests, the request has the parameter details of the private MIB.
    Is there anyway I display the single row for the SET request?

       Ex.
       Table X is read only table
       It is indexed by MAC address.
   
       Table Y = private Mib
       "y" is Table Y parameter that is settable
       "y" fetches the MAC address from the user and fetches the data 
for that MAC address through Get a single row and
        stores it in a "x" structure (this structure has all parameters 
of Table X).
      
       I want to display the Table X one row based on whatever I have 
stored in "y" structure.
      
    How to retrieve these in single row format??
      
      
     

Dave Shield wrote:
> 2009/11/10 forumdesai@... <forumdesai@...>:
>   
>>  But my requirement is I know the key values but I am not aware where
>> (as in which row ) it will appear.
>>   It is something like MAC address of the CPEs connected to my system.
>>     
>
> Retrieving information from a MIB table is critically dependent on the
> design of that table.   And in particular, the indexing of that table.
>
> If you need to be able to retrieve information for a particular MAC address,
> then you need a MIB table that is indexed by MAC address.   SNMP can
> only work with the indexes that have been defined.   It can't handle
> generating indexes for other columns on thefly.
>    (It's the "simple" network management protocol, remember!)
>
> If you need anything else, then you'd have to walk the MAC address
> column, and look for the desired value.   Then you could extract the
> index value for that instance, and use a GET request to retrieve the
> rest of the row.   There's no real alternative.
>
>
> Now all of this could be wrapped within a library routine, so the details
> could be hidden from the end coder (e.g. see the AnyData::SNMP
> perl module, which makes SNMP queries look like SQL).
> But fundamentally, that's what would be needed.
>
> Dave
>
>

Re: Retrieval of a single row from read-only Table

From: Dave Shield <D.Shield@li...> - 2009-11-10 11:02

2009/11/10 forumdesai@... <forumdesai@...>:
>      Table X is read only table
>      It is indexed by MAC address.
>        Table Y = private Mib
>      "y" is Table Y parameter that is settable
>      "y" fetches the MAC address from the user and fetches the data for that
> MAC address through Get a single row and
>       stores it in a "x" structure (this structure has all parameters of
> Table X).
>          I want to display the Table X one row based on whatever I have
> stored in "y" structure.
>       How to retrieve these in single row format??


I'm having trouble visualising things properly from that description.
Could you post the output of walking the two tables
(suitably sanitized if necessary) and indicate exactly which
rows/objects you would be interested in for a typical scenario.

I.e. a concrete example of what you have in mind.

Dave

Re: Retrieval of a single row from read-only Table

From: Dave Shield <D.Shield@li...> - 2009-11-16 11:01

2009/11/16 forumdesai@... <forumdesai@...>:
> Hi,
>   PFA the result of the read only table i.e registeredSs table.
>   wmanIf2BsSsMacAddress is primary key. The Table is indexed by primary key.
>   With the help of snmpget command I want to know the details corresponding
> to wmanIf2BsSsMacAddress=01 02 03 04 05
>   how to retrieve it?


    snmpget   ....    wmanIf2BsSsBasicCid.1.2.3.4.5.6
wmanIf2BsSsPrimaryCid.1.2.3.4.5.6   ....

(Note that Mac Addresses will have six components, not five)

Dave

Re: Retrieval of a single row from read-only Table

From: <forumdesai@ta...> - 2009-11-16 11:33

I tried
1. snmpget -v 2c -c public 10.60.8.100 wmanIf2BsSsBasicCid.1.2.3.4.5.6
wmanIf2BsSsBasicCid.1.2.3.4.5.6: Unknown Object Identifier (Sub-id not 
found: (top) -> wmanIf2BsSsBasicCid)

2. snmpget -v 2c -c public 10.60.8.100 
WMAN-IF2-MIB::wmanIf2BsSsBasicCid.1.2.3.4.5.6     
WMAN-IF2-MIB::wmanIf2BsSsBasicCid.1.2.3.4.5.6 = No Such Instance 
currently exists at this OID

Its not retrieving the value , Is my format right?

Forum

Dave Shield wrote:
> 2009/11/16 forumdesai@... <forumdesai@...>:
>   
>> Hi,
>>   PFA the result of the read only table i.e registeredSs table.
>>   wmanIf2BsSsMacAddress is primary key. The Table is indexed by primary key.
>>   With the help of snmpget command I want to know the details corresponding
>> to wmanIf2BsSsMacAddress=01 02 03 04 05
>>   how to retrieve it?
>>     
>
>
>     snmpget   ....    wmanIf2BsSsBasicCid.1.2.3.4.5.6
> wmanIf2BsSsPrimaryCid.1.2.3.4.5.6   ....
>
> (Note that Mac Addresses will have six components, not five)
>
> Dave
>
>

Re: Retrieval of a single row from read-only Table

From: <forumdesai@ta...> - 2009-11-16 11:36

Also I get value if I type the following:

 snmpget -v 2c -c public 10.60.8.100 WMAN-IF2-MIB::wmanIf2BsSsBasicCid.1.0
WMAN-IF2-MIB::wmanIf2BsSsBasicCid.1.0 = Wrong Type (should be INTEGER): 
Gauge32: 1

Why does it say wrong type?


Dave Shield wrote:
> 2009/11/16 forumdesai@... <forumdesai@...>:
>   
>> Hi,
>>   PFA the result of the read only table i.e registeredSs table.
>>   wmanIf2BsSsMacAddress is primary key. The Table is indexed by primary key.
>>   With the help of snmpget command I want to know the details corresponding
>> to wmanIf2BsSsMacAddress=01 02 03 04 05
>>   how to retrieve it?
>>     
>
>
>     snmpget   ....    wmanIf2BsSsBasicCid.1.2.3.4.5.6
> wmanIf2BsSsPrimaryCid.1.2.3.4.5.6   ....
>
> (Note that Mac Addresses will have six components, not five)
>
> Dave
>
>

Re: Retrieval of a single row from read-only Table

From: Dave Shield <D.Shield@li...> - 2009-11-16 12:25

2009/11/16 forumdesai@... <forumdesai@...>:
> 2. snmpget -v 2c -c public 10.60.8.100
> WMAN-IF2-MIB::wmanIf2BsSsBasicCid.1.2.3.4.5.6
> WMAN-IF2-MIB::wmanIf2BsSsBasicCid.1.2.3.4.5.6 = No Such Instance currently
>            exists at this OID


Try   running "snmpgetnext" (or "snmpwalk") on WMAN-IF2-MIB::wmanIf2BsSsBasicCid
What do the results look like?



> Also I get value if I type the following:
>
> snmpget -v 2c -c public 10.60.8.100 WMAN-IF2-MIB::wmanIf2BsSsBasicCid.1.0
>  WMAN-IF2-MIB::wmanIf2BsSsBasicCid.1.0 = Wrong Type (should be INTEGER): Gauge32: 1

Hmmm....
   If that is the format of the OIDs, then it doesn't look as if this
MIB *is* indexed
by MAC address.   What does the MIB file look like?


>   Why does it say wrong type?

I have no idea.
It sounds as if there is an inconsistency between the implementation
and the MIB file.  Where did you get the implementation from?

Dave

Re: Retrieval of a single row from read-only Table

From: <forumdesai@ta...> - 2009-11-16 12:32

Ok I tried couple of things,
getnext gives me the value for the next element and I am able to 
retrieve the whole row by following command.

 snmpgetnext -v 2c -c public 10.60.8.100 
WMAN-IF2-MIB::wmanIf2BsSsMacAddress.1.2.3.4.5.6 
wmanIf2BsSsBasicCid.1.2.3.4.5.6 wmanIf2BsSsPrimaryCid.1.2.3.4.5.6 
wmanIf2BsSsSecondaryCid.1.2.3.4.5.6 
wmanIf2BsSsManagementSupport.1.2.3.4.5.6 
wmanIf2BsSsIpManagementMode.1.2.3.4.5.6 
wmanIf2BsSs2ndMgmtArqEnable.1.2.3.4.5.6 
wmanIf2BsSs2ndMgmtArqWindowSize.1.2.3.4.5.6 
wmanIf2BsSs2ndMgmtArqDnLinkTxDelay.1.2.3.4.5.6 
wmanIf2BsSs2ndMgmtArqUpLinkTxDelay.1.2.3.4.5.6 
wmanIf2BsSs2ndMgmtArqDnLinkRxDelay.1.2.3.4.5.6 
wmanIf2BsSs2ndMgmtArqUpLinkRxDelay.1.2.3.4.5.6 
wmanIf2BsSs2ndMgmtArqBlockLifetime.1.2.3.4.5.6 
wmanIf2BsSs2ndMgmtArqSyncLossTimeout.1.2.3.4.5.6 
wmanIf2BsSs2ndMgmtArqDeliverInOrder.1.2.3.4.5.6 
wmanIf2BsSs2ndMgmtArqRxPurgeTimeout.1.2.3.4.5.6 
wmanIf2BsSs2ndMgmtArqBlockSize.1.2.3.4.5.6 
wmanIf2BsSsVendorIdEncoding.1.2.3.4.5.6 
wmanIf2BsSsAasBroadcastPermission.1.2.3.4.5.6 
wmanIf2BsSsMaxTxPowerBpsk.1.2.3.4.5.6 
wmanIf2BsSsMaxTxPowerQpsk.1.2.3.4.5.6 
wmanIf2BsSsMaxTxPower16Qam.1.2.3.4.5.6 
wmanIf2BsSsMaxTxPower64Qam.1.2.3.4.5.6

Thanks!!!
 
And ,

 snmpgetnext -v 2c -c public 10.60.8.100 
WMAN-IF2-MIB::wmanIf2BsSsMacAddress.1.2.3.4.5.6
WMAN-IF2-MIB::wmanIf2BsSsBasicCid.1.2.3.4 = Wrong Type (should be 
INTEGER): Gauge32: 1

Only problem I face is why the wrong type is coming

whoever wrote is not there now, and this code was used only to get Table 
view request from the browser which works very well!



Dave Shield wrote:
> 2009/11/16 forumdesai@... <forumdesai@...>:
>   
>> 2. snmpget -v 2c -c public 10.60.8.100
>> WMAN-IF2-MIB::wmanIf2BsSsBasicCid.1.2.3.4.5.6
>> WMAN-IF2-MIB::wmanIf2BsSsBasicCid.1.2.3.4.5.6 = No Such Instance currently
>>            exists at this OID
>>     
>
>
> Try   running "snmpgetnext" (or "snmpwalk") on WMAN-IF2-MIB::wmanIf2BsSsBasicCid
> What do the results look like?
>
>
>
>   
>> Also I get value if I type the following:
>>
>> snmpget -v 2c -c public 10.60.8.100 WMAN-IF2-MIB::wmanIf2BsSsBasicCid.1.0
>>  WMAN-IF2-MIB::wmanIf2BsSsBasicCid.1.0 = Wrong Type (should be INTEGER): Gauge32: 1
>>     
>
> Hmmm....
>    If that is the format of the OIDs, then it doesn't look as if this
> MIB *is* indexed
> by MAC address.   What does the MIB file look like?
>
>
>   
>>   Why does it say wrong type?
>>     
>
> I have no idea.
> It sounds as if there is an inconsistency between the implementation
> and the MIB file.  Where did you get the implementation from?
>
> Dave
>
>