[mrtg] Re: a little bit of help! :)

[Alex van den Bogaerdt]

Perhaps you should look on WWW for more info.
There are RFCs which describe SNMP.
Also see the SNMP newsgroups. (something like comp.protocols.snmp)

> 1.3.6.1 gets to the internet level. Then that splits into 1,2,3,4.
> 
and more (at least also 6)

> 2 is management. This is a standard MIB across all SNMP devices. It has
> transmission, interfaces, system, etc.
> 
Some parts are mandatory. As with any standard: some parts are more
standard than others and depending on the implementation you may encounter
differences.

> 4 is for vendors.
> 
> ie.
> 
> 1.3.6.1.4.1.9 is the cisco "tree".
> 

4 == private
4.1 == private.enterprises
4.1.9 == private.enterprises.cisco

> Now.. I have OID's for a 2500 CPU usage.They were under the 1.3.6.1.4.1.9
> tree. How comes they weren't under the 1.3.6.1.2 management section of the
> tree?
> 
Because Cisco can expand their private part of the tree at will. If
something is missing in the mgmt.mib-2 part they will do it somewhere else.
To make things even more complicated, in their private part of the tree
they sometimes move things around (from development to production).

> How do you know what is one, and what is in the other?
> 
This is in the Fine Manuals. In the cisco case you can look this up using
their website (and this probably true for most other vendors).
You need to find out which modules are supported by your device and OS
version. Then you go to the ftp site and get the modules. Import them
in MRTG and you can use the descriptive labels.

> And does the "MIB" only refer to the 1.3.6.1.2 sub-tree?
> 
AFAIK: no. There is only one MIB. This is the complete tree. You compile
a MIB from different modules and those modules form *the* mib.

> Now relating this to MRTG. I'm guessing MRTG can read from both of these
> sections of the SNMP table?
> 

MRTG will translate "1:public at device" into
"1.3.6.1.2.1.2.2.1.10.1&1.3.6.1.2.1.2.2.1.16.1:public at device"
and use that. You could do that yourself and use this in the config
file. You can also specify some other path through the tree and use
that. As far as MRTG is concerned, if it returns a counter it'll work.

You could write your own experimental SNMP daemon and use data from it
in MRTG. No problem (for MRTG; perhaps it is a problem for you and it
certainly would be a problem for me to accomplish :)

HTH
-- 
   __________________________________________________________________
 / alex at slot.hollandcasino.nl                  alex at ergens.op.het.net \
| work                                                         private |
| My employer is capable of speaking therefore I speak only for myself |
+----------------------------------------------------------------------+

--
* To unsubscribe from the mrtg mailing list, send a message with the
  subject: unsubscribe to mrtg-request at list.ee.ethz.ch
* The mailing list archive is at http://www.ee.ethz.ch/~slist/mrtg