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Re: SNMP



Thanks Jeremy the doc from cisco is great unfortunately when i run
snmpwalk command to find out the physical address the switch CPU runs
100% and i lose conectivity :(
Jeremy Winder wrote:
> There is, however it becomes a multi-step process. While at a previous
> employer I wrote a poof of concept perl script for a security conference
> that would pull all of the vlan, and cam tables from switches and map
> the layer 2 network. It was later expanded to allow searching for the
> exact port of which switch a machine with a mac address was plugged
> into. I'll see if I still have it kicking around somewhere.
>
> In the meantime this document from Cisco may help with the multi-step
> process it will take. 
> http://www.cisco.com/en/US/tech/tk648/tk362/technologies_tech_note09186a0080094a9b.shtml
>
> They talk about finding the vlan then using it as part of the community
> string, such as public@1, some switches need this, other won't return
> anything if it is used. So test your switches both ways to find the one
> that works.
>
> If you don't have the actual MIBs, you can use the numeric OID which
> Cisco has included in the document above.
>
> Hope this helps,
>
> Jeremy
>
>
> On Wed, 2009-03-25 at 16:51 +0200, Alex wrote:
>   
>> Thank you for your suggestions,  i will try it an see if it's faster
>> than my option with ssh and key auth :)
>>
>> Another question : Is there an OID to find out on an inteligent switch (
>> ZTE-2609) what physical address is on each port?
>> Now i've done this using netcat but this is very slow and i have almost
>> 300 switches on my network
>> I searched google and the MIBs from ZTE but came out with no results
>>
>>
>>
>> Jeremy Winder wrote:
>>     
>>> This is going to be an interesting project. The first problem is snmp
>>> works on gets and sets. So you either get an object's value or you set
>>> and object's value. You can not do both in the same operation. In your
>>> example, you will need to setup an object that you can set the IP
>>> address you want arped to. Then you need to setup an object that you can
>>> get the results back from. To have box B arp 10.0.0.1, you would do a
>>> two step operation. First a snmpset REMOTEARP-OID 10.0.0.1, then a
>>> snmpget REMOTEARP-OID.
>>>
>>> Make sense? I hope so. I'm not completely awake yet this morning.
>>>
>>> For the get part you could use the NET-SNMP-EXTEND-MIB, I suggest google
>>> for examples. As for the set part, I'm not going to be much help as I've
>>> not done it.
>>>
>>> Another, option would be to walk the arp table OID
>>> (IP-MIB::ipNetToPhysicalPhyAddress) and look for your IP address.
>>> However, if machine B hasn't talked to the IP in awhile, it may not be
>>> in the arp table anymore. Also, during a quick test I found it takes
>>> Linux a minute or so between when a new address enters the arp table and
>>> when it is exposed via snmp. So your mileage my vary.
>>>
>>> Hope this helps,
>>>
>>> Jeremy
>>>
>>> On Wed, 2009-03-25 at 14:13 +0200, Alex wrote:
>>>   
>>>       
>>>> Hi, i want to run a script just interrogating a specific OID defined by
>>>> me, to be more specific i have two boxes A and B,
>>>> from box A i want to use snmpwalk to trigger a script which will run
>>>> arping on  box B that's simple but i want to pass the ip which i want to
>>>> arping via  snmpwalk from box A, does anywone have a clue how can i do this?
>>>>
>>>>
>>>>     
>>>>         
>>>   
>>>       
>>     
>
>   


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