Re: [pysnmp-users] Sending an activation Sequence, getting timeout

[Diego M. <dmu...@gm...>]

Sadly I won't be able to work with the device until monday or tuesday
maybe. As soon as I can, I will send another email.

Meanwhile, I want to ask an extra question.
I have to create the OctetString based on 6 different values. What I
currently do is to create a hex string with the corresponding byte length
for each value, then use the binascii.unhexlify function and finally create
the OctetString with this result:

    message = duration_hex + activatePriority_hex + messageMemoryType_hex +
\
              messageNumber_hex + messageCRC_hex + deviceIp_hex
    message = binascii.unhexlify(message)

An example of the hex string is:
"ff ff ff 03 00 3c 2f f5 c0 a8 01 de" (blank spaces added to read easily)
where:
duration_hex = ff ff
activatePriority_hex = ff
messageMemoryType_hex = 03
messageNumber_hex = 00 3c
messageCRC_hex = 2f f5
deviceIp_hex = c0 a8 01 de

Is there a cleaner way to create the OctetString?

2015-11-06 20:14 GMT-03:00 Ilya Etingof <il...@gl...>:

> Hi Diego,
>
> Try to enable pysnmp debug and see what OID and what value type (is it
> still OctetString?) is being sent in the second case:
>
> from pysnmp import debug
>
> debug.setDebug(debug.Debug(‘msgproc’))
>
> -ilya
>
>
> On 06 Nov 2015, at 22:21, Diego Muñoz <dmu...@gm...> wrote:
>
> Hi Ilya, I am using the correct community, and I could successfully change
> the image with this code:
>
> from pysnmp.entity.rfc3413.oneliner import cmdgen
> from pysnmp.proto.rfc1902 import OctetString
>
> device_ip = '192.168.1.222'
> port = 6000
>
> cmdGen = cmdgen.CommandGenerator()
>
> a = '\xff\xff\xff\x03\x00\x3c\x2f\xf5\x00\x00\x00\x00'
>
> errorIndication, errorStatus, errorIndex, varBinds = cmdGen.setCmd(
>     cmdgen.CommunityData('public'),
>     cmdgen.UdpTransportTarget((device_ip, port)),
>     ('1.3.6.1.4.1.1206.4.2.3.6.3.0', OctetString(a)),
>     lookupNames=True, lookupValues=True
> )
>
> I could finally understand the bytes in the sequence and get the OID of
> the object and the Octet String argument that I have to provide. This octet
> string (variable "a" in the code I wrote) contains 6 parameters, including
> the type of memory (03) and the memory number that corresponds to the image
> (00 3c).
>
> Now, what I don't get is why the new code works, when the only difference
> is the way I refer to the function I call:
>
> Code that does not work:
>     (cmdgen.MibVariable('NTCIP1203_v03_38', 'dmsActivateMessage', 0),
>         OctetString(a)),
>
> Code that works:
>     ('1.3.6.1.4.1.1206.4.2.3.6.3.0', OctetString(a)),
>
>
> 2015-11-06 17:29 GMT-03:00 Ilya Etingof <il...@gl...>:
>
>>
>> Hi Diego,
>>
>> Make sure you are using correct community name, for SET queries it is
>> frequently defaulted to ‘private’.
>>
>> If you show me the byte-string that works, I can possibly come up with
>> corresponding SNMP message.
>>
>> -ilya
>>
>> > On 05 Nov 2015, at 17:02, Diego Muñoz <dmu...@gm...> wrote:
>> >
>> > Hello everyone,
>> >
>> > I have been working with NTCIP for only one week, and I need to change
>> an image on a device by sending a SNMP activation message. I have been
>> given the corresponding MIB, and a byte sequence of a SNMP message.
>> >
>> > I recently understood how the sequence is formed, and its components. I
>> identified the MIB OID to activate the image, and identified the parameters
>> that I need to give to the function. By editing the byte sequence, I can
>> successfully send the message and change the image with python sockets
>> using UDP. I also can successfully get information from the device with
>> PySNMP and the getCmd function.
>> >
>> > The problem I have is that I try to setCmd the message and I only get a
>> Timeout from the device. This is the code of my setCmd
>> >
>> > from pysnmp.entity.rfc3413.oneliner import cmdgen
>> > from pysnmp.proto.rfc1902 import OctetString
>> >
>> > device_ip = '192.168.1.222'
>> > port = 6000
>> >
>> > cmdGen = cmdgen.CommandGenerator()
>> >
>> > # this variable includes the parameters I need to send to the device
>> > a = '\xff\xff\xff\x03\x00\x0a\x2f\xf5\x00\x00\x00\x00'
>> >
>> > errorIndication, errorStatus, errorIndex, varBinds = cmdGen.setCmd(
>> >     cmdgen.CommunityData('public'),
>> >     cmdgen.UdpTransportTarget((device_ip, port)),
>> >     (cmdgen.MibVariable('NTCIP1203_v03_38', 'dmsActivateMessage', 0),
>> >         OctetString(a)),
>> >     lookupNames=True, lookupValues=True
>> > )
>> >
>> > I don't know which part is wrong, I would appreciate any help.
>> > Regards,
>> > Diego
>>
>>
>>
>
>