I am trying to make a snmp trap receiver, that can capture all the incoming snmp trap from UDP 162 port and translate them into meaningful alarms. The image I attached is a sample trap that I captured using wireshark.
My script can capture and parse all different parts of the packet, but I got stuck in the variable binding section. Im not sure how I can re-present this section into some user friendly information (that I can show in the user interface). How do I know these sequences are sending something alarming or just some general information regarding the agent node? are these sequences independent information each or together they are forming one piece of information?
As with any incoming data, it is important to know what kind of info you are getting. The variable bindings of an SNMP trap is basically a hierarchical piece of data. Every object or element represents it's own data. If you take the first element (1.3.6.1.2.1.1.3.0) you will find that this contains the sysUpTime (see link), which is pretty general.
Most of the other elements seem to start with 1.3.6.1.4.1.4421 which appears to be object from a specific vendor; Santera systems (see link). You might want to try and contact them in order to obtain their MIB (Management Information Base), which should have details on what kind of data is shown in these fields.
It might be possible to find info like this online, have a look at the XML-files on this link.
Related
I am performing a multilayer packet capture on Windows using the built-in NDIS capture service in order to determine where in the stack packets for my application are being dropped. When viewing the resulting ETL file in Microsoft Message Analyzer, I'm provided with data points containing two items in particular that I'm looking for:
MiniportIfIndex - this corresponds with the adapter interface ID, which I can translate into a logical name by running Get-NetAdapter in PowerShell (as one method).
LowerIfIndex - this is the specific layer/filter of the NDIS stack that the packet is progressing through during the traffic flow and is the subject of this question.
I have yet to find a way to gather what specific layer/filter the lowerIfIndex is referencing. I found this article which led me to the WMI class MSNdis_EnumerateReceiveFilters that I was hoping would give me an output similar to that of Get-NetAdapter, listing the logical name of the filter as well as the corresponding ID. When I try to run the command in the format similar to how the MSDN article references, I'm always receiving an 'incorrect parameter' stop error.
One other command Get-NetAdapterBinding appears to display the logical names of the NDIS filters/layers, but no corresponding ID.
Is anyone aware of a way to correlate the lowerIfIndex to a filter name?
Most of the examples provided for sending SNMP traps are simple ones like the one below.
snmptrap -v 1 -c public host TRAP-TEST-MIB::demotraps localhost 6 17 '' \
SNMPv2-MIB::sysLocation.0 s "Just here"
Take any MIB file, they contain many complex object groups, for example, systemGroup contains sysLocation, sysName, etc.
Could someone help in bringing out examples to show the way how to send snmp traps which includes such OBJECT-GROUPS. Adding one more question here, Does SNMPTRAPD support internationalization?
It is really bad practice to define the SNMP notification (trap or inform) the way that it contains the entire OBJECT GROUP or even worse the entire SNMP table. The reason is that you don't really need all these variables anyway. The other reason is that the packet/PDU is limited by MTU size. So it is possible that you'll not be able to send the data within single UDP packet due to its size.
The proper scenario would be to have few varbinds and you could also initiate some polling cycle to find out what happens if you need more details when you receive such trap.
SNMPTRAPD and NET-SNMP library in general do not support internationalization (UNICODE). The library is limited to ASCII charset only.
There are commercial products on the market including NetDecision TrapVision and some other that fully support UTF-8 internationalization.
I'm very new to settop box project.Is there any materials available to study the basics of its internals and the working of it.I dont know how to start understand about it.I was looking for the architecture of middleware,DCCM and other components.I need to know how these components interact with each other.I need to know how by pressing a particular event in the EPG menu we could able to get the event corresponding to the service.I need to know the interaction between the tables.How to set the reminder in EPG and how the interactive TV works.
This is only a very partial answer to your question. Rather i would say, this is the first preliminary work you must accomplish before getting deeper into interactivity.
The tutorial here on PSIP: Program specific information show how the ATSC (or DVB is similar) is organized in the form of periodic tables including some tables that indicate EPG. By reading and processing such tables you will be able to accomplish the desired work.
Essentially, EPG table contains the information about the program and its respective time. And the actual timing information is contained in the TDT and TOT table. These tables tells the STB's the current time (on wall clock). Once, the respective time occurs, as per the TDT/TOT, the notification action can fire.
Below here are two more important references to Transport stream structures.
PSIP tutorial
The ATSC transport layer, including program and system information protocol (PSIP)
Please read the above pre-requsite and then refine your question.
I am using some SNMP traps for monitoring of applications. Now I was told that some monitoring systems might have problems if the order of the attributes within the the traps was not the same as defined in the MIB. From the Complexity of the OIDs that could easily be used to re-order the attributes I was surprised by this, so I tried to find the relevant section of the RFC, but I could neither find something that said any ordering is allowed nor anything that said it is important. In other secondary documentation about SNMP I was not able to find anything usefull either.
So this is more a curiosity question, that could however also help in further projects using SNMP. Could anyone point me to the correct documentation as far as this problem is concerned. Or is this something that one software might handle while other software might not handle this and I should check the actual documentation for that software?
I found the relevant document.
Section 3.1.2 specifies:
The VARIABLES clause, which need not be present, defines the
ordered sequence of MIB objects which are contained within
every instance of the trap type. Each variable is placed, in
order, inside the variable-bindings field of the SNMP Trap-
PDU. Note that at the option of the agent, additional
variables may follow in the variable-bindings field.
Thanks to the person who pointed this out to me.
ETL is pretty common-place. Data is out there somewhere so you go get it. After you get it, it's probably in a weird format so you transform it into something and then load it somewhere. The only problem I see with this method is you have to write the transform rules. Of course, I can't think of anything better. I supposed you could load whatever you get into a blob (sql) or into a object/document (non-sql) but then I think you're just delaying the parsing. Eventually you'll have to parse it into something structured (assuming you want to). So is there anything better? Does it have a name? Does this problem have a name?
Example
Ok, let me give you an example. I've got a printer, an ATM and a voicemail system. They're all network enabled or I can give you connectivity. How would you collect the state from all these devices? For example, the printer dumps a text file when you type status over port 9000:
> status
===============
has_paper:true
jobs:0
ink:low
The ATM has a CLI after you connect on port whatever and you can type individual commands to get different values:
maint-mode> GET BILLS_1
[$1 bills]: 7
maint-mode> GET BILLS_5
[$5 bills]: 2
etc ...
The voicemail system requires certain key sequences to get any kind of information over a network port:
telnet> 7,9*
0 new messages
telnet> 7,0*
2 total messages
My thoughts
Printer - So this is pretty straight-forward. You can just capture everything after sending "status", split on lines and then split on colons or something. Pretty easy. It's almost like getting a crap-formatted result from a web service or something. I could avoid parsing and just dump the whole conversation from port 9000. But eventually I'll want to get rid of that equal signs line. It doesn't really mean anything.
ATM - So this is a bit more of a pain because it's interactive. Now I'm approaching expect or a protocol territory. It'd be better if they had a service that I could query these values but that's out of scope for this post. So I write a client that gets all the values. But now if I want to collect all the data, I have to define what all the questions are. For example, I know that the ATM has more bills than $1 and $5 so I'd have a complete list like "BILLS_1 BILLS_5 BILLS_10 BILLS_20". If I ask all the questions then I have an inventory of the ATM machine. Of course, I still have to parse out the results and clean up the text if I wanted to figure out how much money is left in the ATM machine. So I could parse the results and figure out the total at data collection time or just store it raw and make sense of it later.
Voicemail - This is similar to the ATM machine where it's interactive. It's just a bit weirder because the key sequences/commands aren't "get key". But essentially it's the same problem and solution.
Future Proof
Now what if I was going to give you an unknown device? Like a refrigerator. Or a toaster. Or anything? You'd have to write "connectors" ahead of time or write a parser afterwards against some raw field you stored earlier. Maybe in the case of these very limited examples there's no alternative. There's no way to future-proof. You just have to understand the new device and parse it at collection or parse it after the fact (your stored blob/object/document).
I was thinking that all these systems are text driven so maybe you could create a line iterator type abstraction layer that simply requires the device to split out lines. Then you could have a text processing piece that parses based on rules. For the ATM device, you'd have to write something that "speaks ATM" and turns it into lines which the iterator would then take care of. At this point, hopefully you'd be able to say "I can handle anything that has lines of text".
But then what will you call these rules for parsing the text? "Printer rules" might as well be called "printer parser" which is the same to me as "printer transform". Is there a better term for all of this?
I apologize for this question being so open ended. :)
When your sources of information are as disparate as what you illustrate then you have no choice but to implement the Transform in order to bring the items into a common data repository. Usually your data sources won't be this extreme, the data will all be related in some way but you may be retrieving it from different sources (some might come from a nicely structured database, some more might come from an Excel or XML or text file, some more might come from a web service call, etc).
When coding up a custom ETL application, a common pattern that is used is the Provider model, this enables you to write a whole bunch of custom providers to load/query and then transform the data. All the providers will implement a common interface with some relatively common function definitions (for example QueryData(), TransformData()), but the implementation of those methods will be wildly different depending on the data source being dealt with - the interface just gives a common way to deal with all the different providers. You can then use an XML configuration file to dictate which providers to run and any other initial settings they may require. Tools like SSIS abstract this stuff away for you by giving you a nice visual designer, but you can still get down and dirty and write your own code which it calls.
Now what if I was going to give you an unknown device? Like a refrigerator. Or a toaster.
No problem, i would just write a new provider, which can sit in its very own assembly (dll), so it can be shipped (or modified, upgraded, etc) in isolation to any other providers i already have. Or if i was using SSIS then i would write a new DTS package.
I was thinking that all these systems are text driven so maybe you could create a line iterator type abstraction layer ... Then you could have a text processing piece that parses based on rules.
Absolutely - you can have a base class containing common functionality which several different providers can implement, and each provider can use its own set of rules which could be coded into it or they can be contained in an external configuration file.
So I could parse the results and figure out the total at data collection time or just store it raw and make sense of it later.
Use whichever approach makes sense for the data you are grabbing. It is also quite common for an ETL process to dump its data into a staging area (like some staging tables in a database) while the data is all being aggregated and accumulated, and then further process it to link related data and perform calculations. In the case of your ATM it may not be necessary to calculate a cash balance at ETL time because you can easily calculate it at any time in the future.