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What does this ARP packet mean, or even just what bytes correspond to which fields?
0000 FF FF FF FF FF FF 00 00 C0 93 19 00 08 06 00 01
0010 08 00 06 04 00 01 00 00 C0 93 19 00 C0 99 B9 64
0020 FF FF FF FF FF FF C0 99 B9 32 00 00 55 00 00 DC
0030 00 6C 00 D6 00 00 00 A3 00 00 00 41
This is on the study guide for an networking exam that I am woefully unprepared for. The textbook says that the ARP packet is 20-24 bytes, which doesnt fit this data and its way too small to be an ethernet frame. However the series of hexadecimal FF's definately matches the broadcast output of ethernet. So confused. Help please.
That frame is 60 bytes long... the minimum is 64 bytes, and the drivers for most NICs will not send you the 4-byte CRC at the end of the frame... so that is a valid ethernet ARP frame; remember that ethernet frames are required to be a minimum of 64 bytes (measured from destination mac addr to the end of the CRC), and they get padded to that value if the upper protocols (i.e. ARP) don't use the minimum ethernet payload. Use wireshark to decode the it.
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I have a proprietary client application that sends and receives TCP data packets to|from the network device like this:
Sent: [14 bytes]
01 69 80 10 01 0E 0F 00 00 00 1C 0D 64 82 .i..........d.
Received: [42 bytes] [+00:000]
01 69 80 10 01 2A 00 D0 DC CC 0C BB C0 40 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 .i...*.......#..................
00 00 00 00 00 00 1C 0D F6 BE ..........
or see the picture
I need to make same requests with Lua. I've found some working examples (for ex) for such communications, but I can't understand what string should I give as an argument for
tcp:send("string");
Should I give it a string of hex? I.e.
'01698010010E0F0000001C0D6482'
Or first convert hex to ACSII? If so, then how (zeroes doesn't convert to symbols)?
You should give it the string you want to send. If you write "016980..." it's a string containing decimal values 48 (ascii digit 0), 49 (ascii digit 1), 54 (ascii digit 6), and so on. Which is not what you want to send. You want to send decimal values 1, 105 (hex 69), 128 (hex 80) and so on.
Luckily, Lua strings can hold any bytes (unlike e.g. Python strings). So you just have to write a string with those bytes. You can write any byte into a string using \x and then a 2-digit hex code. So you could write your call like this:
tcp:send("\x01\x69\x80\x10\x01\x0E\x0F\x00\x00\x00\x1C\x0D\x64\x82")
If you are using a Lua version older than 5.2, \x is not available, but you can still use \ and a 3-digit decimal code.
I have SL7000 meter and GSM Modem iRZ. When i send by using RS-485 cable - everything work. But when i'm trying to use GSM modem i'm getting issues.
When i send SNRM like this:
7E A0 0A 00 22 00 51 03 93 6A 34 7E
I get normal UA.
But when i try to send SNRM like this:
7E A0 21 00 22 00 51 03 93 6B 21 81 80 12 05 01 80 07 04 00 00 00 02 08 04 00 00 00 01 3D 93 7E (It's from DXDLMSDirector)
I get nothing. Absolutely!
Maybe there is some trick to use hdlc with gsm modem? Maybe special delays or something?
If both of these frames work via the RS-485, and not via the GSM, then there are a couple of possible answers:
1) the addressing you are using is not permitted if this is a seperate port
2) if it is the same port on the meter, then the GSM Modem is not directing traffic to the same RS485 address
I am using trying to add the following IAS zone devices (from HEIMAN) to my ZCL co-ordinator(CIE) + IoT gateway (from NXP)
emergency button - gets added easily and triggers successfully
door sensor - joins the network but no enrolment process is seen
Q1. Why is it such that one device undergoes enrolment process correctly and the other doesn't? My understanding is that the ZCL stack should do all the enrolment activities. Am I correct?
Q2. I tried writing IEEE address of the CIE to the node's cluster(0x0500) attribute (0x0010) of attribute type (0xf0). But no response. How to tackle this issue?
For a CIE device, the enrolment is more complex and the ZCL stack will not perform this for you (although this may depend on the stack, and any add-on features it provides).
A CIE device may perform its own service discovery using the ZDO Match Descriptor functions. It may send a MatchDescriptorRequest report looking for an IAS server, and you will need to respond with the MatchDescriptorResponse to report that you support this. Typically the request will be looking for the IAS Zone Server cluster (0x500), but you should inspect the packets and respond appropriately. See 2.4.3.1.7 Match_Desc_req, and 2.4.4.1.7 Match_Desc_rsp of the ZigBee specification. If an IAS device is looking for a zone controller, it may not accept any requests until it receives this response, and in fact some devices may leave the network if they don't find the services they are requesting.
Next, it may enrol with the IAS service by sending the ZoneEnrollRequest command, and your application will need to respond to this with the ZoneEnrollResponse to tell the device that it is now enrolled in your system. Refer to 8.2.2.4.2 Zone Enroll Request Command in the ZCL specification.
From your traces, it is hard to say what is happening as the log viewer doesn't provide any information on the contents of the Data Request frames in this view. However, we can see a lot of frames being sent from the device to the coordinator, and it is likely that it is performing one, or both of the discovery services discussed above. You should inspect the requests to find out what they are, and check the appropriate sections of the ZigBee specification, or the ZigBee Cluster Library Specification.
CIE IEEE Address to IAS zone worked successfully. Tested using Xbee s2c.
Explicit Addressing Command Frame (API 2)
7E 00 22 7D 31 01 28 6D 97 00 01 04 2B 7D 5D FF FE E8 01 05 00 01 04 00 20 00 01 02 10 00 F0 6B 7A 29 41 00 A2 7D 33 00 FD
Start delimiter: 7E
Length: 00 22 (34)
Frame type: 11 (Explicit Addressing Command Frame)
Frame ID: 01 (1)
64-bit dest. address: 28 6D 97 00 01 04 2B 7D
16-bit dest. address: FF FE
Source endpoint: E8
Dest. endpoint: 01
Cluster ID: 05 00
Profile ID: 01 04
Broadcast radius: 00 (0)
Transmit options: 20
RF data: 00 01 02 10 00 F0 6B 7A 29 41 00 A2 13 00
Checksum: FD
Explicit RX Indicator (API 2)
7E 00 16 91 28 6D 97 00 01 04 2B 7D 5D A3 87 01 E8 05 00 01 04 21 18 01 04 00 3A
Start delimiter: 7E
Length: 00 16 (22)
Frame type: 91 (Explicit RX Indicator)
64-bit source address: 28 6D 97 00 01 04 2B 7D
16-bit source address: A3 87
Source endpoint: 01
Destination endpoint: E8
Cluster ID: 05 00
Profile ID: 01 04
Receive options: 21
RF data: 18 01 04 00
Checksum: 3A
Coding a app using serial port, when debugging, I have been compelled to work with low level (link control) protocol.
And here my problems begun.
Sniffer gives me values:
IOCTL_SERIAL_SET_BAUD_RATE 80 25 00 00 means baud rate 9600. Well, 00 c2 01 00 means 115200. How is it possible to guess it?
IOCTL_SERIAL_SET_TIMEOUTS 32 00 00 00 05 00 00 00 00 00 00 00 60 09 00 00 00 00 00 00 - what does this mean? What is the value? What is the range of admissible values? I had read MSDN - "Setting Read and Write Timeouts for a Serial Device", for example. Blah-blah-blah, but no any value. What to read? How to understand sniffer data? And how to control it?
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I just want to ask if someone have an idea about the type of this hash or encryption?
PWB1AD8APWA/AD8APWA/AD8AGGA/AD8APWA/AD8APWA/AA4ARQBCAA==
It is definitely base64. But what is encoded in the base64 is next question.
$ echo "PWB1AD8APWA/AD8APWA/AD8AGGA/AD8APWA/AD8APWA/AA4ARQBCAA==" | openssl enc -d -base64 -out b.1 ; hexdump b.1
00000 3d 60 75 00 3f 00 3d 60 3f 00 3f 00 3d 60 3f 00 =`u.?.=`?.?.=`?.
00010 3f 00 18 60 3f 00 3f 00 3d 60 3f 00 3f 00 3d 60 ?..`?.?.=`?.?.=`
00020 3f 00 0e 00 45 00 42 00 ?...E.B.
This is the decode of the base64. Now you would have to figure out what this data could be.
One clue is that it is 40 bytes. Only some encryption algorithms can generate 40 bytes (Not
a multiple of 16). For example aes256 would be a multiple of 16, where des is multiples of 8.