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Author(s) Olivier Bonaventure
Deadline No deadline
Submission limit No limitation
Category tags DNS

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Analysis of DNS packets


Question 1: Two DNS packets

Load the attached packet trace using wireshark and indicate which of the following affimations are correct.

If you do not have wireshark installed on your computer, you can see the packet trace in the question just below.

Question 2: The packet trace
# Length Summary Status
0 29 bytes Domain Name System (query)
1 29 bytes Domain Name System (query)

0000  c3050035001d2cdc  edc5012000010000  
0010  0000000003636f6d  0000020001        

0000  Ã..5..,ÜíÅ. ....
0010  .....com.....   
  • User Datagram Protocol, Src Port: 49925, Dst Port: 53
    • Source Port: 49925
      • Destination Port: 53
        • Length: 29
          • Checksum: 0x2cdc [unverified]
          • Domain Name System (query)
            • Transaction ID: 0xedc5
              • Flags: 0x0120 Standard query
                • 0... .... .... .... = Response: Message is a query
                  • .000 0... .... .... = Opcode: Standard query (0)
                    • .... ..0. .... .... = Truncated: Message is not truncated
                      • .... ...1 .... .... = Recursion desired: Do query recursively
                        • .... .... .0.. .... = Z: reserved (0)
                          • .... .... ..1. .... = AD bit: Set
                            • .... .... ...0 .... = Non-authenticated data: Unacceptable
                            • Questions: 1
                              • Answer RRs: 0
                                • Authority RRs: 0
                                  • Additional RRs: 0
                                    • Queries
                                      • com: type NS, class IN
                                        • Name: com
                                          • Name Length: 3
                                            • Label Count: 1
                                              • Type: NS (authoritative Name Server) (2)
                                                • Class: IN (0x0001)
                                            0000  c3050035001d2cdc  edc5012000010000  
                                            0010  0000000003636f6d  0000020001        

                                            0000  Ã..5..,ÜíÅ. ....
                                            0010  .....com.....   
                                            • User Datagram Protocol, Src Port: 49925, Dst Port: 53
                                              • Source Port: 49925
                                                • Destination Port: 53
                                                  • Length: 29
                                                    • Checksum: 0x2cdc [unverified]
                                                    • Domain Name System (query)
                                                      • Transaction ID: 0xedc5
                                                        • Flags: 0x0120 Standard query
                                                          • 0... .... .... .... = Response: Message is a query
                                                            • .000 0... .... .... = Opcode: Standard query (0)
                                                              • .... ..0. .... .... = Truncated: Message is not truncated
                                                                • .... ...1 .... .... = Recursion desired: Do query recursively
                                                                  • .... .... .0.. .... = Z: reserved (0)
                                                                    • .... .... ..1. .... = AD bit: Set
                                                                      • .... .... ...0 .... = Non-authenticated data: Unacceptable
                                                                      • Questions: 1
                                                                        • Answer RRs: 0
                                                                          • Authority RRs: 0
                                                                            • Additional RRs: 0
                                                                              • Queries
                                                                                • com: type NS, class IN
                                                                                  • Name: com
                                                                                    • Name Length: 3
                                                                                      • Label Count: 1
                                                                                        • Type: NS (authoritative Name Server) (2)
                                                                                          • Class: IN (0x0001)