Fragmented packets in Wireshark capture

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Joined: 09/25/2018
Posts: 5
Fragmented packets in Wireshark capture


         I have downloaded automotive code from the website "" while executing the launch file, the protocol used for sending the data is IPV4 which i have observed in the wireshark but while executing the Helloworld example it is showing RTPS.

         What is the reason it is showing IPV4 but not the RTPS.



Joined: 11/14/2017
Posts: 4

Hello Sudarshan,

Does the wireshark capture log for the IPV4 packets look something like this? (in the 'Info' column):

Fragmented IP protocol (proto=UDP 17, off=0, ID=377b) [Reassembled in #175] 

If so - this is from a fragmented UDP packet, which can happen when sending large data packets such as the LiDAR data in the Automotive Case+Code example.   This packet fragmentation & reassembly normally happens transparently to the user and applications, but when observed via Wireshark the fragmentation is visible.

If you'd rather see the reassembled version of fragmented packets in Wireshark, get the most recent nightly build version (2.9.0 or greater) from the Wireshark automated build site at: -- this includes an RTI-contributed update to reassemble fragmented packets back into their complete form for viewing in Wireshark using the RTPS dissector, as if they were sent unfragmented.

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Joined: 09/23/2018
Posts: 6

Retitled:  From "Automative", Added "Wireshark" keyword