Wireshark not detecting file sets

edit

Using files created with a ring buffer capture option (-b) seems to work with a file set. Such files are saved in the format <name>_ddddd_ttt.<suffix>

where:

• <name> is the capture name.
• ddddd is the "sequence" number of the capture file, i.e. 00001, then 00002 etc.
• ttt is the time and date of the capture, e.g. 20190104181500.
• <suffix> is the capture file extension, e.g. pcapng.

You seem to need both the sequence number and the date\time to make the File Set feature work.