See this post for an MPTCP introduction.
Let’s generate some MPTCP packets that we can analyze with mptcpanalyzer.
iperf -s starts the iperf server, by default listens on port 5201 (can be overriden with -p).
iperf -c localhost --cport 2042 -n 20b --cport allows to specify the client port in advance, which allows us to filter this connection in peculiar.
multipath-tcp.org runs an iperf server -n allows to limit the number of bytes.
Remember that by default iperf sends data from client to the server. This can be altered via --bidir to have it both ways or --reverse.
Wireshark > 3.0 understands the MPTCP protocol and can display the relative global sequence number (also called DSN: Data Sequence Number).