From MultiPath TCP - Linux Kernel implementation

Users: UseMPTCP

If you are looking for MPTCP in Linux >= v5.6:

https://mptcp.dev

For Linux <= 5.4, you can stay on this website.

Use MPTCP

If you have correctly installed the MPTCP-kernel and configured the routing tables as needed, you can start using MPTCP

Check

This server (multipath-tcp.org) is running the latest build of our kernel. Thus, every time you connect to this server you will be using MPTCP.

Download some files http://multipath-tcp.org/snapshots.

You can also visit http://amiusingmptcp.de to see how well your network supports MPTCP on different port-numbers.

No MPTCP at all

If it looks like you don't use MPTCP at all, please check these points:

• Are you using a kernel with MPTCP?
  • sudo dmesg | grep MPTCP
• Is MPTCP enabled?
  • sysctl net.mptcp.mptcp_enabled
• Does the application create an MPTCP connection?
  • tcpdump -n -i <interface> tcp | grep mptcp
• Is MPTCP blocked somewhere between the client and the server?
  • Visit http://amiusingmptcp.de and check the different ports
  • sudo tracebox -p 'IP/tcp{dst=443}/MPCAPABLE' multipath-tcp.org (See Tools)
  • Feel free to report such issues to the network owner (ISP, etc.): most of the time, it is a mistake or due to some default configurations.

MPTCP only with one path

If MPTCP is used but only with one path, please check:

• Did you configure a path manager on the client side to establish more subflows?
  • e.g. sysctl -w net.mptcp.mptcp_path_manager=fullmesh
  • ConfigureMPTCP
• Did you configure a path manager on the server side to announce more available IP addresses?
  • e.g. fullmesh
  • ConfigureMPTCP
• Did you configure the routing?
  • ConfigureRouting
• Is MPTCP blocked on some paths?
  • See above about tracebox.