They have a handle on this stuff: https://datatracker.ietf.org/doc/rfc6897/?include_text=1 https://datatracker.ietf.org/doc/rfc6897/?include_text=1 Basically

They have a handle on this stuff: https://datatracker.ietf.org/doc/rfc6897/?include_text=1 https://datatracker.ietf.org/doc/rfc6897/?include_text=1 Basically if you bind an address, MP is disabled. If not, then MP will happen by default. If you had code that was doing MP with multiple connections before, it was binding interfaces on multiple sockets and will still work. The idea is that MPTCP is desirable and should be used if possible. Also you get new sockopts for handling the MPTCP stuff like TCP_MULTIPATH_ENABLE and TCP_MULTIPATH_ADD if you want to control the MP stuff in MPTCP.