mptcpd - Man Page

multipath TCP daemon


mptcpd[-d?V] [-l DEST] [--debug] [--addr-flags=FLAGS] [--notify-flags=FLAGS] [--plugin-dir=DIR] [--path-manager=PLUGIN] [--load-plugins=PLUGINS][--help] [--usage] [--log=DEST][--version]


mptcpd is a daemon for Linux based operating systems that performs multipath TCP (see IETF RFC 8684) path management related operations in the user space.  It interacts with the Linux kernel through a generic netlink connection to track per-connection information, available network interfaces, request new MPTCP subflows, handle requests for subflows, etc.


mptcpd accepts the following command line options:


enable debug log messages


display mptcpd help information


display brief mptcpd usage information

-l DEST--log=DEST

log output to DEST, where DEST can be stderr, syslog or journal


set flags for announced address, where FLAGS is a comma separated list containing one or more of the flags subflow, signal, backup, and fullmesh that plugins that deal with the in-kernel path manager may use when advertising addresses, e.g. --addr-flags=subflow


address notification flags, where FLAGS is a comma separated list containing one or more of the following flags:


notify plugins of the addresses that exist at mptcpd start


ignore (do not notify) [ipv6] link local address updates


ignore (do not notify) host (loopback) address updates


notify address only if a default route is available from such address and the related device. If the route check fails, it will re-done after a little timeout, to allow .e.g. DHCP to configure the host properly. Complex Policy routing configuration may confuse or circumvent this check.

These flags determine whether mptpcd plugins will be notified when related addresses are updated, e.g. --notify-flags=existing,skip_link_local,check_route


set plugin directory to DIR


set default path manager plugin to PLUGIN, overriding plugin priorities


set plugins to load on startup, where PLUGINS is a comma separated list containing one or more plugin names


display mptcpd version information



Location of the mptcpd system configuration file.

Reporting Bugs

Report bugs to

See Also


Referenced By

mptcpd_selinux(8), mptcpize(8).

2022-08-19 Multipath TCP Daemon System Management Commands