# ip-mptcp - MPTCP path manager configuration - man(8) - [phpMan] [_IP-MPTCP_(8)](https://www.chedong.com/phpMan.php/man/IP-MPTCP/8/markdown) Linux [_IP-MPTCP_(8)](https://www.chedong.com/phpMan.php/man/IP-MPTCP/8/markdown) ## NAME ip-mptcp - MPTCP path manager configuration ## SYNOPSIS **ip **[ _OPTIONS_ ] **mptcp **{ **endpoint **| **limits **| **help **} **ip mptcp endpoint add _**IFADDR_ [ **port _**PORT_ ] [ **dev _**IFNAME_ ] [ **id _**ID_ ] [ _FLAG-LIST_ ] **ip mptcp endpoint delete id _**ID_ [ _IFADDR_ ] **ip mptcp endpoint change **[ **id _**ID_ ] [ _IFADDR_ ] [ **port _**PORT_ ] CHANGE-OPT **ip mptcp endpoint show **[ **id _**ID_ ] ### ip mptcp endpoint flush _FLAG-LIST_ := [ _FLAG-LIST_ ] _FLAG_ _FLAG_ := [ **signal **| **subflow **| **backup **| **fullmesh **] _CHANGE-OPT_ := [ **backup **| **nobackup **| **fullmesh **| **nofullmesh **] **ip mptcp limits set **[ **subflow _**SUBFLOW_NR_ ] [ **add_addr_accepted _**ADD_ADDR_ACCEPTED_NR_ ] ### ip mptcp limits show ### ip mptcp monitor ## DESCRIPTION MPTCP is a transport protocol built on top of TCP that allows TCP connections to use multiple paths to maximize resource usage and increase redundancy. The ip-mptcp sub-commands allow configuring several aspects of the MPTCP path manager, which is in charge of subflows cre‐ ation: The **endpoint **object specifies the IP addresses that will be used and/or announced for addi‐ tional subflows: ip mptcp endpoint add add new MPTCP endpoint ip mptcp endpoint delete delete existing MPTCP endpoint ip mptcp endpoint show get existing MPTCP endpoint ip mptcp endpoint flush flush all existing MPTCP endpoints _IFADDR_ An IPv4 or IPv6 address. When used with the **delete id **operation, an **IFADDR **is only in‐ cluded when the **ID **is 0. _PORT_ When a port number is specified, incoming MPTCP subflows for already established MPTCP sockets will be accepted on the specified port, regardless the original listener port accepting the first MPTCP subflow and/or this peer being actually on the client side. _ID_ is a unique numeric identifier for the given endpoint **signal **The endpoint will be announced/signaled to each peer via an MPTCP ADD_ADDR sub-option. Upon reception of an ADD_ADDR sub-option, the peer can try to create additional sub‐ flows, see **ADD_ADDR_ACCEPTED_NR.** ### subflow If additional subflow creation is allowed by the MPTCP limits, the MPTCP path manager will try to create an additional subflow using this endpoint as the source address af‐ ter the MPTCP connection is established. **backup **If this is a **subflow **endpoint, the subflows created using this endpoint will have the backup flag set during the connection process. This flag instructs the peer to only send data on a given subflow when all non-backup subflows are unavailable. This does not affect outgoing data, where subflow priority is determined by the backup/non- backup flag received from the peer ### fullmesh If this is a **subflow **endpoint and additional subflow creation is allowed by the MPTCP limits, the MPTCP path manager will try to create an additional subflow for each known peer address, using this endpoint as the source address. This will occur after the MPTCP connection is established. If the peer did not announce any additional addresses using the MPTCP ADD_ADDR sub-option, this will behave the same as a plain **subflow **end‐ point. When the peer does announce addresses, each received ADD_ADDR sub-option will trigger creation of an additional subflow to generate a full mesh topology. The **limits **object specifies the constraints for subflow creations: ip mptcp limits show get current MPTCP subflow creation limits ip mptcp limits set change the MPTCP subflow creation limits _SUBFLOW_NR_ specifies the maximum number of additional subflows allowed for each MPTCP connection. Additional subflows can be created due to: incoming accepted ADD_ADDR sub-option, lo‐ cal **subflow **endpoints, additional subflows started by the peer. _ADD_ADDR_ACCEPTED_NR_ specifies the maximum number of incoming ADD_ADDR sub-options accepted for each MPTCP connection. After receiving the specified number of ADD_ADDR sub-options, any other incoming one will be ignored for the MPTCP connection lifetime. When an ADD_ADDR sub- option is accepted and there are no local _fullmesh_ endpoints, the MPTCP path manager will try to create a new subflow using the address in the ADD_ADDR sub-option as the destination address and a source address determined using local routing resolution When _fullmesh_ endpoints are available, the MPTCP path manager will try to create new subflows using each _fullmesh_ endpoint as a source address and the peer's ADD_ADDR ad‐ dress as the destination. In both cases the _SUBFLOW_NR_ limit is enforced. **monitor **displays creation and deletion of MPTCP connections as well as addition or removal of remote addresses and subflows. ## AUTHOR Original Manpage by Paolo Abeni <> iproute2 4 Apr 2020 [_IP-MPTCP_(8)](https://www.chedong.com/phpMan.php/man/IP-MPTCP/8/markdown)