Linux kernel mirror (for testing)
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1.. SPDX-License-Identifier: GPL-2.0
2
3=====================
4MPTCP Sysfs variables
5=====================
6
7/proc/sys/net/mptcp/* Variables
8===============================
9
10add_addr_timeout - INTEGER (seconds)
11 Set the maximum value of timeout after which an ADD_ADDR control message
12 will be resent to an MPTCP peer that has not acknowledged a previous
13 ADD_ADDR message. A dynamically estimated retransmission timeout based
14 on the estimated connection round-trip-time is used if this value is
15 lower than the maximum one.
16
17 Do not retransmit if set to 0.
18
19 The default value matches TCP_RTO_MAX. This is a per-namespace
20 sysctl.
21
22 Default: 120
23
24allow_join_initial_addr_port - BOOLEAN
25 Allow peers to send join requests to the IP address and port number used
26 by the initial subflow if the value is 1. This controls a flag that is
27 sent to the peer at connection time, and whether such join requests are
28 accepted or denied.
29
30 Joins to addresses advertised with ADD_ADDR are not affected by this
31 value.
32
33 This is a per-namespace sysctl.
34
35 Default: 1
36
37available_path_managers - STRING
38 Shows the available path managers choices that are registered. More
39 path managers may be available, but not loaded.
40
41available_schedulers - STRING
42 Shows the available schedulers choices that are registered. More packet
43 schedulers may be available, but not loaded.
44
45blackhole_timeout - INTEGER (seconds)
46 Initial time period in second to disable MPTCP on active MPTCP sockets
47 when a MPTCP firewall blackhole issue happens. This time period will
48 grow exponentially when more blackhole issues get detected right after
49 MPTCP is re-enabled and will reset to the initial value when the
50 blackhole issue goes away.
51
52 0 to disable the blackhole detection. This is a per-namespace sysctl.
53
54 Default: 3600
55
56checksum_enabled - BOOLEAN
57 Control whether DSS checksum can be enabled.
58
59 DSS checksum can be enabled if the value is nonzero. This is a
60 per-namespace sysctl.
61
62 Default: 0
63
64close_timeout - INTEGER (seconds)
65 Set the make-after-break timeout: in absence of any close or
66 shutdown syscall, MPTCP sockets will maintain the status
67 unchanged for such time, after the last subflow removal, before
68 moving to TCP_CLOSE.
69
70 The default value matches TCP_TIMEWAIT_LEN. This is a per-namespace
71 sysctl.
72
73 Default: 60
74
75enabled - BOOLEAN
76 Control whether MPTCP sockets can be created.
77
78 MPTCP sockets can be created if the value is 1. This is a
79 per-namespace sysctl.
80
81 Default: 1 (enabled)
82
83path_manager - STRING
84 Set the default path manager name to use for each new MPTCP
85 socket. In-kernel path management will control subflow
86 connections and address advertisements according to
87 per-namespace values configured over the MPTCP netlink
88 API. Userspace path management puts per-MPTCP-connection subflow
89 connection decisions and address advertisements under control of
90 a privileged userspace program, at the cost of more netlink
91 traffic to propagate all of the related events and commands.
92
93 This is a per-namespace sysctl.
94
95 * "kernel" - In-kernel path manager
96 * "userspace" - Userspace path manager
97
98 Default: "kernel"
99
100pm_type - INTEGER
101 Set the default path manager type to use for each new MPTCP
102 socket. In-kernel path management will control subflow
103 connections and address advertisements according to
104 per-namespace values configured over the MPTCP netlink
105 API. Userspace path management puts per-MPTCP-connection subflow
106 connection decisions and address advertisements under control of
107 a privileged userspace program, at the cost of more netlink
108 traffic to propagate all of the related events and commands.
109
110 This is a per-namespace sysctl.
111
112 Deprecated since v6.15, use path_manager instead.
113
114 * 0 - In-kernel path manager
115 * 1 - Userspace path manager
116
117 Default: 0
118
119scheduler - STRING
120 Select the scheduler of your choice.
121
122 Support for selection of different schedulers. This is a per-namespace
123 sysctl.
124
125 Default: "default"
126
127stale_loss_cnt - INTEGER
128 The number of MPTCP-level retransmission intervals with no traffic and
129 pending outstanding data on a given subflow required to declare it stale.
130 The packet scheduler ignores stale subflows.
131 A low stale_loss_cnt value allows for fast active-backup switch-over,
132 an high value maximize links utilization on edge scenarios e.g. lossy
133 link with high BER or peer pausing the data processing.
134
135 This is a per-namespace sysctl.
136
137 Default: 4
138
139syn_retrans_before_tcp_fallback - INTEGER
140 The number of SYN + MP_CAPABLE retransmissions before falling back to
141 TCP, i.e. dropping the MPTCP options. In other words, if all the packets
142 are dropped on the way, there will be:
143
144 * The initial SYN with MPTCP support
145 * This number of SYN retransmitted with MPTCP support
146 * The next SYN retransmissions will be without MPTCP support
147
148 0 means the first retransmission will be done without MPTCP options.
149 >= 128 means that all SYN retransmissions will keep the MPTCP options. A
150 lower number might increase false-positive MPTCP blackholes detections.
151 This is a per-namespace sysctl.
152
153 Default: 2