Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) ================================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) Documentation for /proc/sys/net/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3) ================================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5) Copyright
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7) Copyright (c) 1999
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9) 	- Terrehon Bowden <terrehon@pacbell.net>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10) 	- Bodo Bauer <bb@ricochet.net>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) Copyright (c) 2000
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) 	- Jorge Nerin <comandante@zaralinux.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) Copyright (c) 2009
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) 	- Shen Feng <shen@cn.fujitsu.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) For general info and legal blurb, please look in index.rst.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) ------------------------------------------------------------------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) This file contains the documentation for the sysctl files in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) /proc/sys/net
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) The interface  to  the  networking  parts  of  the  kernel  is  located  in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) /proc/sys/net. The following table shows all possible subdirectories.  You may
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) see only some of them, depending on your kernel's configuration.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) Table : Subdirectories in /proc/sys/net
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34)  ========= =================== = ========== ==================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35)  Directory Content               Directory  Content
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36)  ========= =================== = ========== ==================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37)  core      General parameter     appletalk  Appletalk protocol
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38)  unix      Unix domain sockets   netrom     NET/ROM
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39)  802       E802 protocol         ax25       AX25
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40)  ethernet  Ethernet protocol     rose       X.25 PLP layer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41)  ipv4      IP version 4          x25        X.25 protocol
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42)  bridge    Bridging              decnet     DEC net
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43)  ipv6      IP version 6          tipc       TIPC
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44)  ========= =================== = ========== ==================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 1. /proc/sys/net/core - Network core options
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) ============================================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) bpf_jit_enable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) --------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) This enables the BPF Just in Time (JIT) compiler. BPF is a flexible
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) and efficient infrastructure allowing to execute bytecode at various
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) hook points. It is used in a number of Linux kernel subsystems such
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) as networking (e.g. XDP, tc), tracing (e.g. kprobes, uprobes, tracepoints)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) and security (e.g. seccomp). LLVM has a BPF back end that can compile
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) restricted C into a sequence of BPF instructions. After program load
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) through bpf(2) and passing a verifier in the kernel, a JIT will then
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) translate these BPF proglets into native CPU instructions. There are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) two flavors of JITs, the newer eBPF JIT currently supported on:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62)   - x86_64
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63)   - x86_32
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64)   - arm64
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65)   - arm32
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66)   - ppc64
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67)   - sparc64
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68)   - mips64
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69)   - s390x
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70)   - riscv64
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71)   - riscv32
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) And the older cBPF JIT supported on the following archs:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75)   - mips
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76)   - ppc
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77)   - sparc
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) eBPF JITs are a superset of cBPF JITs, meaning the kernel will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) migrate cBPF instructions into eBPF instructions and then JIT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) compile them transparently. Older cBPF JITs can only translate
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) tcpdump filters, seccomp rules, etc, but not mentioned eBPF
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) programs loaded through bpf(2).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) Values:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 	- 0 - disable the JIT (default value)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 	- 1 - enable the JIT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 	- 2 - enable the JIT and ask the compiler to emit traces on kernel log.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) bpf_jit_harden
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) --------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) This enables hardening for the BPF JIT compiler. Supported are eBPF
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) JIT backends. Enabling hardening trades off performance, but can
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) mitigate JIT spraying.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) Values:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 	- 0 - disable JIT hardening (default value)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 	- 1 - enable JIT hardening for unprivileged users only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 	- 2 - enable JIT hardening for all users
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) bpf_jit_kallsyms
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) ----------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) When BPF JIT compiler is enabled, then compiled images are unknown
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) addresses to the kernel, meaning they neither show up in traces nor
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) in /proc/kallsyms. This enables export of these addresses, which can
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) be used for debugging/tracing. If bpf_jit_harden is enabled, this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) feature is disabled.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) Values :
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) 	- 0 - disable JIT kallsyms export (default value)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 	- 1 - enable JIT kallsyms export for privileged users only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) bpf_jit_limit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) -------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) This enforces a global limit for memory allocations to the BPF JIT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) compiler in order to reject unprivileged JIT requests once it has
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) been surpassed. bpf_jit_limit contains the value of the global limit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) in bytes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) dev_weight
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) ----------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) The maximum number of packets that kernel can handle on a NAPI interrupt,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) it's a Per-CPU variable. For drivers that support LRO or GRO_HW, a hardware
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) aggregated packet is counted as one packet in this context.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) Default: 64
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) dev_weight_rx_bias
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) ------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) RPS (e.g. RFS, aRFS) processing is competing with the registered NAPI poll function
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) of the driver for the per softirq cycle netdev_budget. This parameter influences
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) the proportion of the configured netdev_budget that is spent on RPS based packet
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) processing during RX softirq cycles. It is further meant for making current
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) dev_weight adaptable for asymmetric CPU needs on RX/TX side of the network stack.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) (see dev_weight_tx_bias) It is effective on a per CPU basis. Determination is based
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) on dev_weight and is calculated multiplicative (dev_weight * dev_weight_rx_bias).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) Default: 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) dev_weight_tx_bias
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) ------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) Scales the maximum number of packets that can be processed during a TX softirq cycle.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) Effective on a per CPU basis. Allows scaling of current dev_weight for asymmetric
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) net stack processing needs. Be careful to avoid making TX softirq processing a CPU hog.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) Calculation is based on dev_weight (dev_weight * dev_weight_tx_bias).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) Default: 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) default_qdisc
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) -------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) The default queuing discipline to use for network devices. This allows
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) overriding the default of pfifo_fast with an alternative. Since the default
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) queuing discipline is created without additional parameters so is best suited
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) to queuing disciplines that work well without configuration like stochastic
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) fair queue (sfq), CoDel (codel) or fair queue CoDel (fq_codel). Don't use
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) queuing disciplines like Hierarchical Token Bucket or Deficit Round Robin
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) which require setting up classes and bandwidths. Note that physical multiqueue
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) interfaces still use mq as root qdisc, which in turn uses this default for its
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) leaves. Virtual devices (like e.g. lo or veth) ignore this setting and instead
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) default to noqueue.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) Default: pfifo_fast
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) busy_read
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) ---------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) Low latency busy poll timeout for socket reads. (needs CONFIG_NET_RX_BUSY_POLL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) Approximate time in us to busy loop waiting for packets on the device queue.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) This sets the default value of the SO_BUSY_POLL socket option.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) Can be set or overridden per socket by setting socket option SO_BUSY_POLL,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) which is the preferred method of enabling. If you need to enable the feature
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) globally via sysctl, a value of 50 is recommended.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) Will increase power usage.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) Default: 0 (off)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) busy_poll
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) ----------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) Low latency busy poll timeout for poll and select. (needs CONFIG_NET_RX_BUSY_POLL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) Approximate time in us to busy loop waiting for events.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) Recommended value depends on the number of sockets you poll on.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) For several sockets 50, for several hundreds 100.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) For more than that you probably want to use epoll.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) Note that only sockets with SO_BUSY_POLL set will be busy polled,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) so you want to either selectively set SO_BUSY_POLL on those sockets or set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) sysctl.net.busy_read globally.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) Will increase power usage.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) Default: 0 (off)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) rmem_default
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) ------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) The default setting of the socket receive buffer in bytes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) rmem_max
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) --------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) The maximum receive socket buffer size in bytes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) tstamp_allow_data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) -----------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) Allow processes to receive tx timestamps looped together with the original
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) packet contents. If disabled, transmit timestamp requests from unprivileged
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) processes are dropped unless socket option SOF_TIMESTAMPING_OPT_TSONLY is set.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) Default: 1 (on)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) wmem_default
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) ------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) The default setting (in bytes) of the socket send buffer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) wmem_max
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) --------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) The maximum send socket buffer size in bytes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) message_burst and message_cost
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) ------------------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) These parameters  are used to limit the warning messages written to the kernel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) log from  the  networking  code.  They  enforce  a  rate  limit  to  make  a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) denial-of-service attack  impossible. A higher message_cost factor, results in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) fewer messages that will be written. Message_burst controls when messages will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) be dropped.  The  default  settings  limit  warning messages to one every five
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) seconds.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) warnings
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) --------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) This sysctl is now unused.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) This was used to control console messages from the networking stack that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) occur because of problems on the network like duplicate address or bad
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) checksums.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) These messages are now emitted at KERN_DEBUG and can generally be enabled
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) and controlled by the dynamic_debug facility.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) netdev_budget
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) -------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) Maximum number of packets taken from all interfaces in one polling cycle (NAPI
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) poll). In one polling cycle interfaces which are registered to polling are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) probed in a round-robin manner. Also, a polling cycle may not exceed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) netdev_budget_usecs microseconds, even if netdev_budget has not been
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) exhausted.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) netdev_budget_usecs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) ---------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) Maximum number of microseconds in one NAPI polling cycle. Polling
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) will exit when either netdev_budget_usecs have elapsed during the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) poll cycle or the number of packets processed reaches netdev_budget.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) netdev_max_backlog
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) ------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) Maximum number  of  packets,  queued  on  the  INPUT  side, when the interface
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) receives packets faster than kernel can process them.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) netdev_rss_key
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) --------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) RSS (Receive Side Scaling) enabled drivers use a 40 bytes host key that is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) randomly generated.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) Some user space might need to gather its content even if drivers do not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) provide ethtool -x support yet.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) ::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287)   myhost:~# cat /proc/sys/net/core/netdev_rss_key
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288)   84:50:f4:00:a8:15:d1:a7:e9:7f:1d:60:35:c7:47:25:42:97:74:ca:56:bb:b6:a1:d8: ... (52 bytes total)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) File contains nul bytes if no driver ever called netdev_rss_key_fill() function.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) Note:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293)   /proc/sys/net/core/netdev_rss_key contains 52 bytes of key,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294)   but most drivers only use 40 bytes of it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) ::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298)   myhost:~# ethtool -x eth0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299)   RX flow hash indirection table for eth0 with 8 RX ring(s):
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300)       0:    0     1     2     3     4     5     6     7
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301)   RSS hash key:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302)   84:50:f4:00:a8:15:d1:a7:e9:7f:1d:60:35:c7:47:25:42:97:74:ca:56:bb:b6:a1:d8:43:e3:c9:0c:fd:17:55:c2:3a:4d:69:ed:f1:42:89
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) netdev_tstamp_prequeue
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) ----------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) If set to 0, RX packet timestamps can be sampled after RPS processing, when
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) the target CPU processes packets. It might give some delay on timestamps, but
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) permit to distribute the load on several cpus.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) If set to 1 (default), timestamps are sampled as soon as possible, before
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) queueing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) optmem_max
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) ----------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) Maximum ancillary buffer size allowed per socket. Ancillary data is a sequence
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) of struct cmsghdr structures with appended data.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) fb_tunnels_only_for_init_net
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) ----------------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) Controls if fallback tunnels (like tunl0, gre0, gretap0, erspan0,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) sit0, ip6tnl0, ip6gre0) are automatically created. There are 3 possibilities
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) (a) value = 0; respective fallback tunnels are created when module is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) loaded in every net namespaces (backward compatible behavior).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) (b) value = 1; [kcmd value: initns] respective fallback tunnels are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) created only in init net namespace and every other net namespace will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) not have them.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) (c) value = 2; [kcmd value: none] fallback tunnels are not created
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) when a module is loaded in any of the net namespace. Setting value to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) "2" is pointless after boot if these modules are built-in, so there is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) a kernel command-line option that can change this default. Please refer to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) Documentation/admin-guide/kernel-parameters.txt for additional details.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) Not creating fallback tunnels gives control to userspace to create
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) whatever is needed only and avoid creating devices which are redundant.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) Default : 0  (for compatibility reasons)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) devconf_inherit_init_net
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) ------------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) Controls if a new network namespace should inherit all current
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) settings under /proc/sys/net/{ipv4,ipv6}/conf/{all,default}/. By
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) default, we keep the current behavior: for IPv4 we inherit all current
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) settings from init_net and for IPv6 we reset all settings to default.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) If set to 1, both IPv4 and IPv6 settings are forced to inherit from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) current ones in init_net. If set to 2, both IPv4 and IPv6 settings are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) forced to reset to their default values. If set to 3, both IPv4 and IPv6
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) settings are forced to inherit from current ones in the netns where this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) new netns has been created.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) Default : 0  (for compatibility reasons)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) 2. /proc/sys/net/unix - Parameters for Unix domain sockets
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) ----------------------------------------------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) There is only one file in this directory.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) unix_dgram_qlen limits the max number of datagrams queued in Unix domain
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) socket's buffer. It will not take effect unless PF_UNIX flag is specified.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) 3. /proc/sys/net/ipv4 - IPV4 settings
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) -------------------------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) Please see: Documentation/networking/ip-sysctl.rst and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) Documentation/admin-guide/sysctl/net.rst for descriptions of these entries.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) 4. Appletalk
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) ------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) The /proc/sys/net/appletalk  directory  holds the Appletalk configuration data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) when Appletalk is loaded. The configurable parameters are:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) aarp-expiry-time
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) ----------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) The amount  of  time  we keep an ARP entry before expiring it. Used to age out
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) old hosts.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) aarp-resolve-time
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) -----------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) The amount of time we will spend trying to resolve an Appletalk address.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) aarp-retransmit-limit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) ---------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) The number of times we will retransmit a query before giving up.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) aarp-tick-time
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) --------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) Controls the rate at which expires are checked.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) The directory  /proc/net/appletalk  holds the list of active Appletalk sockets
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) on a machine.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) The fields  indicate  the DDP type, the local address (in network:node format)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) the remote  address,  the  size of the transmit pending queue, the size of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) received queue  (bytes waiting for applications to read) the state and the uid
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) owning the socket.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) /proc/net/atalk_iface lists  all  the  interfaces  configured for appletalk.It
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) shows the  name  of the interface, its Appletalk address, the network range on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) that address  (or  network number for phase 1 networks), and the status of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) interface.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) /proc/net/atalk_route lists  each  known  network  route.  It lists the target
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) (network) that the route leads to, the router (may be directly connected), the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) route flags, and the device the route is using.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) 5. TIPC
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416) -------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) tipc_rmem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) ---------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) The TIPC protocol now has a tunable for the receive memory, similar to the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) tcp_rmem - i.e. a vector of 3 INTEGERs: (min, default, max)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424) ::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426)     # cat /proc/sys/net/tipc/tipc_rmem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427)     4252725 34021800        68043600
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428)     #
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) The max value is set to CONN_OVERLOAD_LIMIT, and the default and min values
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) are scaled (shifted) versions of that same value.  Note that the min value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) is not at this point in time used in any meaningful way, but the triplet is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433) preserved in order to be consistent with things like tcp_rmem.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435) named_timeout
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) -------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) TIPC name table updates are distributed asynchronously in a cluster, without
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439) any form of transaction handling. This means that different race scenarios are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440) possible. One such is that a name withdrawal sent out by one node and received
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) by another node may arrive after a second, overlapping name publication already
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442) has been accepted from a third node, although the conflicting updates
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) originally may have been issued in the correct sequential order.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) If named_timeout is nonzero, failed topology updates will be placed on a defer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) queue until another event arrives that clears the error, or until the timeout
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446) expires. Value is in milliseconds.