255 строки
9.1 KiB
Plaintext
255 строки
9.1 KiB
Plaintext
Documentation for /proc/sys/net/*
|
|
(c) 1999 Terrehon Bowden <terrehon@pacbell.net>
|
|
Bodo Bauer <bb@ricochet.net>
|
|
(c) 2000 Jorge Nerin <comandante@zaralinux.com>
|
|
(c) 2009 Shen Feng <shen@cn.fujitsu.com>
|
|
|
|
For general info and legal blurb, please look in README.
|
|
|
|
==============================================================
|
|
|
|
This file contains the documentation for the sysctl files in
|
|
/proc/sys/net
|
|
|
|
The interface to the networking parts of the kernel is located in
|
|
/proc/sys/net. The following table shows all possible subdirectories. You may
|
|
see only some of them, depending on your kernel's configuration.
|
|
|
|
|
|
Table : Subdirectories in /proc/sys/net
|
|
..............................................................................
|
|
Directory Content Directory Content
|
|
core General parameter appletalk Appletalk protocol
|
|
unix Unix domain sockets netrom NET/ROM
|
|
802 E802 protocol ax25 AX25
|
|
ethernet Ethernet protocol rose X.25 PLP layer
|
|
ipv4 IP version 4 x25 X.25 protocol
|
|
ipx IPX token-ring IBM token ring
|
|
bridge Bridging decnet DEC net
|
|
ipv6 IP version 6 tipc TIPC
|
|
..............................................................................
|
|
|
|
1. /proc/sys/net/core - Network core options
|
|
-------------------------------------------------------
|
|
|
|
bpf_jit_enable
|
|
--------------
|
|
|
|
This enables Berkeley Packet Filter Just in Time compiler.
|
|
Currently supported on x86_64 architecture, bpf_jit provides a framework
|
|
to speed packet filtering, the one used by tcpdump/libpcap for example.
|
|
Values :
|
|
0 - disable the JIT (default value)
|
|
1 - enable the JIT
|
|
2 - enable the JIT and ask the compiler to emit traces on kernel log.
|
|
|
|
dev_weight
|
|
--------------
|
|
|
|
The maximum number of packets that kernel can handle on a NAPI interrupt,
|
|
it's a Per-CPU variable.
|
|
Default: 64
|
|
|
|
default_qdisc
|
|
--------------
|
|
|
|
The default queuing discipline to use for network devices. This allows
|
|
overriding the default queue discipline of pfifo_fast with an
|
|
alternative. Since the default queuing discipline is created with the
|
|
no additional parameters so is best suited to queuing disciplines that
|
|
work well without configuration like stochastic fair queue (sfq),
|
|
CoDel (codel) or fair queue CoDel (fq_codel). Don't use queuing disciplines
|
|
like Hierarchical Token Bucket or Deficit Round Robin which require setting
|
|
up classes and bandwidths.
|
|
Default: pfifo_fast
|
|
|
|
busy_read
|
|
----------------
|
|
Low latency busy poll timeout for socket reads. (needs CONFIG_NET_RX_BUSY_POLL)
|
|
Approximate time in us to busy loop waiting for packets on the device queue.
|
|
This sets the default value of the SO_BUSY_POLL socket option.
|
|
Can be set or overridden per socket by setting socket option SO_BUSY_POLL,
|
|
which is the preferred method of enabling. If you need to enable the feature
|
|
globally via sysctl, a value of 50 is recommended.
|
|
Will increase power usage.
|
|
Default: 0 (off)
|
|
|
|
busy_poll
|
|
----------------
|
|
Low latency busy poll timeout for poll and select. (needs CONFIG_NET_RX_BUSY_POLL)
|
|
Approximate time in us to busy loop waiting for events.
|
|
Recommended value depends on the number of sockets you poll on.
|
|
For several sockets 50, for several hundreds 100.
|
|
For more than that you probably want to use epoll.
|
|
Note that only sockets with SO_BUSY_POLL set will be busy polled,
|
|
so you want to either selectively set SO_BUSY_POLL on those sockets or set
|
|
sysctl.net.busy_read globally.
|
|
Will increase power usage.
|
|
Default: 0 (off)
|
|
|
|
rmem_default
|
|
------------
|
|
|
|
The default setting of the socket receive buffer in bytes.
|
|
|
|
rmem_max
|
|
--------
|
|
|
|
The maximum receive socket buffer size in bytes.
|
|
|
|
wmem_default
|
|
------------
|
|
|
|
The default setting (in bytes) of the socket send buffer.
|
|
|
|
wmem_max
|
|
--------
|
|
|
|
The maximum send socket buffer size in bytes.
|
|
|
|
message_burst and message_cost
|
|
------------------------------
|
|
|
|
These parameters are used to limit the warning messages written to the kernel
|
|
log from the networking code. They enforce a rate limit to make a
|
|
denial-of-service attack impossible. A higher message_cost factor, results in
|
|
fewer messages that will be written. Message_burst controls when messages will
|
|
be dropped. The default settings limit warning messages to one every five
|
|
seconds.
|
|
|
|
warnings
|
|
--------
|
|
|
|
This controls console messages from the networking stack that can occur because
|
|
of problems on the network like duplicate address or bad checksums. Normally,
|
|
this should be enabled, but if the problem persists the messages can be
|
|
disabled.
|
|
|
|
netdev_budget
|
|
-------------
|
|
|
|
Maximum number of packets taken from all interfaces in one polling cycle (NAPI
|
|
poll). In one polling cycle interfaces which are registered to polling are
|
|
probed in a round-robin manner.
|
|
|
|
netdev_max_backlog
|
|
------------------
|
|
|
|
Maximum number of packets, queued on the INPUT side, when the interface
|
|
receives packets faster than kernel can process them.
|
|
|
|
netdev_tstamp_prequeue
|
|
----------------------
|
|
|
|
If set to 0, RX packet timestamps can be sampled after RPS processing, when
|
|
the target CPU processes packets. It might give some delay on timestamps, but
|
|
permit to distribute the load on several cpus.
|
|
|
|
If set to 1 (default), timestamps are sampled as soon as possible, before
|
|
queueing.
|
|
|
|
optmem_max
|
|
----------
|
|
|
|
Maximum ancillary buffer size allowed per socket. Ancillary data is a sequence
|
|
of struct cmsghdr structures with appended data.
|
|
|
|
2. /proc/sys/net/unix - Parameters for Unix domain sockets
|
|
-------------------------------------------------------
|
|
|
|
There is only one file in this directory.
|
|
unix_dgram_qlen limits the max number of datagrams queued in Unix domain
|
|
socket's buffer. It will not take effect unless PF_UNIX flag is specified.
|
|
|
|
|
|
3. /proc/sys/net/ipv4 - IPV4 settings
|
|
-------------------------------------------------------
|
|
Please see: Documentation/networking/ip-sysctl.txt and ipvs-sysctl.txt for
|
|
descriptions of these entries.
|
|
|
|
|
|
4. Appletalk
|
|
-------------------------------------------------------
|
|
|
|
The /proc/sys/net/appletalk directory holds the Appletalk configuration data
|
|
when Appletalk is loaded. The configurable parameters are:
|
|
|
|
aarp-expiry-time
|
|
----------------
|
|
|
|
The amount of time we keep an ARP entry before expiring it. Used to age out
|
|
old hosts.
|
|
|
|
aarp-resolve-time
|
|
-----------------
|
|
|
|
The amount of time we will spend trying to resolve an Appletalk address.
|
|
|
|
aarp-retransmit-limit
|
|
---------------------
|
|
|
|
The number of times we will retransmit a query before giving up.
|
|
|
|
aarp-tick-time
|
|
--------------
|
|
|
|
Controls the rate at which expires are checked.
|
|
|
|
The directory /proc/net/appletalk holds the list of active Appletalk sockets
|
|
on a machine.
|
|
|
|
The fields indicate the DDP type, the local address (in network:node format)
|
|
the remote address, the size of the transmit pending queue, the size of the
|
|
received queue (bytes waiting for applications to read) the state and the uid
|
|
owning the socket.
|
|
|
|
/proc/net/atalk_iface lists all the interfaces configured for appletalk.It
|
|
shows the name of the interface, its Appletalk address, the network range on
|
|
that address (or network number for phase 1 networks), and the status of the
|
|
interface.
|
|
|
|
/proc/net/atalk_route lists each known network route. It lists the target
|
|
(network) that the route leads to, the router (may be directly connected), the
|
|
route flags, and the device the route is using.
|
|
|
|
|
|
5. IPX
|
|
-------------------------------------------------------
|
|
|
|
The IPX protocol has no tunable values in proc/sys/net.
|
|
|
|
The IPX protocol does, however, provide proc/net/ipx. This lists each IPX
|
|
socket giving the local and remote addresses in Novell format (that is
|
|
network:node:port). In accordance with the strange Novell tradition,
|
|
everything but the port is in hex. Not_Connected is displayed for sockets that
|
|
are not tied to a specific remote address. The Tx and Rx queue sizes indicate
|
|
the number of bytes pending for transmission and reception. The state
|
|
indicates the state the socket is in and the uid is the owning uid of the
|
|
socket.
|
|
|
|
The /proc/net/ipx_interface file lists all IPX interfaces. For each interface
|
|
it gives the network number, the node number, and indicates if the network is
|
|
the primary network. It also indicates which device it is bound to (or
|
|
Internal for internal networks) and the Frame Type if appropriate. Linux
|
|
supports 802.3, 802.2, 802.2 SNAP and DIX (Blue Book) ethernet framing for
|
|
IPX.
|
|
|
|
The /proc/net/ipx_route table holds a list of IPX routes. For each route it
|
|
gives the destination network, the router node (or Directly) and the network
|
|
address of the router (or Connected) for internal networks.
|
|
|
|
6. TIPC
|
|
-------------------------------------------------------
|
|
|
|
The TIPC protocol now has a tunable for the receive memory, similar to the
|
|
tcp_rmem - i.e. a vector of 3 INTEGERs: (min, default, max)
|
|
|
|
# cat /proc/sys/net/tipc/tipc_rmem
|
|
4252725 34021800 68043600
|
|
#
|
|
|
|
The max value is set to CONN_OVERLOAD_LIMIT, and the default and min values
|
|
are scaled (shifted) versions of that same value. Note that the min value
|
|
is not at this point in time used in any meaningful way, but the triplet is
|
|
preserved in order to be consistent with things like tcp_rmem.
|