1371 строка
47 KiB
Plaintext
1371 строка
47 KiB
Plaintext
/proc/sys/net/ipv4/* Variables:
|
|
|
|
ip_forward - BOOLEAN
|
|
0 - disabled (default)
|
|
not 0 - enabled
|
|
|
|
Forward Packets between interfaces.
|
|
|
|
This variable is special, its change resets all configuration
|
|
parameters to their default state (RFC1122 for hosts, RFC1812
|
|
for routers)
|
|
|
|
ip_default_ttl - INTEGER
|
|
default 64
|
|
|
|
ip_no_pmtu_disc - BOOLEAN
|
|
Disable Path MTU Discovery.
|
|
default FALSE
|
|
|
|
min_pmtu - INTEGER
|
|
default 562 - minimum discovered Path MTU
|
|
|
|
mtu_expires - INTEGER
|
|
Time, in seconds, that cached PMTU information is kept.
|
|
|
|
min_adv_mss - INTEGER
|
|
The advertised MSS depends on the first hop route MTU, but will
|
|
never be lower than this setting.
|
|
|
|
rt_cache_rebuild_count - INTEGER
|
|
The per net-namespace route cache emergency rebuild threshold.
|
|
Any net-namespace having its route cache rebuilt due to
|
|
a hash bucket chain being too long more than this many times
|
|
will have its route caching disabled
|
|
|
|
IP Fragmentation:
|
|
|
|
ipfrag_high_thresh - INTEGER
|
|
Maximum memory used to reassemble IP fragments. When
|
|
ipfrag_high_thresh bytes of memory is allocated for this purpose,
|
|
the fragment handler will toss packets until ipfrag_low_thresh
|
|
is reached.
|
|
|
|
ipfrag_low_thresh - INTEGER
|
|
See ipfrag_high_thresh
|
|
|
|
ipfrag_time - INTEGER
|
|
Time in seconds to keep an IP fragment in memory.
|
|
|
|
ipfrag_secret_interval - INTEGER
|
|
Regeneration interval (in seconds) of the hash secret (or lifetime
|
|
for the hash secret) for IP fragments.
|
|
Default: 600
|
|
|
|
ipfrag_max_dist - INTEGER
|
|
ipfrag_max_dist is a non-negative integer value which defines the
|
|
maximum "disorder" which is allowed among fragments which share a
|
|
common IP source address. Note that reordering of packets is
|
|
not unusual, but if a large number of fragments arrive from a source
|
|
IP address while a particular fragment queue remains incomplete, it
|
|
probably indicates that one or more fragments belonging to that queue
|
|
have been lost. When ipfrag_max_dist is positive, an additional check
|
|
is done on fragments before they are added to a reassembly queue - if
|
|
ipfrag_max_dist (or more) fragments have arrived from a particular IP
|
|
address between additions to any IP fragment queue using that source
|
|
address, it's presumed that one or more fragments in the queue are
|
|
lost. The existing fragment queue will be dropped, and a new one
|
|
started. An ipfrag_max_dist value of zero disables this check.
|
|
|
|
Using a very small value, e.g. 1 or 2, for ipfrag_max_dist can
|
|
result in unnecessarily dropping fragment queues when normal
|
|
reordering of packets occurs, which could lead to poor application
|
|
performance. Using a very large value, e.g. 50000, increases the
|
|
likelihood of incorrectly reassembling IP fragments that originate
|
|
from different IP datagrams, which could result in data corruption.
|
|
Default: 64
|
|
|
|
INET peer storage:
|
|
|
|
inet_peer_threshold - INTEGER
|
|
The approximate size of the storage. Starting from this threshold
|
|
entries will be thrown aggressively. This threshold also determines
|
|
entries' time-to-live and time intervals between garbage collection
|
|
passes. More entries, less time-to-live, less GC interval.
|
|
|
|
inet_peer_minttl - INTEGER
|
|
Minimum time-to-live of entries. Should be enough to cover fragment
|
|
time-to-live on the reassembling side. This minimum time-to-live is
|
|
guaranteed if the pool size is less than inet_peer_threshold.
|
|
Measured in seconds.
|
|
|
|
inet_peer_maxttl - INTEGER
|
|
Maximum time-to-live of entries. Unused entries will expire after
|
|
this period of time if there is no memory pressure on the pool (i.e.
|
|
when the number of entries in the pool is very small).
|
|
Measured in seconds.
|
|
|
|
inet_peer_gc_mintime - INTEGER
|
|
Minimum interval between garbage collection passes. This interval is
|
|
in effect under high memory pressure on the pool.
|
|
Measured in seconds.
|
|
|
|
inet_peer_gc_maxtime - INTEGER
|
|
Minimum interval between garbage collection passes. This interval is
|
|
in effect under low (or absent) memory pressure on the pool.
|
|
Measured in seconds.
|
|
|
|
TCP variables:
|
|
|
|
somaxconn - INTEGER
|
|
Limit of socket listen() backlog, known in userspace as SOMAXCONN.
|
|
Defaults to 128. See also tcp_max_syn_backlog for additional tuning
|
|
for TCP sockets.
|
|
|
|
tcp_abc - INTEGER
|
|
Controls Appropriate Byte Count (ABC) defined in RFC3465.
|
|
ABC is a way of increasing congestion window (cwnd) more slowly
|
|
in response to partial acknowledgments.
|
|
Possible values are:
|
|
0 increase cwnd once per acknowledgment (no ABC)
|
|
1 increase cwnd once per acknowledgment of full sized segment
|
|
2 allow increase cwnd by two if acknowledgment is
|
|
of two segments to compensate for delayed acknowledgments.
|
|
Default: 0 (off)
|
|
|
|
tcp_abort_on_overflow - BOOLEAN
|
|
If listening service is too slow to accept new connections,
|
|
reset them. Default state is FALSE. It means that if overflow
|
|
occurred due to a burst, connection will recover. Enable this
|
|
option _only_ if you are really sure that listening daemon
|
|
cannot be tuned to accept connections faster. Enabling this
|
|
option can harm clients of your server.
|
|
|
|
tcp_adv_win_scale - INTEGER
|
|
Count buffering overhead as bytes/2^tcp_adv_win_scale
|
|
(if tcp_adv_win_scale > 0) or bytes-bytes/2^(-tcp_adv_win_scale),
|
|
if it is <= 0.
|
|
Default: 2
|
|
|
|
tcp_allowed_congestion_control - STRING
|
|
Show/set the congestion control choices available to non-privileged
|
|
processes. The list is a subset of those listed in
|
|
tcp_available_congestion_control.
|
|
Default is "reno" and the default setting (tcp_congestion_control).
|
|
|
|
tcp_app_win - INTEGER
|
|
Reserve max(window/2^tcp_app_win, mss) of window for application
|
|
buffer. Value 0 is special, it means that nothing is reserved.
|
|
Default: 31
|
|
|
|
tcp_available_congestion_control - STRING
|
|
Shows the available congestion control choices that are registered.
|
|
More congestion control algorithms may be available as modules,
|
|
but not loaded.
|
|
|
|
tcp_base_mss - INTEGER
|
|
The initial value of search_low to be used by the packetization layer
|
|
Path MTU discovery (MTU probing). If MTU probing is enabled,
|
|
this is the initial MSS used by the connection.
|
|
|
|
tcp_congestion_control - STRING
|
|
Set the congestion control algorithm to be used for new
|
|
connections. The algorithm "reno" is always available, but
|
|
additional choices may be available based on kernel configuration.
|
|
Default is set as part of kernel configuration.
|
|
|
|
tcp_cookie_size - INTEGER
|
|
Default size of TCP Cookie Transactions (TCPCT) option, that may be
|
|
overridden on a per socket basis by the TCPCT socket option.
|
|
Values greater than the maximum (16) are interpreted as the maximum.
|
|
Values greater than zero and less than the minimum (8) are interpreted
|
|
as the minimum. Odd values are interpreted as the next even value.
|
|
Default: 0 (off).
|
|
|
|
tcp_dsack - BOOLEAN
|
|
Allows TCP to send "duplicate" SACKs.
|
|
|
|
tcp_ecn - BOOLEAN
|
|
Enable Explicit Congestion Notification (ECN) in TCP. ECN is only
|
|
used when both ends of the TCP flow support it. It is useful to
|
|
avoid losses due to congestion (when the bottleneck router supports
|
|
ECN).
|
|
Possible values are:
|
|
0 disable ECN
|
|
1 ECN enabled
|
|
2 Only server-side ECN enabled. If the other end does
|
|
not support ECN, behavior is like with ECN disabled.
|
|
Default: 2
|
|
|
|
tcp_fack - BOOLEAN
|
|
Enable FACK congestion avoidance and fast retransmission.
|
|
The value is not used, if tcp_sack is not enabled.
|
|
|
|
tcp_fin_timeout - INTEGER
|
|
Time to hold socket in state FIN-WAIT-2, if it was closed
|
|
by our side. Peer can be broken and never close its side,
|
|
or even died unexpectedly. Default value is 60sec.
|
|
Usual value used in 2.2 was 180 seconds, you may restore
|
|
it, but remember that if your machine is even underloaded WEB server,
|
|
you risk to overflow memory with kilotons of dead sockets,
|
|
FIN-WAIT-2 sockets are less dangerous than FIN-WAIT-1,
|
|
because they eat maximum 1.5K of memory, but they tend
|
|
to live longer. Cf. tcp_max_orphans.
|
|
|
|
tcp_frto - INTEGER
|
|
Enables Forward RTO-Recovery (F-RTO) defined in RFC4138.
|
|
F-RTO is an enhanced recovery algorithm for TCP retransmission
|
|
timeouts. It is particularly beneficial in wireless environments
|
|
where packet loss is typically due to random radio interference
|
|
rather than intermediate router congestion. F-RTO is sender-side
|
|
only modification. Therefore it does not require any support from
|
|
the peer.
|
|
|
|
If set to 1, basic version is enabled. 2 enables SACK enhanced
|
|
F-RTO if flow uses SACK. The basic version can be used also when
|
|
SACK is in use though scenario(s) with it exists where F-RTO
|
|
interacts badly with the packet counting of the SACK enabled TCP
|
|
flow.
|
|
|
|
tcp_frto_response - INTEGER
|
|
When F-RTO has detected that a TCP retransmission timeout was
|
|
spurious (i.e, the timeout would have been avoided had TCP set a
|
|
longer retransmission timeout), TCP has several options what to do
|
|
next. Possible values are:
|
|
0 Rate halving based; a smooth and conservative response,
|
|
results in halved cwnd and ssthresh after one RTT
|
|
1 Very conservative response; not recommended because even
|
|
though being valid, it interacts poorly with the rest of
|
|
Linux TCP, halves cwnd and ssthresh immediately
|
|
2 Aggressive response; undoes congestion control measures
|
|
that are now known to be unnecessary (ignoring the
|
|
possibility of a lost retransmission that would require
|
|
TCP to be more cautious), cwnd and ssthresh are restored
|
|
to the values prior timeout
|
|
Default: 0 (rate halving based)
|
|
|
|
tcp_keepalive_time - INTEGER
|
|
How often TCP sends out keepalive messages when keepalive is enabled.
|
|
Default: 2hours.
|
|
|
|
tcp_keepalive_probes - INTEGER
|
|
How many keepalive probes TCP sends out, until it decides that the
|
|
connection is broken. Default value: 9.
|
|
|
|
tcp_keepalive_intvl - INTEGER
|
|
How frequently the probes are send out. Multiplied by
|
|
tcp_keepalive_probes it is time to kill not responding connection,
|
|
after probes started. Default value: 75sec i.e. connection
|
|
will be aborted after ~11 minutes of retries.
|
|
|
|
tcp_low_latency - BOOLEAN
|
|
If set, the TCP stack makes decisions that prefer lower
|
|
latency as opposed to higher throughput. By default, this
|
|
option is not set meaning that higher throughput is preferred.
|
|
An example of an application where this default should be
|
|
changed would be a Beowulf compute cluster.
|
|
Default: 0
|
|
|
|
tcp_max_orphans - INTEGER
|
|
Maximal number of TCP sockets not attached to any user file handle,
|
|
held by system. If this number is exceeded orphaned connections are
|
|
reset immediately and warning is printed. This limit exists
|
|
only to prevent simple DoS attacks, you _must_ not rely on this
|
|
or lower the limit artificially, but rather increase it
|
|
(probably, after increasing installed memory),
|
|
if network conditions require more than default value,
|
|
and tune network services to linger and kill such states
|
|
more aggressively. Let me to remind again: each orphan eats
|
|
up to ~64K of unswappable memory.
|
|
|
|
tcp_max_syn_backlog - INTEGER
|
|
Maximal number of remembered connection requests, which are
|
|
still did not receive an acknowledgment from connecting client.
|
|
Default value is 1024 for systems with more than 128Mb of memory,
|
|
and 128 for low memory machines. If server suffers of overload,
|
|
try to increase this number.
|
|
|
|
tcp_max_tw_buckets - INTEGER
|
|
Maximal number of timewait sockets held by system simultaneously.
|
|
If this number is exceeded time-wait socket is immediately destroyed
|
|
and warning is printed. This limit exists only to prevent
|
|
simple DoS attacks, you _must_ not lower the limit artificially,
|
|
but rather increase it (probably, after increasing installed memory),
|
|
if network conditions require more than default value.
|
|
|
|
tcp_mem - vector of 3 INTEGERs: min, pressure, max
|
|
min: below this number of pages TCP is not bothered about its
|
|
memory appetite.
|
|
|
|
pressure: when amount of memory allocated by TCP exceeds this number
|
|
of pages, TCP moderates its memory consumption and enters memory
|
|
pressure mode, which is exited when memory consumption falls
|
|
under "min".
|
|
|
|
max: number of pages allowed for queueing by all TCP sockets.
|
|
|
|
Defaults are calculated at boot time from amount of available
|
|
memory.
|
|
|
|
tcp_moderate_rcvbuf - BOOLEAN
|
|
If set, TCP performs receive buffer auto-tuning, attempting to
|
|
automatically size the buffer (no greater than tcp_rmem[2]) to
|
|
match the size required by the path for full throughput. Enabled by
|
|
default.
|
|
|
|
tcp_mtu_probing - INTEGER
|
|
Controls TCP Packetization-Layer Path MTU Discovery. Takes three
|
|
values:
|
|
0 - Disabled
|
|
1 - Disabled by default, enabled when an ICMP black hole detected
|
|
2 - Always enabled, use initial MSS of tcp_base_mss.
|
|
|
|
tcp_no_metrics_save - BOOLEAN
|
|
By default, TCP saves various connection metrics in the route cache
|
|
when the connection closes, so that connections established in the
|
|
near future can use these to set initial conditions. Usually, this
|
|
increases overall performance, but may sometimes cause performance
|
|
degradation. If set, TCP will not cache metrics on closing
|
|
connections.
|
|
|
|
tcp_orphan_retries - INTEGER
|
|
This value influences the timeout of a locally closed TCP connection,
|
|
when RTO retransmissions remain unacknowledged.
|
|
See tcp_retries2 for more details.
|
|
|
|
The default value is 7.
|
|
If your machine is a loaded WEB server,
|
|
you should think about lowering this value, such sockets
|
|
may consume significant resources. Cf. tcp_max_orphans.
|
|
|
|
tcp_reordering - INTEGER
|
|
Maximal reordering of packets in a TCP stream.
|
|
Default: 3
|
|
|
|
tcp_retrans_collapse - BOOLEAN
|
|
Bug-to-bug compatibility with some broken printers.
|
|
On retransmit try to send bigger packets to work around bugs in
|
|
certain TCP stacks.
|
|
|
|
tcp_retries1 - INTEGER
|
|
This value influences the time, after which TCP decides, that
|
|
something is wrong due to unacknowledged RTO retransmissions,
|
|
and reports this suspicion to the network layer.
|
|
See tcp_retries2 for more details.
|
|
|
|
RFC 1122 recommends at least 3 retransmissions, which is the
|
|
default.
|
|
|
|
tcp_retries2 - INTEGER
|
|
This value influences the timeout of an alive TCP connection,
|
|
when RTO retransmissions remain unacknowledged.
|
|
Given a value of N, a hypothetical TCP connection following
|
|
exponential backoff with an initial RTO of TCP_RTO_MIN would
|
|
retransmit N times before killing the connection at the (N+1)th RTO.
|
|
|
|
The default value of 15 yields a hypothetical timeout of 924.6
|
|
seconds and is a lower bound for the effective timeout.
|
|
TCP will effectively time out at the first RTO which exceeds the
|
|
hypothetical timeout.
|
|
|
|
RFC 1122 recommends at least 100 seconds for the timeout,
|
|
which corresponds to a value of at least 8.
|
|
|
|
tcp_rfc1337 - BOOLEAN
|
|
If set, the TCP stack behaves conforming to RFC1337. If unset,
|
|
we are not conforming to RFC, but prevent TCP TIME_WAIT
|
|
assassination.
|
|
Default: 0
|
|
|
|
tcp_rmem - vector of 3 INTEGERs: min, default, max
|
|
min: Minimal size of receive buffer used by TCP sockets.
|
|
It is guaranteed to each TCP socket, even under moderate memory
|
|
pressure.
|
|
Default: 8K
|
|
|
|
default: initial size of receive buffer used by TCP sockets.
|
|
This value overrides net.core.rmem_default used by other protocols.
|
|
Default: 87380 bytes. This value results in window of 65535 with
|
|
default setting of tcp_adv_win_scale and tcp_app_win:0 and a bit
|
|
less for default tcp_app_win. See below about these variables.
|
|
|
|
max: maximal size of receive buffer allowed for automatically
|
|
selected receiver buffers for TCP socket. This value does not override
|
|
net.core.rmem_max. Calling setsockopt() with SO_RCVBUF disables
|
|
automatic tuning of that socket's receive buffer size, in which
|
|
case this value is ignored.
|
|
Default: between 87380B and 4MB, depending on RAM size.
|
|
|
|
tcp_sack - BOOLEAN
|
|
Enable select acknowledgments (SACKS).
|
|
|
|
tcp_slow_start_after_idle - BOOLEAN
|
|
If set, provide RFC2861 behavior and time out the congestion
|
|
window after an idle period. An idle period is defined at
|
|
the current RTO. If unset, the congestion window will not
|
|
be timed out after an idle period.
|
|
Default: 1
|
|
|
|
tcp_stdurg - BOOLEAN
|
|
Use the Host requirements interpretation of the TCP urgent pointer field.
|
|
Most hosts use the older BSD interpretation, so if you turn this on
|
|
Linux might not communicate correctly with them.
|
|
Default: FALSE
|
|
|
|
tcp_synack_retries - INTEGER
|
|
Number of times SYNACKs for a passive TCP connection attempt will
|
|
be retransmitted. Should not be higher than 255. Default value
|
|
is 5, which corresponds to ~180seconds.
|
|
|
|
tcp_syncookies - BOOLEAN
|
|
Only valid when the kernel was compiled with CONFIG_SYNCOOKIES
|
|
Send out syncookies when the syn backlog queue of a socket
|
|
overflows. This is to prevent against the common 'SYN flood attack'
|
|
Default: FALSE
|
|
|
|
Note, that syncookies is fallback facility.
|
|
It MUST NOT be used to help highly loaded servers to stand
|
|
against legal connection rate. If you see SYN flood warnings
|
|
in your logs, but investigation shows that they occur
|
|
because of overload with legal connections, you should tune
|
|
another parameters until this warning disappear.
|
|
See: tcp_max_syn_backlog, tcp_synack_retries, tcp_abort_on_overflow.
|
|
|
|
syncookies seriously violate TCP protocol, do not allow
|
|
to use TCP extensions, can result in serious degradation
|
|
of some services (f.e. SMTP relaying), visible not by you,
|
|
but your clients and relays, contacting you. While you see
|
|
SYN flood warnings in logs not being really flooded, your server
|
|
is seriously misconfigured.
|
|
|
|
tcp_syn_retries - INTEGER
|
|
Number of times initial SYNs for an active TCP connection attempt
|
|
will be retransmitted. Should not be higher than 255. Default value
|
|
is 5, which corresponds to ~180seconds.
|
|
|
|
tcp_timestamps - BOOLEAN
|
|
Enable timestamps as defined in RFC1323.
|
|
|
|
tcp_tso_win_divisor - INTEGER
|
|
This allows control over what percentage of the congestion window
|
|
can be consumed by a single TSO frame.
|
|
The setting of this parameter is a choice between burstiness and
|
|
building larger TSO frames.
|
|
Default: 3
|
|
|
|
tcp_tw_recycle - BOOLEAN
|
|
Enable fast recycling TIME-WAIT sockets. Default value is 0.
|
|
It should not be changed without advice/request of technical
|
|
experts.
|
|
|
|
tcp_tw_reuse - BOOLEAN
|
|
Allow to reuse TIME-WAIT sockets for new connections when it is
|
|
safe from protocol viewpoint. Default value is 0.
|
|
It should not be changed without advice/request of technical
|
|
experts.
|
|
|
|
tcp_window_scaling - BOOLEAN
|
|
Enable window scaling as defined in RFC1323.
|
|
|
|
tcp_wmem - vector of 3 INTEGERs: min, default, max
|
|
min: Amount of memory reserved for send buffers for TCP sockets.
|
|
Each TCP socket has rights to use it due to fact of its birth.
|
|
Default: 4K
|
|
|
|
default: initial size of send buffer used by TCP sockets. This
|
|
value overrides net.core.wmem_default used by other protocols.
|
|
It is usually lower than net.core.wmem_default.
|
|
Default: 16K
|
|
|
|
max: Maximal amount of memory allowed for automatically tuned
|
|
send buffers for TCP sockets. This value does not override
|
|
net.core.wmem_max. Calling setsockopt() with SO_SNDBUF disables
|
|
automatic tuning of that socket's send buffer size, in which case
|
|
this value is ignored.
|
|
Default: between 64K and 4MB, depending on RAM size.
|
|
|
|
tcp_workaround_signed_windows - BOOLEAN
|
|
If set, assume no receipt of a window scaling option means the
|
|
remote TCP is broken and treats the window as a signed quantity.
|
|
If unset, assume the remote TCP is not broken even if we do
|
|
not receive a window scaling option from them.
|
|
Default: 0
|
|
|
|
tcp_dma_copybreak - INTEGER
|
|
Lower limit, in bytes, of the size of socket reads that will be
|
|
offloaded to a DMA copy engine, if one is present in the system
|
|
and CONFIG_NET_DMA is enabled.
|
|
Default: 4096
|
|
|
|
UDP variables:
|
|
|
|
udp_mem - vector of 3 INTEGERs: min, pressure, max
|
|
Number of pages allowed for queueing by all UDP sockets.
|
|
|
|
min: Below this number of pages UDP is not bothered about its
|
|
memory appetite. When amount of memory allocated by UDP exceeds
|
|
this number, UDP starts to moderate memory usage.
|
|
|
|
pressure: This value was introduced to follow format of tcp_mem.
|
|
|
|
max: Number of pages allowed for queueing by all UDP sockets.
|
|
|
|
Default is calculated at boot time from amount of available memory.
|
|
|
|
udp_rmem_min - INTEGER
|
|
Minimal size of receive buffer used by UDP sockets in moderation.
|
|
Each UDP socket is able to use the size for receiving data, even if
|
|
total pages of UDP sockets exceed udp_mem pressure. The unit is byte.
|
|
Default: 4096
|
|
|
|
udp_wmem_min - INTEGER
|
|
Minimal size of send buffer used by UDP sockets in moderation.
|
|
Each UDP socket is able to use the size for sending data, even if
|
|
total pages of UDP sockets exceed udp_mem pressure. The unit is byte.
|
|
Default: 4096
|
|
|
|
CIPSOv4 Variables:
|
|
|
|
cipso_cache_enable - BOOLEAN
|
|
If set, enable additions to and lookups from the CIPSO label mapping
|
|
cache. If unset, additions are ignored and lookups always result in a
|
|
miss. However, regardless of the setting the cache is still
|
|
invalidated when required when means you can safely toggle this on and
|
|
off and the cache will always be "safe".
|
|
Default: 1
|
|
|
|
cipso_cache_bucket_size - INTEGER
|
|
The CIPSO label cache consists of a fixed size hash table with each
|
|
hash bucket containing a number of cache entries. This variable limits
|
|
the number of entries in each hash bucket; the larger the value the
|
|
more CIPSO label mappings that can be cached. When the number of
|
|
entries in a given hash bucket reaches this limit adding new entries
|
|
causes the oldest entry in the bucket to be removed to make room.
|
|
Default: 10
|
|
|
|
cipso_rbm_optfmt - BOOLEAN
|
|
Enable the "Optimized Tag 1 Format" as defined in section 3.4.2.6 of
|
|
the CIPSO draft specification (see Documentation/netlabel for details).
|
|
This means that when set the CIPSO tag will be padded with empty
|
|
categories in order to make the packet data 32-bit aligned.
|
|
Default: 0
|
|
|
|
cipso_rbm_structvalid - BOOLEAN
|
|
If set, do a very strict check of the CIPSO option when
|
|
ip_options_compile() is called. If unset, relax the checks done during
|
|
ip_options_compile(). Either way is "safe" as errors are caught else
|
|
where in the CIPSO processing code but setting this to 0 (False) should
|
|
result in less work (i.e. it should be faster) but could cause problems
|
|
with other implementations that require strict checking.
|
|
Default: 0
|
|
|
|
IP Variables:
|
|
|
|
ip_local_port_range - 2 INTEGERS
|
|
Defines the local port range that is used by TCP and UDP to
|
|
choose the local port. The first number is the first, the
|
|
second the last local port number. Default value depends on
|
|
amount of memory available on the system:
|
|
> 128Mb 32768-61000
|
|
< 128Mb 1024-4999 or even less.
|
|
This number defines number of active connections, which this
|
|
system can issue simultaneously to systems not supporting
|
|
TCP extensions (timestamps). With tcp_tw_recycle enabled
|
|
(i.e. by default) range 1024-4999 is enough to issue up to
|
|
2000 connections per second to systems supporting timestamps.
|
|
|
|
ip_nonlocal_bind - BOOLEAN
|
|
If set, allows processes to bind() to non-local IP addresses,
|
|
which can be quite useful - but may break some applications.
|
|
Default: 0
|
|
|
|
ip_dynaddr - BOOLEAN
|
|
If set non-zero, enables support for dynamic addresses.
|
|
If set to a non-zero value larger than 1, a kernel log
|
|
message will be printed when dynamic address rewriting
|
|
occurs.
|
|
Default: 0
|
|
|
|
icmp_echo_ignore_all - BOOLEAN
|
|
If set non-zero, then the kernel will ignore all ICMP ECHO
|
|
requests sent to it.
|
|
Default: 0
|
|
|
|
icmp_echo_ignore_broadcasts - BOOLEAN
|
|
If set non-zero, then the kernel will ignore all ICMP ECHO and
|
|
TIMESTAMP requests sent to it via broadcast/multicast.
|
|
Default: 1
|
|
|
|
icmp_ratelimit - INTEGER
|
|
Limit the maximal rates for sending ICMP packets whose type matches
|
|
icmp_ratemask (see below) to specific targets.
|
|
0 to disable any limiting,
|
|
otherwise the minimal space between responses in milliseconds.
|
|
Default: 1000
|
|
|
|
icmp_ratemask - INTEGER
|
|
Mask made of ICMP types for which rates are being limited.
|
|
Significant bits: IHGFEDCBA9876543210
|
|
Default mask: 0000001100000011000 (6168)
|
|
|
|
Bit definitions (see include/linux/icmp.h):
|
|
0 Echo Reply
|
|
3 Destination Unreachable *
|
|
4 Source Quench *
|
|
5 Redirect
|
|
8 Echo Request
|
|
B Time Exceeded *
|
|
C Parameter Problem *
|
|
D Timestamp Request
|
|
E Timestamp Reply
|
|
F Info Request
|
|
G Info Reply
|
|
H Address Mask Request
|
|
I Address Mask Reply
|
|
|
|
* These are rate limited by default (see default mask above)
|
|
|
|
icmp_ignore_bogus_error_responses - BOOLEAN
|
|
Some routers violate RFC1122 by sending bogus responses to broadcast
|
|
frames. Such violations are normally logged via a kernel warning.
|
|
If this is set to TRUE, the kernel will not give such warnings, which
|
|
will avoid log file clutter.
|
|
Default: FALSE
|
|
|
|
icmp_errors_use_inbound_ifaddr - BOOLEAN
|
|
|
|
If zero, icmp error messages are sent with the primary address of
|
|
the exiting interface.
|
|
|
|
If non-zero, the message will be sent with the primary address of
|
|
the interface that received the packet that caused the icmp error.
|
|
This is the behaviour network many administrators will expect from
|
|
a router. And it can make debugging complicated network layouts
|
|
much easier.
|
|
|
|
Note that if no primary address exists for the interface selected,
|
|
then the primary address of the first non-loopback interface that
|
|
has one will be used regardless of this setting.
|
|
|
|
Default: 0
|
|
|
|
igmp_max_memberships - INTEGER
|
|
Change the maximum number of multicast groups we can subscribe to.
|
|
Default: 20
|
|
|
|
conf/interface/* changes special settings per interface (where "interface" is
|
|
the name of your network interface)
|
|
conf/all/* is special, changes the settings for all interfaces
|
|
|
|
|
|
log_martians - BOOLEAN
|
|
Log packets with impossible addresses to kernel log.
|
|
log_martians for the interface will be enabled if at least one of
|
|
conf/{all,interface}/log_martians is set to TRUE,
|
|
it will be disabled otherwise
|
|
|
|
accept_redirects - BOOLEAN
|
|
Accept ICMP redirect messages.
|
|
accept_redirects for the interface will be enabled if:
|
|
- both conf/{all,interface}/accept_redirects are TRUE in the case
|
|
forwarding for the interface is enabled
|
|
or
|
|
- at least one of conf/{all,interface}/accept_redirects is TRUE in the
|
|
case forwarding for the interface is disabled
|
|
accept_redirects for the interface will be disabled otherwise
|
|
default TRUE (host)
|
|
FALSE (router)
|
|
|
|
forwarding - BOOLEAN
|
|
Enable IP forwarding on this interface.
|
|
|
|
mc_forwarding - BOOLEAN
|
|
Do multicast routing. The kernel needs to be compiled with CONFIG_MROUTE
|
|
and a multicast routing daemon is required.
|
|
conf/all/mc_forwarding must also be set to TRUE to enable multicast
|
|
routing for the interface
|
|
|
|
medium_id - INTEGER
|
|
Integer value used to differentiate the devices by the medium they
|
|
are attached to. Two devices can have different id values when
|
|
the broadcast packets are received only on one of them.
|
|
The default value 0 means that the device is the only interface
|
|
to its medium, value of -1 means that medium is not known.
|
|
|
|
Currently, it is used to change the proxy_arp behavior:
|
|
the proxy_arp feature is enabled for packets forwarded between
|
|
two devices attached to different media.
|
|
|
|
proxy_arp - BOOLEAN
|
|
Do proxy arp.
|
|
proxy_arp for the interface will be enabled if at least one of
|
|
conf/{all,interface}/proxy_arp is set to TRUE,
|
|
it will be disabled otherwise
|
|
|
|
shared_media - BOOLEAN
|
|
Send(router) or accept(host) RFC1620 shared media redirects.
|
|
Overrides ip_secure_redirects.
|
|
shared_media for the interface will be enabled if at least one of
|
|
conf/{all,interface}/shared_media is set to TRUE,
|
|
it will be disabled otherwise
|
|
default TRUE
|
|
|
|
secure_redirects - BOOLEAN
|
|
Accept ICMP redirect messages only for gateways,
|
|
listed in default gateway list.
|
|
secure_redirects for the interface will be enabled if at least one of
|
|
conf/{all,interface}/secure_redirects is set to TRUE,
|
|
it will be disabled otherwise
|
|
default TRUE
|
|
|
|
send_redirects - BOOLEAN
|
|
Send redirects, if router.
|
|
send_redirects for the interface will be enabled if at least one of
|
|
conf/{all,interface}/send_redirects is set to TRUE,
|
|
it will be disabled otherwise
|
|
Default: TRUE
|
|
|
|
bootp_relay - BOOLEAN
|
|
Accept packets with source address 0.b.c.d destined
|
|
not to this host as local ones. It is supposed, that
|
|
BOOTP relay daemon will catch and forward such packets.
|
|
conf/all/bootp_relay must also be set to TRUE to enable BOOTP relay
|
|
for the interface
|
|
default FALSE
|
|
Not Implemented Yet.
|
|
|
|
accept_source_route - BOOLEAN
|
|
Accept packets with SRR option.
|
|
conf/all/accept_source_route must also be set to TRUE to accept packets
|
|
with SRR option on the interface
|
|
default TRUE (router)
|
|
FALSE (host)
|
|
|
|
accept_local - BOOLEAN
|
|
Accept packets with local source addresses. In combination with
|
|
suitable routing, this can be used to direct packets between two
|
|
local interfaces over the wire and have them accepted properly.
|
|
default FALSE
|
|
|
|
rp_filter - INTEGER
|
|
0 - No source validation.
|
|
1 - Strict mode as defined in RFC3704 Strict Reverse Path
|
|
Each incoming packet is tested against the FIB and if the interface
|
|
is not the best reverse path the packet check will fail.
|
|
By default failed packets are discarded.
|
|
2 - Loose mode as defined in RFC3704 Loose Reverse Path
|
|
Each incoming packet's source address is also tested against the FIB
|
|
and if the source address is not reachable via any interface
|
|
the packet check will fail.
|
|
|
|
Current recommended practice in RFC3704 is to enable strict mode
|
|
to prevent IP spoofing from DDos attacks. If using asymmetric routing
|
|
or other complicated routing, then loose mode is recommended.
|
|
|
|
The max value from conf/{all,interface}/rp_filter is used
|
|
when doing source validation on the {interface}.
|
|
|
|
Default value is 0. Note that some distributions enable it
|
|
in startup scripts.
|
|
|
|
arp_filter - BOOLEAN
|
|
1 - Allows you to have multiple network interfaces on the same
|
|
subnet, and have the ARPs for each interface be answered
|
|
based on whether or not the kernel would route a packet from
|
|
the ARP'd IP out that interface (therefore you must use source
|
|
based routing for this to work). In other words it allows control
|
|
of which cards (usually 1) will respond to an arp request.
|
|
|
|
0 - (default) The kernel can respond to arp requests with addresses
|
|
from other interfaces. This may seem wrong but it usually makes
|
|
sense, because it increases the chance of successful communication.
|
|
IP addresses are owned by the complete host on Linux, not by
|
|
particular interfaces. Only for more complex setups like load-
|
|
balancing, does this behaviour cause problems.
|
|
|
|
arp_filter for the interface will be enabled if at least one of
|
|
conf/{all,interface}/arp_filter is set to TRUE,
|
|
it will be disabled otherwise
|
|
|
|
arp_announce - INTEGER
|
|
Define different restriction levels for announcing the local
|
|
source IP address from IP packets in ARP requests sent on
|
|
interface:
|
|
0 - (default) Use any local address, configured on any interface
|
|
1 - Try to avoid local addresses that are not in the target's
|
|
subnet for this interface. This mode is useful when target
|
|
hosts reachable via this interface require the source IP
|
|
address in ARP requests to be part of their logical network
|
|
configured on the receiving interface. When we generate the
|
|
request we will check all our subnets that include the
|
|
target IP and will preserve the source address if it is from
|
|
such subnet. If there is no such subnet we select source
|
|
address according to the rules for level 2.
|
|
2 - Always use the best local address for this target.
|
|
In this mode we ignore the source address in the IP packet
|
|
and try to select local address that we prefer for talks with
|
|
the target host. Such local address is selected by looking
|
|
for primary IP addresses on all our subnets on the outgoing
|
|
interface that include the target IP address. If no suitable
|
|
local address is found we select the first local address
|
|
we have on the outgoing interface or on all other interfaces,
|
|
with the hope we will receive reply for our request and
|
|
even sometimes no matter the source IP address we announce.
|
|
|
|
The max value from conf/{all,interface}/arp_announce is used.
|
|
|
|
Increasing the restriction level gives more chance for
|
|
receiving answer from the resolved target while decreasing
|
|
the level announces more valid sender's information.
|
|
|
|
arp_ignore - INTEGER
|
|
Define different modes for sending replies in response to
|
|
received ARP requests that resolve local target IP addresses:
|
|
0 - (default): reply for any local target IP address, configured
|
|
on any interface
|
|
1 - reply only if the target IP address is local address
|
|
configured on the incoming interface
|
|
2 - reply only if the target IP address is local address
|
|
configured on the incoming interface and both with the
|
|
sender's IP address are part from same subnet on this interface
|
|
3 - do not reply for local addresses configured with scope host,
|
|
only resolutions for global and link addresses are replied
|
|
4-7 - reserved
|
|
8 - do not reply for all local addresses
|
|
|
|
The max value from conf/{all,interface}/arp_ignore is used
|
|
when ARP request is received on the {interface}
|
|
|
|
arp_notify - BOOLEAN
|
|
Define mode for notification of address and device changes.
|
|
0 - (default): do nothing
|
|
1 - Generate gratuitous arp replies when device is brought up
|
|
or hardware address changes.
|
|
|
|
arp_accept - BOOLEAN
|
|
Define behavior when gratuitous arp replies are received:
|
|
0 - drop gratuitous arp frames
|
|
1 - accept gratuitous arp frames
|
|
|
|
app_solicit - INTEGER
|
|
The maximum number of probes to send to the user space ARP daemon
|
|
via netlink before dropping back to multicast probes (see
|
|
mcast_solicit). Defaults to 0.
|
|
|
|
disable_policy - BOOLEAN
|
|
Disable IPSEC policy (SPD) for this interface
|
|
|
|
disable_xfrm - BOOLEAN
|
|
Disable IPSEC encryption on this interface, whatever the policy
|
|
|
|
|
|
|
|
tag - INTEGER
|
|
Allows you to write a number, which can be used as required.
|
|
Default value is 0.
|
|
|
|
Alexey Kuznetsov.
|
|
kuznet@ms2.inr.ac.ru
|
|
|
|
Updated by:
|
|
Andi Kleen
|
|
ak@muc.de
|
|
Nicolas Delon
|
|
delon.nicolas@wanadoo.fr
|
|
|
|
|
|
|
|
|
|
/proc/sys/net/ipv6/* Variables:
|
|
|
|
IPv6 has no global variables such as tcp_*. tcp_* settings under ipv4/ also
|
|
apply to IPv6 [XXX?].
|
|
|
|
bindv6only - BOOLEAN
|
|
Default value for IPV6_V6ONLY socket option,
|
|
which restricts use of the IPv6 socket to IPv6 communication
|
|
only.
|
|
TRUE: disable IPv4-mapped address feature
|
|
FALSE: enable IPv4-mapped address feature
|
|
|
|
Default: FALSE (as specified in RFC2553bis)
|
|
|
|
IPv6 Fragmentation:
|
|
|
|
ip6frag_high_thresh - INTEGER
|
|
Maximum memory used to reassemble IPv6 fragments. When
|
|
ip6frag_high_thresh bytes of memory is allocated for this purpose,
|
|
the fragment handler will toss packets until ip6frag_low_thresh
|
|
is reached.
|
|
|
|
ip6frag_low_thresh - INTEGER
|
|
See ip6frag_high_thresh
|
|
|
|
ip6frag_time - INTEGER
|
|
Time in seconds to keep an IPv6 fragment in memory.
|
|
|
|
ip6frag_secret_interval - INTEGER
|
|
Regeneration interval (in seconds) of the hash secret (or lifetime
|
|
for the hash secret) for IPv6 fragments.
|
|
Default: 600
|
|
|
|
conf/default/*:
|
|
Change the interface-specific default settings.
|
|
|
|
|
|
conf/all/*:
|
|
Change all the interface-specific settings.
|
|
|
|
[XXX: Other special features than forwarding?]
|
|
|
|
conf/all/forwarding - BOOLEAN
|
|
Enable global IPv6 forwarding between all interfaces.
|
|
|
|
IPv4 and IPv6 work differently here; e.g. netfilter must be used
|
|
to control which interfaces may forward packets and which not.
|
|
|
|
This also sets all interfaces' Host/Router setting
|
|
'forwarding' to the specified value. See below for details.
|
|
|
|
This referred to as global forwarding.
|
|
|
|
proxy_ndp - BOOLEAN
|
|
Do proxy ndp.
|
|
|
|
conf/interface/*:
|
|
Change special settings per interface.
|
|
|
|
The functional behaviour for certain settings is different
|
|
depending on whether local forwarding is enabled or not.
|
|
|
|
accept_ra - BOOLEAN
|
|
Accept Router Advertisements; autoconfigure using them.
|
|
|
|
Functional default: enabled if local forwarding is disabled.
|
|
disabled if local forwarding is enabled.
|
|
|
|
accept_ra_defrtr - BOOLEAN
|
|
Learn default router in Router Advertisement.
|
|
|
|
Functional default: enabled if accept_ra is enabled.
|
|
disabled if accept_ra is disabled.
|
|
|
|
accept_ra_pinfo - BOOLEAN
|
|
Learn Prefix Information in Router Advertisement.
|
|
|
|
Functional default: enabled if accept_ra is enabled.
|
|
disabled if accept_ra is disabled.
|
|
|
|
accept_ra_rt_info_max_plen - INTEGER
|
|
Maximum prefix length of Route Information in RA.
|
|
|
|
Route Information w/ prefix larger than or equal to this
|
|
variable shall be ignored.
|
|
|
|
Functional default: 0 if accept_ra_rtr_pref is enabled.
|
|
-1 if accept_ra_rtr_pref is disabled.
|
|
|
|
accept_ra_rtr_pref - BOOLEAN
|
|
Accept Router Preference in RA.
|
|
|
|
Functional default: enabled if accept_ra is enabled.
|
|
disabled if accept_ra is disabled.
|
|
|
|
accept_redirects - BOOLEAN
|
|
Accept Redirects.
|
|
|
|
Functional default: enabled if local forwarding is disabled.
|
|
disabled if local forwarding is enabled.
|
|
|
|
accept_source_route - INTEGER
|
|
Accept source routing (routing extension header).
|
|
|
|
>= 0: Accept only routing header type 2.
|
|
< 0: Do not accept routing header.
|
|
|
|
Default: 0
|
|
|
|
autoconf - BOOLEAN
|
|
Autoconfigure addresses using Prefix Information in Router
|
|
Advertisements.
|
|
|
|
Functional default: enabled if accept_ra_pinfo is enabled.
|
|
disabled if accept_ra_pinfo is disabled.
|
|
|
|
dad_transmits - INTEGER
|
|
The amount of Duplicate Address Detection probes to send.
|
|
Default: 1
|
|
|
|
forwarding - BOOLEAN
|
|
Configure interface-specific Host/Router behaviour.
|
|
|
|
Note: It is recommended to have the same setting on all
|
|
interfaces; mixed router/host scenarios are rather uncommon.
|
|
|
|
FALSE:
|
|
|
|
By default, Host behaviour is assumed. This means:
|
|
|
|
1. IsRouter flag is not set in Neighbour Advertisements.
|
|
2. Router Solicitations are being sent when necessary.
|
|
3. If accept_ra is TRUE (default), accept Router
|
|
Advertisements (and do autoconfiguration).
|
|
4. If accept_redirects is TRUE (default), accept Redirects.
|
|
|
|
TRUE:
|
|
|
|
If local forwarding is enabled, Router behaviour is assumed.
|
|
This means exactly the reverse from the above:
|
|
|
|
1. IsRouter flag is set in Neighbour Advertisements.
|
|
2. Router Solicitations are not sent.
|
|
3. Router Advertisements are ignored.
|
|
4. Redirects are ignored.
|
|
|
|
Default: FALSE if global forwarding is disabled (default),
|
|
otherwise TRUE.
|
|
|
|
hop_limit - INTEGER
|
|
Default Hop Limit to set.
|
|
Default: 64
|
|
|
|
mtu - INTEGER
|
|
Default Maximum Transfer Unit
|
|
Default: 1280 (IPv6 required minimum)
|
|
|
|
router_probe_interval - INTEGER
|
|
Minimum interval (in seconds) between Router Probing described
|
|
in RFC4191.
|
|
|
|
Default: 60
|
|
|
|
router_solicitation_delay - INTEGER
|
|
Number of seconds to wait after interface is brought up
|
|
before sending Router Solicitations.
|
|
Default: 1
|
|
|
|
router_solicitation_interval - INTEGER
|
|
Number of seconds to wait between Router Solicitations.
|
|
Default: 4
|
|
|
|
router_solicitations - INTEGER
|
|
Number of Router Solicitations to send until assuming no
|
|
routers are present.
|
|
Default: 3
|
|
|
|
use_tempaddr - INTEGER
|
|
Preference for Privacy Extensions (RFC3041).
|
|
<= 0 : disable Privacy Extensions
|
|
== 1 : enable Privacy Extensions, but prefer public
|
|
addresses over temporary addresses.
|
|
> 1 : enable Privacy Extensions and prefer temporary
|
|
addresses over public addresses.
|
|
Default: 0 (for most devices)
|
|
-1 (for point-to-point devices and loopback devices)
|
|
|
|
temp_valid_lft - INTEGER
|
|
valid lifetime (in seconds) for temporary addresses.
|
|
Default: 604800 (7 days)
|
|
|
|
temp_prefered_lft - INTEGER
|
|
Preferred lifetime (in seconds) for temporary addresses.
|
|
Default: 86400 (1 day)
|
|
|
|
max_desync_factor - INTEGER
|
|
Maximum value for DESYNC_FACTOR, which is a random value
|
|
that ensures that clients don't synchronize with each
|
|
other and generate new addresses at exactly the same time.
|
|
value is in seconds.
|
|
Default: 600
|
|
|
|
regen_max_retry - INTEGER
|
|
Number of attempts before give up attempting to generate
|
|
valid temporary addresses.
|
|
Default: 5
|
|
|
|
max_addresses - INTEGER
|
|
Maximum number of autoconfigured addresses per interface. Setting
|
|
to zero disables the limitation. It is not recommended to set this
|
|
value too large (or to zero) because it would be an easy way to
|
|
crash the kernel by allowing too many addresses to be created.
|
|
Default: 16
|
|
|
|
disable_ipv6 - BOOLEAN
|
|
Disable IPv6 operation. If accept_dad is set to 2, this value
|
|
will be dynamically set to TRUE if DAD fails for the link-local
|
|
address.
|
|
Default: FALSE (enable IPv6 operation)
|
|
|
|
When this value is changed from 1 to 0 (IPv6 is being enabled),
|
|
it will dynamically create a link-local address on the given
|
|
interface and start Duplicate Address Detection, if necessary.
|
|
|
|
When this value is changed from 0 to 1 (IPv6 is being disabled),
|
|
it will dynamically delete all address on the given interface.
|
|
|
|
accept_dad - INTEGER
|
|
Whether to accept DAD (Duplicate Address Detection).
|
|
0: Disable DAD
|
|
1: Enable DAD (default)
|
|
2: Enable DAD, and disable IPv6 operation if MAC-based duplicate
|
|
link-local address has been found.
|
|
|
|
force_tllao - BOOLEAN
|
|
Enable sending the target link-layer address option even when
|
|
responding to a unicast neighbor solicitation.
|
|
Default: FALSE
|
|
|
|
Quoting from RFC 2461, section 4.4, Target link-layer address:
|
|
|
|
"The option MUST be included for multicast solicitations in order to
|
|
avoid infinite Neighbor Solicitation "recursion" when the peer node
|
|
does not have a cache entry to return a Neighbor Advertisements
|
|
message. When responding to unicast solicitations, the option can be
|
|
omitted since the sender of the solicitation has the correct link-
|
|
layer address; otherwise it would not have be able to send the unicast
|
|
solicitation in the first place. However, including the link-layer
|
|
address in this case adds little overhead and eliminates a potential
|
|
race condition where the sender deletes the cached link-layer address
|
|
prior to receiving a response to a previous solicitation."
|
|
|
|
icmp/*:
|
|
ratelimit - INTEGER
|
|
Limit the maximal rates for sending ICMPv6 packets.
|
|
0 to disable any limiting,
|
|
otherwise the minimal space between responses in milliseconds.
|
|
Default: 1000
|
|
|
|
|
|
IPv6 Update by:
|
|
Pekka Savola <pekkas@netcore.fi>
|
|
YOSHIFUJI Hideaki / USAGI Project <yoshfuji@linux-ipv6.org>
|
|
|
|
|
|
/proc/sys/net/bridge/* Variables:
|
|
|
|
bridge-nf-call-arptables - BOOLEAN
|
|
1 : pass bridged ARP traffic to arptables' FORWARD chain.
|
|
0 : disable this.
|
|
Default: 1
|
|
|
|
bridge-nf-call-iptables - BOOLEAN
|
|
1 : pass bridged IPv4 traffic to iptables' chains.
|
|
0 : disable this.
|
|
Default: 1
|
|
|
|
bridge-nf-call-ip6tables - BOOLEAN
|
|
1 : pass bridged IPv6 traffic to ip6tables' chains.
|
|
0 : disable this.
|
|
Default: 1
|
|
|
|
bridge-nf-filter-vlan-tagged - BOOLEAN
|
|
1 : pass bridged vlan-tagged ARP/IP/IPv6 traffic to {arp,ip,ip6}tables.
|
|
0 : disable this.
|
|
Default: 1
|
|
|
|
bridge-nf-filter-pppoe-tagged - BOOLEAN
|
|
1 : pass bridged pppoe-tagged IP/IPv6 traffic to {ip,ip6}tables.
|
|
0 : disable this.
|
|
Default: 1
|
|
|
|
|
|
proc/sys/net/sctp/* Variables:
|
|
|
|
addip_enable - BOOLEAN
|
|
Enable or disable extension of Dynamic Address Reconfiguration
|
|
(ADD-IP) functionality specified in RFC5061. This extension provides
|
|
the ability to dynamically add and remove new addresses for the SCTP
|
|
associations.
|
|
|
|
1: Enable extension.
|
|
|
|
0: Disable extension.
|
|
|
|
Default: 0
|
|
|
|
addip_noauth_enable - BOOLEAN
|
|
Dynamic Address Reconfiguration (ADD-IP) requires the use of
|
|
authentication to protect the operations of adding or removing new
|
|
addresses. This requirement is mandated so that unauthorized hosts
|
|
would not be able to hijack associations. However, older
|
|
implementations may not have implemented this requirement while
|
|
allowing the ADD-IP extension. For reasons of interoperability,
|
|
we provide this variable to control the enforcement of the
|
|
authentication requirement.
|
|
|
|
1: Allow ADD-IP extension to be used without authentication. This
|
|
should only be set in a closed environment for interoperability
|
|
with older implementations.
|
|
|
|
0: Enforce the authentication requirement
|
|
|
|
Default: 0
|
|
|
|
auth_enable - BOOLEAN
|
|
Enable or disable Authenticated Chunks extension. This extension
|
|
provides the ability to send and receive authenticated chunks and is
|
|
required for secure operation of Dynamic Address Reconfiguration
|
|
(ADD-IP) extension.
|
|
|
|
1: Enable this extension.
|
|
0: Disable this extension.
|
|
|
|
Default: 0
|
|
|
|
prsctp_enable - BOOLEAN
|
|
Enable or disable the Partial Reliability extension (RFC3758) which
|
|
is used to notify peers that a given DATA should no longer be expected.
|
|
|
|
1: Enable extension
|
|
0: Disable
|
|
|
|
Default: 1
|
|
|
|
max_burst - INTEGER
|
|
The limit of the number of new packets that can be initially sent. It
|
|
controls how bursty the generated traffic can be.
|
|
|
|
Default: 4
|
|
|
|
association_max_retrans - INTEGER
|
|
Set the maximum number for retransmissions that an association can
|
|
attempt deciding that the remote end is unreachable. If this value
|
|
is exceeded, the association is terminated.
|
|
|
|
Default: 10
|
|
|
|
max_init_retransmits - INTEGER
|
|
The maximum number of retransmissions of INIT and COOKIE-ECHO chunks
|
|
that an association will attempt before declaring the destination
|
|
unreachable and terminating.
|
|
|
|
Default: 8
|
|
|
|
path_max_retrans - INTEGER
|
|
The maximum number of retransmissions that will be attempted on a given
|
|
path. Once this threshold is exceeded, the path is considered
|
|
unreachable, and new traffic will use a different path when the
|
|
association is multihomed.
|
|
|
|
Default: 5
|
|
|
|
rto_initial - INTEGER
|
|
The initial round trip timeout value in milliseconds that will be used
|
|
in calculating round trip times. This is the initial time interval
|
|
for retransmissions.
|
|
|
|
Default: 3000
|
|
|
|
rto_max - INTEGER
|
|
The maximum value (in milliseconds) of the round trip timeout. This
|
|
is the largest time interval that can elapse between retransmissions.
|
|
|
|
Default: 60000
|
|
|
|
rto_min - INTEGER
|
|
The minimum value (in milliseconds) of the round trip timeout. This
|
|
is the smallest time interval the can elapse between retransmissions.
|
|
|
|
Default: 1000
|
|
|
|
hb_interval - INTEGER
|
|
The interval (in milliseconds) between HEARTBEAT chunks. These chunks
|
|
are sent at the specified interval on idle paths to probe the state of
|
|
a given path between 2 associations.
|
|
|
|
Default: 30000
|
|
|
|
sack_timeout - INTEGER
|
|
The amount of time (in milliseconds) that the implementation will wait
|
|
to send a SACK.
|
|
|
|
Default: 200
|
|
|
|
valid_cookie_life - INTEGER
|
|
The default lifetime of the SCTP cookie (in milliseconds). The cookie
|
|
is used during association establishment.
|
|
|
|
Default: 60000
|
|
|
|
cookie_preserve_enable - BOOLEAN
|
|
Enable or disable the ability to extend the lifetime of the SCTP cookie
|
|
that is used during the establishment phase of SCTP association
|
|
|
|
1: Enable cookie lifetime extension.
|
|
0: Disable
|
|
|
|
Default: 1
|
|
|
|
rcvbuf_policy - INTEGER
|
|
Determines if the receive buffer is attributed to the socket or to
|
|
association. SCTP supports the capability to create multiple
|
|
associations on a single socket. When using this capability, it is
|
|
possible that a single stalled association that's buffering a lot
|
|
of data may block other associations from delivering their data by
|
|
consuming all of the receive buffer space. To work around this,
|
|
the rcvbuf_policy could be set to attribute the receiver buffer space
|
|
to each association instead of the socket. This prevents the described
|
|
blocking.
|
|
|
|
1: rcvbuf space is per association
|
|
0: recbuf space is per socket
|
|
|
|
Default: 0
|
|
|
|
sndbuf_policy - INTEGER
|
|
Similar to rcvbuf_policy above, this applies to send buffer space.
|
|
|
|
1: Send buffer is tracked per association
|
|
0: Send buffer is tracked per socket.
|
|
|
|
Default: 0
|
|
|
|
sctp_mem - vector of 3 INTEGERs: min, pressure, max
|
|
Number of pages allowed for queueing by all SCTP sockets.
|
|
|
|
min: Below this number of pages SCTP is not bothered about its
|
|
memory appetite. When amount of memory allocated by SCTP exceeds
|
|
this number, SCTP starts to moderate memory usage.
|
|
|
|
pressure: This value was introduced to follow format of tcp_mem.
|
|
|
|
max: Number of pages allowed for queueing by all SCTP sockets.
|
|
|
|
Default is calculated at boot time from amount of available memory.
|
|
|
|
sctp_rmem - vector of 3 INTEGERs: min, default, max
|
|
See tcp_rmem for a description.
|
|
|
|
sctp_wmem - vector of 3 INTEGERs: min, default, max
|
|
See tcp_wmem for a description.
|
|
|
|
addr_scope_policy - INTEGER
|
|
Control IPv4 address scoping - draft-stewart-tsvwg-sctp-ipv4-00
|
|
|
|
0 - Disable IPv4 address scoping
|
|
1 - Enable IPv4 address scoping
|
|
2 - Follow draft but allow IPv4 private addresses
|
|
3 - Follow draft but allow IPv4 link local addresses
|
|
|
|
Default: 1
|
|
|
|
|
|
/proc/sys/net/core/*
|
|
dev_weight - INTEGER
|
|
The maximum number of packets that kernel can handle on a NAPI
|
|
interrupt, it's a Per-CPU variable.
|
|
|
|
Default: 64
|
|
|
|
/proc/sys/net/unix/*
|
|
max_dgram_qlen - INTEGER
|
|
The maximum length of dgram socket receive queue
|
|
|
|
Default: 10
|
|
|
|
|
|
UNDOCUMENTED:
|
|
|
|
/proc/sys/net/irda/*
|
|
fast_poll_increase FIXME
|
|
warn_noreply_time FIXME
|
|
discovery_slots FIXME
|
|
slot_timeout FIXME
|
|
max_baud_rate FIXME
|
|
discovery_timeout FIXME
|
|
lap_keepalive_time FIXME
|
|
max_noreply_time FIXME
|
|
max_tx_data_size FIXME
|
|
max_tx_window FIXME
|
|
min_tx_turn_time FIXME
|