| blob | ab65714d95fcec32b6103c384f05bd06ab84c506 |
1 /proc/sys/net/ipv4/* Variables:
3 ip_forward - BOOLEAN
4 0 - disabled (default)
5 not 0 - enabled
7 Forward Packets between interfaces.
9 This variable is special, its change resets all configuration
10 parameters to their default state (RFC1122 for hosts, RFC1812
11 for routers)
13 ip_default_ttl - INTEGER
14 default 64
16 ip_no_pmtu_disc - BOOLEAN
17 Disable Path MTU Discovery.
18 default FALSE
20 min_pmtu - INTEGER
21 default 562 - minimum discovered Path MTU
23 mtu_expires - INTEGER
24 Time, in seconds, that cached PMTU information is kept.
26 min_adv_mss - INTEGER
27 The advertised MSS depends on the first hop route MTU, but will
28 never be lower than this setting.
30 IP Fragmentation:
32 ipfrag_high_thresh - INTEGER
33 Maximum memory used to reassemble IP fragments. When
34 ipfrag_high_thresh bytes of memory is allocated for this purpose,
35 the fragment handler will toss packets until ipfrag_low_thresh
36 is reached.
38 ipfrag_low_thresh - INTEGER
39 See ipfrag_high_thresh
41 ipfrag_time - INTEGER
42 Time in seconds to keep an IP fragment in memory.
44 ipfrag_secret_interval - INTEGER
45 Regeneration interval (in seconds) of the hash secret (or lifetime
46 for the hash secret) for IP fragments.
47 Default: 600
49 INET peer storage:
51 inet_peer_threshold - INTEGER
52 The approximate size of the storage. Starting from this threshold
53 entries will be thrown aggressively. This threshold also determines
54 entries' time-to-live and time intervals between garbage collection
55 passes. More entries, less time-to-live, less GC interval.
57 inet_peer_minttl - INTEGER
58 Minimum time-to-live of entries. Should be enough to cover fragment
59 time-to-live on the reassembling side. This minimum time-to-live is
60 guaranteed if the pool size is less than inet_peer_threshold.
61 Measured in jiffies(1).
63 inet_peer_maxttl - INTEGER
64 Maximum time-to-live of entries. Unused entries will expire after
65 this period of time if there is no memory pressure on the pool (i.e.
66 when the number of entries in the pool is very small).
67 Measured in jiffies(1).
69 inet_peer_gc_mintime - INTEGER
70 Minimum interval between garbage collection passes. This interval is
71 in effect under high memory pressure on the pool.
72 Measured in jiffies(1).
74 inet_peer_gc_maxtime - INTEGER
75 Minimum interval between garbage collection passes. This interval is
76 in effect under low (or absent) memory pressure on the pool.
77 Measured in jiffies(1).
79 TCP variables:
81 tcp_syn_retries - INTEGER
82 Number of times initial SYNs for an active TCP connection attempt
83 will be retransmitted. Should not be higher than 255. Default value
84 is 5, which corresponds to ~180seconds.
86 tcp_synack_retries - INTEGER
87 Number of times SYNACKs for a passive TCP connection attempt will
88 be retransmitted. Should not be higher than 255. Default value
89 is 5, which corresponds to ~180seconds.
91 tcp_keepalive_time - INTEGER
92 How often TCP sends out keepalive messages when keepalive is enabled.
93 Default: 2hours.
95 tcp_keepalive_probes - INTEGER
96 How many keepalive probes TCP sends out, until it decides that the
97 connection is broken. Default value: 9.
99 tcp_keepalive_intvl - INTEGER
100 How frequently the probes are send out. Multiplied by
101 tcp_keepalive_probes it is time to kill not responding connection,
102 after probes started. Default value: 75sec i.e. connection
103 will be aborted after ~11 minutes of retries.
105 tcp_retries1 - INTEGER
106 How many times to retry before deciding that something is wrong
107 and it is necessary to report this suspicion to network layer.
108 Minimal RFC value is 3, it is default, which corresponds
109 to ~3sec-8min depending on RTO.
111 tcp_retries2 - INTEGER
112 How may times to retry before killing alive TCP connection.
113 RFC1122 says that the limit should be longer than 100 sec.
114 It is too small number. Default value 15 corresponds to ~13-30min
115 depending on RTO.
117 tcp_orphan_retries - INTEGER
118 How may times to retry before killing TCP connection, closed
119 by our side. Default value 7 corresponds to ~50sec-16min
120 depending on RTO. If you machine is loaded WEB server,
121 you should think about lowering this value, such sockets
122 may consume significant resources. Cf. tcp_max_orphans.
124 tcp_fin_timeout - INTEGER
125 Time to hold socket in state FIN-WAIT-2, if it was closed
126 by our side. Peer can be broken and never close its side,
127 or even died unexpectedly. Default value is 60sec.
128 Usual value used in 2.2 was 180 seconds, you may restore
129 it, but remember that if your machine is even underloaded WEB server,
130 you risk to overflow memory with kilotons of dead sockets,
131 FIN-WAIT-2 sockets are less dangerous than FIN-WAIT-1,
132 because they eat maximum 1.5K of memory, but they tend
133 to live longer. Cf. tcp_max_orphans.
135 tcp_max_tw_buckets - INTEGER
136 Maximal number of timewait sockets held by system simultaneously.
137 If this number is exceeded time-wait socket is immediately destroyed
138 and warning is printed. This limit exists only to prevent
139 simple DoS attacks, you _must_ not lower the limit artificially,
140 but rather increase it (probably, after increasing installed memory),
141 if network conditions require more than default value.
143 tcp_tw_recycle - BOOLEAN
144 Enable fast recycling TIME-WAIT sockets. Default value is 0.
145 It should not be changed without advice/request of technical
146 experts.
148 tcp_tw_reuse - BOOLEAN
149 Allow to reuse TIME-WAIT sockets for new connections when it is
150 safe from protocol viewpoint. Default value is 0.
151 It should not be changed without advice/request of technical
152 experts.
154 tcp_max_orphans - INTEGER
155 Maximal number of TCP sockets not attached to any user file handle,
156 held by system. If this number is exceeded orphaned connections are
157 reset immediately and warning is printed. This limit exists
158 only to prevent simple DoS attacks, you _must_ not rely on this
159 or lower the limit artificially, but rather increase it
160 (probably, after increasing installed memory),
161 if network conditions require more than default value,
162 and tune network services to linger and kill such states
163 more aggressively. Let me to remind again: each orphan eats
164 up to ~64K of unswappable memory.
166 tcp_abort_on_overflow - BOOLEAN
167 If listening service is too slow to accept new connections,
168 reset them. Default state is FALSE. It means that if overflow
169 occurred due to a burst, connection will recover. Enable this
170 option _only_ if you are really sure that listening daemon
171 cannot be tuned to accept connections faster. Enabling this
172 option can harm clients of your server.
174 tcp_syncookies - BOOLEAN
175 Only valid when the kernel was compiled with CONFIG_SYNCOOKIES
176 Send out syncookies when the syn backlog queue of a socket
177 overflows. This is to prevent against the common 'syn flood attack'
178 Default: FALSE
180 Note, that syncookies is fallback facility.
181 It MUST NOT be used to help highly loaded servers to stand
182 against legal connection rate. If you see synflood warnings
183 in your logs, but investigation shows that they occur
184 because of overload with legal connections, you should tune
185 another parameters until this warning disappear.
186 See: tcp_max_syn_backlog, tcp_synack_retries, tcp_abort_on_overflow.
188 syncookies seriously violate TCP protocol, do not allow
189 to use TCP extensions, can result in serious degradation
190 of some services (f.e. SMTP relaying), visible not by you,
191 but your clients and relays, contacting you. While you see
192 synflood warnings in logs not being really flooded, your server
193 is seriously misconfigured.
195 tcp_stdurg - BOOLEAN
196 Use the Host requirements interpretation of the TCP urg pointer field.
197 Most hosts use the older BSD interpretation, so if you turn this on
198 Linux might not communicate correctly with them.
199 Default: FALSE
201 tcp_max_syn_backlog - INTEGER
202 Maximal number of remembered connection requests, which are
203 still did not receive an acknowledgment from connecting client.
204 Default value is 1024 for systems with more than 128Mb of memory,
205 and 128 for low memory machines. If server suffers of overload,
206 try to increase this number.
208 tcp_window_scaling - BOOLEAN
209 Enable window scaling as defined in RFC1323.
211 tcp_timestamps - BOOLEAN
212 Enable timestamps as defined in RFC1323.
214 tcp_sack - BOOLEAN
215 Enable select acknowledgments (SACKS).
217 tcp_fack - BOOLEAN
218 Enable FACK congestion avoidance and fast retransmission.
219 The value is not used, if tcp_sack is not enabled.
221 tcp_dsack - BOOLEAN
222 Allows TCP to send "duplicate" SACKs.
224 tcp_ecn - BOOLEAN
225 Enable Explicit Congestion Notification in TCP.
227 tcp_reordering - INTEGER
228 Maximal reordering of packets in a TCP stream.
229 Default: 3
231 tcp_retrans_collapse - BOOLEAN
232 Bug-to-bug compatibility with some broken printers.
233 On retransmit try to send bigger packets to work around bugs in
234 certain TCP stacks.
236 tcp_wmem - vector of 3 INTEGERs: min, default, max
237 min: Amount of memory reserved for send buffers for TCP socket.
238 Each TCP socket has rights to use it due to fact of its birth.
239 Default: 4K
241 default: Amount of memory allowed for send buffers for TCP socket
242 by default. This value overrides net.core.wmem_default used
243 by other protocols, it is usually lower than net.core.wmem_default.
244 Default: 16K
246 max: Maximal amount of memory allowed for automatically selected
247 send buffers for TCP socket. This value does not override
248 net.core.wmem_max, "static" selection via SO_SNDBUF does not use this.
249 Default: 128K
251 tcp_rmem - vector of 3 INTEGERs: min, default, max
252 min: Minimal size of receive buffer used by TCP sockets.
253 It is guaranteed to each TCP socket, even under moderate memory
254 pressure.
255 Default: 8K
257 default: default size of receive buffer used by TCP sockets.
258 This value overrides net.core.rmem_default used by other protocols.
259 Default: 87380 bytes. This value results in window of 65535 with
260 default setting of tcp_adv_win_scale and tcp_app_win:0 and a bit
261 less for default tcp_app_win. See below about these variables.
263 max: maximal size of receive buffer allowed for automatically
264 selected receiver buffers for TCP socket. This value does not override
265 net.core.rmem_max, "static" selection via SO_RCVBUF does not use this.
266 Default: 87380*2 bytes.
268 tcp_mem - vector of 3 INTEGERs: min, pressure, max
269 low: below this number of pages TCP is not bothered about its
270 memory appetite.
272 pressure: when amount of memory allocated by TCP exceeds this number
273 of pages, TCP moderates its memory consumption and enters memory
274 pressure mode, which is exited when memory consumption falls
275 under "low".
277 high: number of pages allowed for queueing by all TCP sockets.
279 Defaults are calculated at boot time from amount of available
280 memory.
282 tcp_app_win - INTEGER
283 Reserve max(window/2^tcp_app_win, mss) of window for application
284 buffer. Value 0 is special, it means that nothing is reserved.
285 Default: 31
287 tcp_adv_win_scale - INTEGER
288 Count buffering overhead as bytes/2^tcp_adv_win_scale
289 (if tcp_adv_win_scale > 0) or bytes-bytes/2^(-tcp_adv_win_scale),
290 if it is <= 0.
291 Default: 2
293 tcp_rfc1337 - BOOLEAN
294 If set, the TCP stack behaves conforming to RFC1337. If unset,
295 we are not conforming to RFC, but prevent TCP TIME_WAIT
296 assassination.
297 Default: 0
299 tcp_low_latency - BOOLEAN
300 If set, the TCP stack makes decisions that prefer lower
301 latency as opposed to higher throughput. By default, this
302 option is not set meaning that higher throughput is preferred.
303 An example of an application where this default should be
304 changed would be a Beowulf compute cluster.
305 Default: 0
307 tcp_tso_win_divisor - INTEGER
308 This allows control over what percentage of the congestion window
309 can be consumed by a single TSO frame.
310 The setting of this parameter is a choice between burstiness and
311 building larger TSO frames.
312 Default: 8
314 tcp_frto - BOOLEAN
315 Enables F-RTO, an enhanced recovery algorithm for TCP retransmission
316 timeouts. It is particularly beneficial in wireless environments
317 where packet loss is typically due to random radio interference
318 rather than intermediate router congestion.
320 tcp_congestion_control - STRING
321 Set the congestion control algorithm to be used for new
322 connections. The algorithm "reno" is always available, but
323 additional choices may be available based on kernel configuration.
325 somaxconn - INTEGER
326 Limit of socket listen() backlog, known in userspace as SOMAXCONN.
327 Defaults to 128. See also tcp_max_syn_backlog for additional tuning
328 for TCP sockets.
330 IP Variables:
332 ip_local_port_range - 2 INTEGERS
333 Defines the local port range that is used by TCP and UDP to
334 choose the local port. The first number is the first, the
335 second the last local port number. Default value depends on
336 amount of memory available on the system:
337 > 128Mb 32768-61000
338 < 128Mb 1024-4999 or even less.
339 This number defines number of active connections, which this
340 system can issue simultaneously to systems not supporting
341 TCP extensions (timestamps). With tcp_tw_recycle enabled
342 (i.e. by default) range 1024-4999 is enough to issue up to
343 2000 connections per second to systems supporting timestamps.
345 ip_nonlocal_bind - BOOLEAN
346 If set, allows processes to bind() to non-local IP addresses,
347 which can be quite useful - but may break some applications.
348 Default: 0
350 ip_dynaddr - BOOLEAN
351 If set non-zero, enables support for dynamic addresses.
352 If set to a non-zero value larger than 1, a kernel log
353 message will be printed when dynamic address rewriting
354 occurs.
355 Default: 0
357 icmp_echo_ignore_all - BOOLEAN
358 icmp_echo_ignore_broadcasts - BOOLEAN
359 If either is set to true, then the kernel will ignore either all
360 ICMP ECHO requests sent to it or just those to broadcast/multicast
361 addresses, respectively.
363 icmp_ratelimit - INTEGER
364 Limit the maximal rates for sending ICMP packets whose type matches
365 icmp_ratemask (see below) to specific targets.
366 0 to disable any limiting, otherwise the maximal rate in jiffies(1)
367 Default: 100
369 icmp_ratemask - INTEGER
370 Mask made of ICMP types for which rates are being limited.
371 Significant bits: IHGFEDCBA9876543210
372 Default mask: 0000001100000011000 (6168)
374 Bit definitions (see include/linux/icmp.h):
375 0 Echo Reply
376 3 Destination Unreachable *
377 4 Source Quench *
378 5 Redirect
379 8 Echo Request
380 B Time Exceeded *
381 C Parameter Problem *
382 D Timestamp Request
383 E Timestamp Reply
384 F Info Request
385 G Info Reply
386 H Address Mask Request
387 I Address Mask Reply
389 * These are rate limited by default (see default mask above)
391 icmp_ignore_bogus_error_responses - BOOLEAN
392 Some routers violate RFC1122 by sending bogus responses to broadcast
393 frames. Such violations are normally logged via a kernel warning.
394 If this is set to TRUE, the kernel will not give such warnings, which
395 will avoid log file clutter.
396 Default: FALSE
398 igmp_max_memberships - INTEGER
399 Change the maximum number of multicast groups we can subscribe to.
400 Default: 20
402 conf/interface/* changes special settings per interface (where "interface" is
403 the name of your network interface)
404 conf/all/* is special, changes the settings for all interfaces
407 log_martians - BOOLEAN
408 Log packets with impossible addresses to kernel log.
409 log_martians for the interface will be enabled if at least one of
410 conf/{all,interface}/log_martians is set to TRUE,
411 it will be disabled otherwise
413 accept_redirects - BOOLEAN
414 Accept ICMP redirect messages.
415 accept_redirects for the interface will be enabled if:
416 - both conf/{all,interface}/accept_redirects are TRUE in the case forwarding
417 for the interface is enabled
418 or
419 - at least one of conf/{all,interface}/accept_redirects is TRUE in the case
420 forwarding for the interface is disabled
421 accept_redirects for the interface will be disabled otherwise
422 default TRUE (host)
423 FALSE (router)
425 forwarding - BOOLEAN
426 Enable IP forwarding on this interface.
428 mc_forwarding - BOOLEAN
429 Do multicast routing. The kernel needs to be compiled with CONFIG_MROUTE
430 and a multicast routing daemon is required.
431 conf/all/mc_forwarding must also be set to TRUE to enable multicast routing
432 for the interface
434 medium_id - INTEGER
435 Integer value used to differentiate the devices by the medium they
436 are attached to. Two devices can have different id values when
437 the broadcast packets are received only on one of them.
438 The default value 0 means that the device is the only interface
439 to its medium, value of -1 means that medium is not known.
441 Currently, it is used to change the proxy_arp behavior:
442 the proxy_arp feature is enabled for packets forwarded between
443 two devices attached to different media.
445 proxy_arp - BOOLEAN
446 Do proxy arp.
447 proxy_arp for the interface will be enabled if at least one of
448 conf/{all,interface}/proxy_arp is set to TRUE,
449 it will be disabled otherwise
451 shared_media - BOOLEAN
452 Send(router) or accept(host) RFC1620 shared media redirects.
453 Overrides ip_secure_redirects.
454 shared_media for the interface will be enabled if at least one of
455 conf/{all,interface}/shared_media is set to TRUE,
456 it will be disabled otherwise
457 default TRUE
459 secure_redirects - BOOLEAN
460 Accept ICMP redirect messages only for gateways,
461 listed in default gateway list.
462 secure_redirects for the interface will be enabled if at least one of
463 conf/{all,interface}/secure_redirects is set to TRUE,
464 it will be disabled otherwise
465 default TRUE
467 send_redirects - BOOLEAN
468 Send redirects, if router.
469 send_redirects for the interface will be enabled if at least one of
470 conf/{all,interface}/send_redirects is set to TRUE,
471 it will be disabled otherwise
472 Default: TRUE
474 bootp_relay - BOOLEAN
475 Accept packets with source address 0.b.c.d destined
476 not to this host as local ones. It is supposed, that
477 BOOTP relay daemon will catch and forward such packets.
478 conf/all/bootp_relay must also be set to TRUE to enable BOOTP relay
479 for the interface
480 default FALSE
481 Not Implemented Yet.
483 accept_source_route - BOOLEAN
484 Accept packets with SRR option.
485 conf/all/accept_source_route must also be set to TRUE to accept packets
486 with SRR option on the interface
487 default TRUE (router)
488 FALSE (host)
490 rp_filter - BOOLEAN
491 1 - do source validation by reversed path, as specified in RFC1812
492 Recommended option for single homed hosts and stub network
493 routers. Could cause troubles for complicated (not loop free)
494 networks running a slow unreliable protocol (sort of RIP),
495 or using static routes.
497 0 - No source validation.
499 conf/all/rp_filter must also be set to TRUE to do source validation
500 on the interface
502 Default value is 0. Note that some distributions enable it
503 in startup scripts.
505 arp_filter - BOOLEAN
506 1 - Allows you to have multiple network interfaces on the same
507 subnet, and have the ARPs for each interface be answered
508 based on whether or not the kernel would route a packet from
509 the ARP'd IP out that interface (therefore you must use source
510 based routing for this to work). In other words it allows control
511 of which cards (usually 1) will respond to an arp request.
513 0 - (default) The kernel can respond to arp requests with addresses
514 from other interfaces. This may seem wrong but it usually makes
515 sense, because it increases the chance of successful communication.
516 IP addresses are owned by the complete host on Linux, not by
517 particular interfaces. Only for more complex setups like load-
518 balancing, does this behaviour cause problems.
520 arp_filter for the interface will be enabled if at least one of
521 conf/{all,interface}/arp_filter is set to TRUE,
522 it will be disabled otherwise
524 arp_announce - INTEGER
525 Define different restriction levels for announcing the local
526 source IP address from IP packets in ARP requests sent on
527 interface:
528 0 - (default) Use any local address, configured on any interface
529 1 - Try to avoid local addresses that are not in the target's
530 subnet for this interface. This mode is useful when target
531 hosts reachable via this interface require the source IP
532 address in ARP requests to be part of their logical network
533 configured on the receiving interface. When we generate the
534 request we will check all our subnets that include the
535 target IP and will preserve the source address if it is from
536 such subnet. If there is no such subnet we select source
537 address according to the rules for level 2.
538 2 - Always use the best local address for this target.
539 In this mode we ignore the source address in the IP packet
540 and try to select local address that we prefer for talks with
541 the target host. Such local address is selected by looking
542 for primary IP addresses on all our subnets on the outgoing
543 interface that include the target IP address. If no suitable
544 local address is found we select the first local address
545 we have on the outgoing interface or on all other interfaces,
546 with the hope we will receive reply for our request and
547 even sometimes no matter the source IP address we announce.
549 The max value from conf/{all,interface}/arp_announce is used.
551 Increasing the restriction level gives more chance for
552 receiving answer from the resolved target while decreasing
553 the level announces more valid sender's information.
555 arp_ignore - INTEGER
556 Define different modes for sending replies in response to
557 received ARP requests that resolve local target IP addresses:
558 0 - (default): reply for any local target IP address, configured
559 on any interface
560 1 - reply only if the target IP address is local address
561 configured on the incoming interface
562 2 - reply only if the target IP address is local address
563 configured on the incoming interface and both with the
564 sender's IP address are part from same subnet on this interface
565 3 - do not reply for local addresses configured with scope host,
566 only resolutions for global and link addresses are replied
567 4-7 - reserved
568 8 - do not reply for all local addresses
570 The max value from conf/{all,interface}/arp_ignore is used
571 when ARP request is received on the {interface}
573 app_solicit - INTEGER
574 The maximum number of probes to send to the user space ARP daemon
575 via netlink before dropping back to multicast probes (see
576 mcast_solicit). Defaults to 0.
578 disable_policy - BOOLEAN
579 Disable IPSEC policy (SPD) for this interface
581 disable_xfrm - BOOLEAN
582 Disable IPSEC encryption on this interface, whatever the policy
586 tag - INTEGER
587 Allows you to write a number, which can be used as required.
588 Default value is 0.
590 (1) Jiffie: internal timeunit for the kernel. On the i386 1/100s, on the
591 Alpha 1/1024s. See the HZ define in /usr/include/asm/param.h for the exact
592 value on your system.
594 Alexey Kuznetsov.
595 kuznet@ms2.inr.ac.ru
597 Updated by:
598 Andi Kleen
599 ak@muc.de
600 Nicolas Delon
601 delon.nicolas@wanadoo.fr
606 /proc/sys/net/ipv6/* Variables:
608 IPv6 has no global variables such as tcp_*. tcp_* settings under ipv4/ also
609 apply to IPv6 [XXX?].
611 bindv6only - BOOLEAN
612 Default value for IPV6_V6ONLY socket option,
613 which restricts use of the IPv6 socket to IPv6 communication
614 only.
615 TRUE: disable IPv4-mapped address feature
616 FALSE: enable IPv4-mapped address feature
618 Default: FALSE (as specified in RFC2553bis)
620 IPv6 Fragmentation:
622 ip6frag_high_thresh - INTEGER
623 Maximum memory used to reassemble IPv6 fragments. When
624 ip6frag_high_thresh bytes of memory is allocated for this purpose,
625 the fragment handler will toss packets until ip6frag_low_thresh
626 is reached.
628 ip6frag_low_thresh - INTEGER
629 See ip6frag_high_thresh
631 ip6frag_time - INTEGER
632 Time in seconds to keep an IPv6 fragment in memory.
634 ip6frag_secret_interval - INTEGER
635 Regeneration interval (in seconds) of the hash secret (or lifetime
636 for the hash secret) for IPv6 fragments.
637 Default: 600
639 conf/default/*:
640 Change the interface-specific default settings.
643 conf/all/*:
644 Change all the interface-specific settings.
646 [XXX: Other special features than forwarding?]
648 conf/all/forwarding - BOOLEAN
649 Enable global IPv6 forwarding between all interfaces.
651 IPv4 and IPv6 work differently here; e.g. netfilter must be used
652 to control which interfaces may forward packets and which not.
654 This also sets all interfaces' Host/Router setting
655 'forwarding' to the specified value. See below for details.
657 This referred to as global forwarding.
659 conf/interface/*:
660 Change special settings per interface.
662 The functional behaviour for certain settings is different
663 depending on whether local forwarding is enabled or not.
665 accept_ra - BOOLEAN
666 Accept Router Advertisements; autoconfigure using them.
668 Functional default: enabled if local forwarding is disabled.
669 disabled if local forwarding is enabled.
671 accept_redirects - BOOLEAN
672 Accept Redirects.
674 Functional default: enabled if local forwarding is disabled.
675 disabled if local forwarding is enabled.
677 autoconf - BOOLEAN
678 Autoconfigure addresses using Prefix Information in Router
679 Advertisements.
681 Functional default: enabled if accept_ra is enabled.
682 disabled if accept_ra is disabled.
684 dad_transmits - INTEGER
685 The amount of Duplicate Address Detection probes to send.
686 Default: 1
688 forwarding - BOOLEAN
689 Configure interface-specific Host/Router behaviour.
691 Note: It is recommended to have the same setting on all
692 interfaces; mixed router/host scenarios are rather uncommon.
694 FALSE:
696 By default, Host behaviour is assumed. This means:
698 1. IsRouter flag is not set in Neighbour Advertisements.
699 2. Router Solicitations are being sent when necessary.
700 3. If accept_ra is TRUE (default), accept Router
701 Advertisements (and do autoconfiguration).
702 4. If accept_redirects is TRUE (default), accept Redirects.
704 TRUE:
706 If local forwarding is enabled, Router behaviour is assumed.
707 This means exactly the reverse from the above:
709 1. IsRouter flag is set in Neighbour Advertisements.
710 2. Router Solicitations are not sent.
711 3. Router Advertisements are ignored.
712 4. Redirects are ignored.
714 Default: FALSE if global forwarding is disabled (default),
715 otherwise TRUE.
717 hop_limit - INTEGER
718 Default Hop Limit to set.
719 Default: 64
721 mtu - INTEGER
722 Default Maximum Transfer Unit
723 Default: 1280 (IPv6 required minimum)
725 router_solicitation_delay - INTEGER
726 Number of seconds to wait after interface is brought up
727 before sending Router Solicitations.
728 Default: 1
730 router_solicitation_interval - INTEGER
731 Number of seconds to wait between Router Solicitations.
732 Default: 4
734 router_solicitations - INTEGER
735 Number of Router Solicitations to send until assuming no
736 routers are present.
737 Default: 3
739 use_tempaddr - INTEGER
740 Preference for Privacy Extensions (RFC3041).
741 <= 0 : disable Privacy Extensions
742 == 1 : enable Privacy Extensions, but prefer public
743 addresses over temporary addresses.
744 > 1 : enable Privacy Extensions and prefer temporary
745 addresses over public addresses.
746 Default: 0 (for most devices)
747 -1 (for point-to-point devices and loopback devices)
749 temp_valid_lft - INTEGER
750 valid lifetime (in seconds) for temporary addresses.
751 Default: 604800 (7 days)
753 temp_prefered_lft - INTEGER
754 Preferred lifetime (in seconds) for temporary addresses.
755 Default: 86400 (1 day)
757 max_desync_factor - INTEGER
758 Maximum value for DESYNC_FACTOR, which is a random value
759 that ensures that clients don't synchronize with each
760 other and generate new addresses at exactly the same time.
761 value is in seconds.
762 Default: 600
764 regen_max_retry - INTEGER
765 Number of attempts before give up attempting to generate
766 valid temporary addresses.
767 Default: 5
769 max_addresses - INTEGER
770 Number of maximum addresses per interface. 0 disables limitation.
771 It is recommended not set too large value (or 0) because it would
772 be too easy way to crash kernel to allow to create too much of
773 autoconfigured addresses.
774 Default: 16
776 icmp/*:
777 ratelimit - INTEGER
778 Limit the maximal rates for sending ICMPv6 packets.
779 0 to disable any limiting, otherwise the maximal rate in jiffies(1)
780 Default: 100
783 IPv6 Update by:
784 Pekka Savola <pekkas@netcore.fi>
785 YOSHIFUJI Hideaki / USAGI Project <yoshfuji@linux-ipv6.org>
788 /proc/sys/net/bridge/* Variables:
790 bridge-nf-call-arptables - BOOLEAN
791 1 : pass bridged ARP traffic to arptables' FORWARD chain.
792 0 : disable this.
793 Default: 1
795 bridge-nf-call-iptables - BOOLEAN
796 1 : pass bridged IPv4 traffic to iptables' chains.
797 0 : disable this.
798 Default: 1
800 bridge-nf-call-ip6tables - BOOLEAN
801 1 : pass bridged IPv6 traffic to ip6tables' chains.
802 0 : disable this.
803 Default: 1
805 bridge-nf-filter-vlan-tagged - BOOLEAN
806 1 : pass bridged vlan-tagged ARP/IP traffic to arptables/iptables.
807 0 : disable this.
808 Default: 1
811 UNDOCUMENTED:
813 dev_weight FIXME
814 discovery_slots FIXME
815 discovery_timeout FIXME
816 fast_poll_increase FIXME
817 ip6_queue_maxlen FIXME
818 lap_keepalive_time FIXME
819 lo_cong FIXME
820 max_baud_rate FIXME
821 max_dgram_qlen FIXME
822 max_noreply_time FIXME
823 max_tx_data_size FIXME
824 max_tx_window FIXME
825 min_tx_turn_time FIXME
826 mod_cong FIXME
827 no_cong FIXME
828 no_cong_thresh FIXME
829 slot_timeout FIXME
830 warn_noreply_time FIXME
832 $Id: ip-sysctl.txt,v 1.20 2001/12/13 09:00:18 davem Exp $