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Commit | Line | Data |
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1da177e4 LT |
1 | /proc/sys/net/ipv4/* Variables: |
2 | ||
3 | ip_forward - BOOLEAN | |
4 | 0 - disabled (default) | |
e18f5feb | 5 | not 0 - enabled |
1da177e4 LT |
6 | |
7 | Forward Packets between interfaces. | |
8 | ||
9 | This variable is special, its change resets all configuration | |
10 | parameters to their default state (RFC1122 for hosts, RFC1812 | |
11 | for routers) | |
12 | ||
13 | ip_default_ttl - INTEGER | |
cc6f02dd ED |
14 | Default value of TTL field (Time To Live) for outgoing (but not |
15 | forwarded) IP packets. Should be between 1 and 255 inclusive. | |
16 | Default: 64 (as recommended by RFC1700) | |
1da177e4 LT |
17 | |
18 | ip_no_pmtu_disc - BOOLEAN | |
19 | Disable Path MTU Discovery. | |
20 | default FALSE | |
21 | ||
22 | min_pmtu - INTEGER | |
23 | default 562 - minimum discovered Path MTU | |
24 | ||
cbaf087a BG |
25 | route/max_size - INTEGER |
26 | Maximum number of routes allowed in the kernel. Increase | |
27 | this when using large numbers of interfaces and/or routes. | |
28 | ||
29 | neigh/default/gc_thresh3 - INTEGER | |
30 | Maximum number of neighbor entries allowed. Increase this | |
31 | when using large numbers of interfaces and when communicating | |
32 | with large numbers of directly-connected peers. | |
33 | ||
1da177e4 LT |
34 | mtu_expires - INTEGER |
35 | Time, in seconds, that cached PMTU information is kept. | |
36 | ||
37 | min_adv_mss - INTEGER | |
38 | The advertised MSS depends on the first hop route MTU, but will | |
39 | never be lower than this setting. | |
40 | ||
1080d709 NH |
41 | rt_cache_rebuild_count - INTEGER |
42 | The per net-namespace route cache emergency rebuild threshold. | |
43 | Any net-namespace having its route cache rebuilt due to | |
44 | a hash bucket chain being too long more than this many times | |
45 | will have its route caching disabled | |
46 | ||
1da177e4 LT |
47 | IP Fragmentation: |
48 | ||
49 | ipfrag_high_thresh - INTEGER | |
e18f5feb | 50 | Maximum memory used to reassemble IP fragments. When |
1da177e4 LT |
51 | ipfrag_high_thresh bytes of memory is allocated for this purpose, |
52 | the fragment handler will toss packets until ipfrag_low_thresh | |
53 | is reached. | |
e18f5feb | 54 | |
1da177e4 | 55 | ipfrag_low_thresh - INTEGER |
e18f5feb | 56 | See ipfrag_high_thresh |
1da177e4 LT |
57 | |
58 | ipfrag_time - INTEGER | |
e18f5feb | 59 | Time in seconds to keep an IP fragment in memory. |
1da177e4 LT |
60 | |
61 | ipfrag_secret_interval - INTEGER | |
e18f5feb | 62 | Regeneration interval (in seconds) of the hash secret (or lifetime |
1da177e4 LT |
63 | for the hash secret) for IP fragments. |
64 | Default: 600 | |
65 | ||
89cee8b1 | 66 | ipfrag_max_dist - INTEGER |
e18f5feb JDB |
67 | ipfrag_max_dist is a non-negative integer value which defines the |
68 | maximum "disorder" which is allowed among fragments which share a | |
69 | common IP source address. Note that reordering of packets is | |
70 | not unusual, but if a large number of fragments arrive from a source | |
71 | IP address while a particular fragment queue remains incomplete, it | |
72 | probably indicates that one or more fragments belonging to that queue | |
73 | have been lost. When ipfrag_max_dist is positive, an additional check | |
74 | is done on fragments before they are added to a reassembly queue - if | |
75 | ipfrag_max_dist (or more) fragments have arrived from a particular IP | |
76 | address between additions to any IP fragment queue using that source | |
77 | address, it's presumed that one or more fragments in the queue are | |
78 | lost. The existing fragment queue will be dropped, and a new one | |
89cee8b1 HX |
79 | started. An ipfrag_max_dist value of zero disables this check. |
80 | ||
81 | Using a very small value, e.g. 1 or 2, for ipfrag_max_dist can | |
82 | result in unnecessarily dropping fragment queues when normal | |
e18f5feb JDB |
83 | reordering of packets occurs, which could lead to poor application |
84 | performance. Using a very large value, e.g. 50000, increases the | |
85 | likelihood of incorrectly reassembling IP fragments that originate | |
89cee8b1 HX |
86 | from different IP datagrams, which could result in data corruption. |
87 | Default: 64 | |
88 | ||
1da177e4 LT |
89 | INET peer storage: |
90 | ||
91 | inet_peer_threshold - INTEGER | |
e18f5feb | 92 | The approximate size of the storage. Starting from this threshold |
1da177e4 LT |
93 | entries will be thrown aggressively. This threshold also determines |
94 | entries' time-to-live and time intervals between garbage collection | |
95 | passes. More entries, less time-to-live, less GC interval. | |
96 | ||
97 | inet_peer_minttl - INTEGER | |
98 | Minimum time-to-live of entries. Should be enough to cover fragment | |
99 | time-to-live on the reassembling side. This minimum time-to-live is | |
100 | guaranteed if the pool size is less than inet_peer_threshold. | |
77a538d5 | 101 | Measured in seconds. |
1da177e4 LT |
102 | |
103 | inet_peer_maxttl - INTEGER | |
104 | Maximum time-to-live of entries. Unused entries will expire after | |
105 | this period of time if there is no memory pressure on the pool (i.e. | |
106 | when the number of entries in the pool is very small). | |
77a538d5 | 107 | Measured in seconds. |
1da177e4 LT |
108 | |
109 | inet_peer_gc_mintime - INTEGER | |
110 | Minimum interval between garbage collection passes. This interval is | |
111 | in effect under high memory pressure on the pool. | |
77a538d5 | 112 | Measured in seconds. |
1da177e4 LT |
113 | |
114 | inet_peer_gc_maxtime - INTEGER | |
115 | Minimum interval between garbage collection passes. This interval is | |
116 | in effect under low (or absent) memory pressure on the pool. | |
77a538d5 | 117 | Measured in seconds. |
1da177e4 | 118 | |
e18f5feb | 119 | TCP variables: |
1da177e4 | 120 | |
ef56e622 SH |
121 | somaxconn - INTEGER |
122 | Limit of socket listen() backlog, known in userspace as SOMAXCONN. | |
123 | Defaults to 128. See also tcp_max_syn_backlog for additional tuning | |
124 | for TCP sockets. | |
125 | ||
9772efb9 | 126 | tcp_abc - INTEGER |
b3a8a40d SH |
127 | Controls Appropriate Byte Count (ABC) defined in RFC3465. |
128 | ABC is a way of increasing congestion window (cwnd) more slowly | |
129 | in response to partial acknowledgments. | |
130 | Possible values are: | |
131 | 0 increase cwnd once per acknowledgment (no ABC) | |
132 | 1 increase cwnd once per acknowledgment of full sized segment | |
133 | 2 allow increase cwnd by two if acknowledgment is | |
134 | of two segments to compensate for delayed acknowledgments. | |
135 | Default: 0 (off) | |
9772efb9 | 136 | |
ef56e622 SH |
137 | tcp_abort_on_overflow - BOOLEAN |
138 | If listening service is too slow to accept new connections, | |
139 | reset them. Default state is FALSE. It means that if overflow | |
140 | occurred due to a burst, connection will recover. Enable this | |
141 | option _only_ if you are really sure that listening daemon | |
142 | cannot be tuned to accept connections faster. Enabling this | |
143 | option can harm clients of your server. | |
1da177e4 | 144 | |
ef56e622 SH |
145 | tcp_adv_win_scale - INTEGER |
146 | Count buffering overhead as bytes/2^tcp_adv_win_scale | |
147 | (if tcp_adv_win_scale > 0) or bytes-bytes/2^(-tcp_adv_win_scale), | |
148 | if it is <= 0. | |
0147fc05 | 149 | Possible values are [-31, 31], inclusive. |
ef56e622 | 150 | Default: 2 |
1da177e4 | 151 | |
ef56e622 SH |
152 | tcp_allowed_congestion_control - STRING |
153 | Show/set the congestion control choices available to non-privileged | |
154 | processes. The list is a subset of those listed in | |
155 | tcp_available_congestion_control. | |
156 | Default is "reno" and the default setting (tcp_congestion_control). | |
1da177e4 | 157 | |
ef56e622 SH |
158 | tcp_app_win - INTEGER |
159 | Reserve max(window/2^tcp_app_win, mss) of window for application | |
160 | buffer. Value 0 is special, it means that nothing is reserved. | |
161 | Default: 31 | |
1da177e4 | 162 | |
ef56e622 SH |
163 | tcp_available_congestion_control - STRING |
164 | Shows the available congestion control choices that are registered. | |
165 | More congestion control algorithms may be available as modules, | |
166 | but not loaded. | |
1da177e4 | 167 | |
71599cd1 | 168 | tcp_base_mss - INTEGER |
4edc2f34 SH |
169 | The initial value of search_low to be used by the packetization layer |
170 | Path MTU discovery (MTU probing). If MTU probing is enabled, | |
171 | this is the initial MSS used by the connection. | |
71599cd1 | 172 | |
ef56e622 SH |
173 | tcp_congestion_control - STRING |
174 | Set the congestion control algorithm to be used for new | |
175 | connections. The algorithm "reno" is always available, but | |
176 | additional choices may be available based on kernel configuration. | |
177 | Default is set as part of kernel configuration. | |
1da177e4 | 178 | |
519855c5 WAS |
179 | tcp_cookie_size - INTEGER |
180 | Default size of TCP Cookie Transactions (TCPCT) option, that may be | |
181 | overridden on a per socket basis by the TCPCT socket option. | |
182 | Values greater than the maximum (16) are interpreted as the maximum. | |
183 | Values greater than zero and less than the minimum (8) are interpreted | |
184 | as the minimum. Odd values are interpreted as the next even value. | |
185 | Default: 0 (off). | |
186 | ||
ef56e622 SH |
187 | tcp_dsack - BOOLEAN |
188 | Allows TCP to send "duplicate" SACKs. | |
1da177e4 | 189 | |
34a6ef38 | 190 | tcp_ecn - INTEGER |
255cac91 IJ |
191 | Enable Explicit Congestion Notification (ECN) in TCP. ECN is only |
192 | used when both ends of the TCP flow support it. It is useful to | |
193 | avoid losses due to congestion (when the bottleneck router supports | |
194 | ECN). | |
195 | Possible values are: | |
196 | 0 disable ECN | |
197 | 1 ECN enabled | |
198 | 2 Only server-side ECN enabled. If the other end does | |
199 | not support ECN, behavior is like with ECN disabled. | |
200 | Default: 2 | |
ef56e622 SH |
201 | |
202 | tcp_fack - BOOLEAN | |
203 | Enable FACK congestion avoidance and fast retransmission. | |
204 | The value is not used, if tcp_sack is not enabled. | |
1da177e4 LT |
205 | |
206 | tcp_fin_timeout - INTEGER | |
207 | Time to hold socket in state FIN-WAIT-2, if it was closed | |
208 | by our side. Peer can be broken and never close its side, | |
209 | or even died unexpectedly. Default value is 60sec. | |
210 | Usual value used in 2.2 was 180 seconds, you may restore | |
211 | it, but remember that if your machine is even underloaded WEB server, | |
212 | you risk to overflow memory with kilotons of dead sockets, | |
213 | FIN-WAIT-2 sockets are less dangerous than FIN-WAIT-1, | |
214 | because they eat maximum 1.5K of memory, but they tend | |
215 | to live longer. Cf. tcp_max_orphans. | |
216 | ||
89808060 | 217 | tcp_frto - INTEGER |
cd99889c IJ |
218 | Enables Forward RTO-Recovery (F-RTO) defined in RFC4138. |
219 | F-RTO is an enhanced recovery algorithm for TCP retransmission | |
ef56e622 SH |
220 | timeouts. It is particularly beneficial in wireless environments |
221 | where packet loss is typically due to random radio interference | |
564262c1 | 222 | rather than intermediate router congestion. F-RTO is sender-side |
4edc2f34 SH |
223 | only modification. Therefore it does not require any support from |
224 | the peer. | |
225 | ||
cd99889c IJ |
226 | If set to 1, basic version is enabled. 2 enables SACK enhanced |
227 | F-RTO if flow uses SACK. The basic version can be used also when | |
564262c1 | 228 | SACK is in use though scenario(s) with it exists where F-RTO |
cd99889c IJ |
229 | interacts badly with the packet counting of the SACK enabled TCP |
230 | flow. | |
1da177e4 | 231 | |
89808060 IJ |
232 | tcp_frto_response - INTEGER |
233 | When F-RTO has detected that a TCP retransmission timeout was | |
234 | spurious (i.e, the timeout would have been avoided had TCP set a | |
235 | longer retransmission timeout), TCP has several options what to do | |
236 | next. Possible values are: | |
237 | 0 Rate halving based; a smooth and conservative response, | |
238 | results in halved cwnd and ssthresh after one RTT | |
239 | 1 Very conservative response; not recommended because even | |
240 | though being valid, it interacts poorly with the rest of | |
241 | Linux TCP, halves cwnd and ssthresh immediately | |
242 | 2 Aggressive response; undoes congestion control measures | |
243 | that are now known to be unnecessary (ignoring the | |
244 | possibility of a lost retransmission that would require | |
245 | TCP to be more cautious), cwnd and ssthresh are restored | |
246 | to the values prior timeout | |
247 | Default: 0 (rate halving based) | |
248 | ||
ef56e622 SH |
249 | tcp_keepalive_time - INTEGER |
250 | How often TCP sends out keepalive messages when keepalive is enabled. | |
251 | Default: 2hours. | |
1da177e4 | 252 | |
ef56e622 SH |
253 | tcp_keepalive_probes - INTEGER |
254 | How many keepalive probes TCP sends out, until it decides that the | |
255 | connection is broken. Default value: 9. | |
256 | ||
257 | tcp_keepalive_intvl - INTEGER | |
258 | How frequently the probes are send out. Multiplied by | |
259 | tcp_keepalive_probes it is time to kill not responding connection, | |
260 | after probes started. Default value: 75sec i.e. connection | |
261 | will be aborted after ~11 minutes of retries. | |
262 | ||
263 | tcp_low_latency - BOOLEAN | |
264 | If set, the TCP stack makes decisions that prefer lower | |
265 | latency as opposed to higher throughput. By default, this | |
266 | option is not set meaning that higher throughput is preferred. | |
267 | An example of an application where this default should be | |
268 | changed would be a Beowulf compute cluster. | |
269 | Default: 0 | |
1da177e4 LT |
270 | |
271 | tcp_max_orphans - INTEGER | |
272 | Maximal number of TCP sockets not attached to any user file handle, | |
273 | held by system. If this number is exceeded orphaned connections are | |
274 | reset immediately and warning is printed. This limit exists | |
275 | only to prevent simple DoS attacks, you _must_ not rely on this | |
276 | or lower the limit artificially, but rather increase it | |
277 | (probably, after increasing installed memory), | |
278 | if network conditions require more than default value, | |
279 | and tune network services to linger and kill such states | |
280 | more aggressively. Let me to remind again: each orphan eats | |
281 | up to ~64K of unswappable memory. | |
282 | ||
81146ec1 IJ |
283 | tcp_max_ssthresh - INTEGER |
284 | Limited Slow-Start for TCP with large congestion windows (cwnd) defined in | |
285 | RFC3742. Limited slow-start is a mechanism to limit growth of the cwnd | |
286 | on the region where cwnd is larger than tcp_max_ssthresh. TCP increases cwnd | |
287 | by at most tcp_max_ssthresh segments, and by at least tcp_max_ssthresh/2 | |
288 | segments per RTT when the cwnd is above tcp_max_ssthresh. | |
289 | If TCP connection increased cwnd to thousands (or tens of thousands) segments, | |
290 | and thousands of packets were being dropped during slow-start, you can set | |
291 | tcp_max_ssthresh to improve performance for new TCP connection. | |
292 | Default: 0 (off) | |
293 | ||
1da177e4 LT |
294 | tcp_max_syn_backlog - INTEGER |
295 | Maximal number of remembered connection requests, which are | |
296 | still did not receive an acknowledgment from connecting client. | |
297 | Default value is 1024 for systems with more than 128Mb of memory, | |
298 | and 128 for low memory machines. If server suffers of overload, | |
299 | try to increase this number. | |
300 | ||
ef56e622 SH |
301 | tcp_max_tw_buckets - INTEGER |
302 | Maximal number of timewait sockets held by system simultaneously. | |
303 | If this number is exceeded time-wait socket is immediately destroyed | |
304 | and warning is printed. This limit exists only to prevent | |
305 | simple DoS attacks, you _must_ not lower the limit artificially, | |
306 | but rather increase it (probably, after increasing installed memory), | |
307 | if network conditions require more than default value. | |
1da177e4 | 308 | |
ef56e622 SH |
309 | tcp_mem - vector of 3 INTEGERs: min, pressure, max |
310 | min: below this number of pages TCP is not bothered about its | |
311 | memory appetite. | |
1da177e4 | 312 | |
ef56e622 SH |
313 | pressure: when amount of memory allocated by TCP exceeds this number |
314 | of pages, TCP moderates its memory consumption and enters memory | |
315 | pressure mode, which is exited when memory consumption falls | |
316 | under "min". | |
1da177e4 | 317 | |
ef56e622 | 318 | max: number of pages allowed for queueing by all TCP sockets. |
1da177e4 | 319 | |
ef56e622 SH |
320 | Defaults are calculated at boot time from amount of available |
321 | memory. | |
1da177e4 | 322 | |
71599cd1 | 323 | tcp_moderate_rcvbuf - BOOLEAN |
4edc2f34 | 324 | If set, TCP performs receive buffer auto-tuning, attempting to |
71599cd1 JH |
325 | automatically size the buffer (no greater than tcp_rmem[2]) to |
326 | match the size required by the path for full throughput. Enabled by | |
327 | default. | |
328 | ||
329 | tcp_mtu_probing - INTEGER | |
330 | Controls TCP Packetization-Layer Path MTU Discovery. Takes three | |
331 | values: | |
332 | 0 - Disabled | |
333 | 1 - Disabled by default, enabled when an ICMP black hole detected | |
334 | 2 - Always enabled, use initial MSS of tcp_base_mss. | |
335 | ||
336 | tcp_no_metrics_save - BOOLEAN | |
337 | By default, TCP saves various connection metrics in the route cache | |
338 | when the connection closes, so that connections established in the | |
339 | near future can use these to set initial conditions. Usually, this | |
340 | increases overall performance, but may sometimes cause performance | |
0f035b8e | 341 | degradation. If set, TCP will not cache metrics on closing |
71599cd1 JH |
342 | connections. |
343 | ||
ef56e622 | 344 | tcp_orphan_retries - INTEGER |
5d789229 DL |
345 | This value influences the timeout of a locally closed TCP connection, |
346 | when RTO retransmissions remain unacknowledged. | |
347 | See tcp_retries2 for more details. | |
348 | ||
06b8fc5d | 349 | The default value is 8. |
5d789229 | 350 | If your machine is a loaded WEB server, |
ef56e622 SH |
351 | you should think about lowering this value, such sockets |
352 | may consume significant resources. Cf. tcp_max_orphans. | |
1da177e4 LT |
353 | |
354 | tcp_reordering - INTEGER | |
355 | Maximal reordering of packets in a TCP stream. | |
e18f5feb | 356 | Default: 3 |
1da177e4 LT |
357 | |
358 | tcp_retrans_collapse - BOOLEAN | |
359 | Bug-to-bug compatibility with some broken printers. | |
360 | On retransmit try to send bigger packets to work around bugs in | |
361 | certain TCP stacks. | |
362 | ||
ef56e622 | 363 | tcp_retries1 - INTEGER |
5d789229 DL |
364 | This value influences the time, after which TCP decides, that |
365 | something is wrong due to unacknowledged RTO retransmissions, | |
366 | and reports this suspicion to the network layer. | |
367 | See tcp_retries2 for more details. | |
368 | ||
369 | RFC 1122 recommends at least 3 retransmissions, which is the | |
370 | default. | |
1da177e4 | 371 | |
ef56e622 | 372 | tcp_retries2 - INTEGER |
5d789229 DL |
373 | This value influences the timeout of an alive TCP connection, |
374 | when RTO retransmissions remain unacknowledged. | |
375 | Given a value of N, a hypothetical TCP connection following | |
376 | exponential backoff with an initial RTO of TCP_RTO_MIN would | |
377 | retransmit N times before killing the connection at the (N+1)th RTO. | |
378 | ||
379 | The default value of 15 yields a hypothetical timeout of 924.6 | |
380 | seconds and is a lower bound for the effective timeout. | |
381 | TCP will effectively time out at the first RTO which exceeds the | |
382 | hypothetical timeout. | |
383 | ||
384 | RFC 1122 recommends at least 100 seconds for the timeout, | |
385 | which corresponds to a value of at least 8. | |
1da177e4 | 386 | |
ef56e622 SH |
387 | tcp_rfc1337 - BOOLEAN |
388 | If set, the TCP stack behaves conforming to RFC1337. If unset, | |
389 | we are not conforming to RFC, but prevent TCP TIME_WAIT | |
390 | assassination. | |
391 | Default: 0 | |
1da177e4 LT |
392 | |
393 | tcp_rmem - vector of 3 INTEGERs: min, default, max | |
394 | min: Minimal size of receive buffer used by TCP sockets. | |
395 | It is guaranteed to each TCP socket, even under moderate memory | |
396 | pressure. | |
397 | Default: 8K | |
398 | ||
53025f5e | 399 | default: initial size of receive buffer used by TCP sockets. |
1da177e4 LT |
400 | This value overrides net.core.rmem_default used by other protocols. |
401 | Default: 87380 bytes. This value results in window of 65535 with | |
402 | default setting of tcp_adv_win_scale and tcp_app_win:0 and a bit | |
403 | less for default tcp_app_win. See below about these variables. | |
404 | ||
405 | max: maximal size of receive buffer allowed for automatically | |
406 | selected receiver buffers for TCP socket. This value does not override | |
53025f5e BF |
407 | net.core.rmem_max. Calling setsockopt() with SO_RCVBUF disables |
408 | automatic tuning of that socket's receive buffer size, in which | |
409 | case this value is ignored. | |
410 | Default: between 87380B and 4MB, depending on RAM size. | |
1da177e4 | 411 | |
ef56e622 SH |
412 | tcp_sack - BOOLEAN |
413 | Enable select acknowledgments (SACKS). | |
1da177e4 | 414 | |
ef56e622 SH |
415 | tcp_slow_start_after_idle - BOOLEAN |
416 | If set, provide RFC2861 behavior and time out the congestion | |
417 | window after an idle period. An idle period is defined at | |
418 | the current RTO. If unset, the congestion window will not | |
419 | be timed out after an idle period. | |
420 | Default: 1 | |
1da177e4 | 421 | |
ef56e622 | 422 | tcp_stdurg - BOOLEAN |
4edc2f34 | 423 | Use the Host requirements interpretation of the TCP urgent pointer field. |
ef56e622 SH |
424 | Most hosts use the older BSD interpretation, so if you turn this on |
425 | Linux might not communicate correctly with them. | |
426 | Default: FALSE | |
1da177e4 | 427 | |
ef56e622 SH |
428 | tcp_synack_retries - INTEGER |
429 | Number of times SYNACKs for a passive TCP connection attempt will | |
430 | be retransmitted. Should not be higher than 255. Default value | |
431 | is 5, which corresponds to ~180seconds. | |
1da177e4 | 432 | |
ef56e622 SH |
433 | tcp_syncookies - BOOLEAN |
434 | Only valid when the kernel was compiled with CONFIG_SYNCOOKIES | |
435 | Send out syncookies when the syn backlog queue of a socket | |
4edc2f34 | 436 | overflows. This is to prevent against the common 'SYN flood attack' |
ef56e622 | 437 | Default: FALSE |
1da177e4 | 438 | |
ef56e622 SH |
439 | Note, that syncookies is fallback facility. |
440 | It MUST NOT be used to help highly loaded servers to stand | |
4edc2f34 | 441 | against legal connection rate. If you see SYN flood warnings |
ef56e622 SH |
442 | in your logs, but investigation shows that they occur |
443 | because of overload with legal connections, you should tune | |
444 | another parameters until this warning disappear. | |
445 | See: tcp_max_syn_backlog, tcp_synack_retries, tcp_abort_on_overflow. | |
1da177e4 | 446 | |
ef56e622 SH |
447 | syncookies seriously violate TCP protocol, do not allow |
448 | to use TCP extensions, can result in serious degradation | |
449 | of some services (f.e. SMTP relaying), visible not by you, | |
450 | but your clients and relays, contacting you. While you see | |
4edc2f34 | 451 | SYN flood warnings in logs not being really flooded, your server |
ef56e622 | 452 | is seriously misconfigured. |
1da177e4 | 453 | |
ef56e622 SH |
454 | tcp_syn_retries - INTEGER |
455 | Number of times initial SYNs for an active TCP connection attempt | |
456 | will be retransmitted. Should not be higher than 255. Default value | |
457 | is 5, which corresponds to ~180seconds. | |
458 | ||
459 | tcp_timestamps - BOOLEAN | |
460 | Enable timestamps as defined in RFC1323. | |
1da177e4 | 461 | |
1da177e4 | 462 | tcp_tso_win_divisor - INTEGER |
ef56e622 SH |
463 | This allows control over what percentage of the congestion window |
464 | can be consumed by a single TSO frame. | |
465 | The setting of this parameter is a choice between burstiness and | |
466 | building larger TSO frames. | |
467 | Default: 3 | |
1da177e4 | 468 | |
ef56e622 SH |
469 | tcp_tw_recycle - BOOLEAN |
470 | Enable fast recycling TIME-WAIT sockets. Default value is 0. | |
471 | It should not be changed without advice/request of technical | |
472 | experts. | |
1da177e4 | 473 | |
ef56e622 SH |
474 | tcp_tw_reuse - BOOLEAN |
475 | Allow to reuse TIME-WAIT sockets for new connections when it is | |
476 | safe from protocol viewpoint. Default value is 0. | |
477 | It should not be changed without advice/request of technical | |
478 | experts. | |
ce7bc3bf | 479 | |
ef56e622 SH |
480 | tcp_window_scaling - BOOLEAN |
481 | Enable window scaling as defined in RFC1323. | |
3ff825b2 | 482 | |
ef56e622 | 483 | tcp_wmem - vector of 3 INTEGERs: min, default, max |
53025f5e | 484 | min: Amount of memory reserved for send buffers for TCP sockets. |
ef56e622 SH |
485 | Each TCP socket has rights to use it due to fact of its birth. |
486 | Default: 4K | |
9d7bcfc6 | 487 | |
53025f5e BF |
488 | default: initial size of send buffer used by TCP sockets. This |
489 | value overrides net.core.wmem_default used by other protocols. | |
490 | It is usually lower than net.core.wmem_default. | |
ef56e622 SH |
491 | Default: 16K |
492 | ||
53025f5e BF |
493 | max: Maximal amount of memory allowed for automatically tuned |
494 | send buffers for TCP sockets. This value does not override | |
495 | net.core.wmem_max. Calling setsockopt() with SO_SNDBUF disables | |
496 | automatic tuning of that socket's send buffer size, in which case | |
497 | this value is ignored. | |
498 | Default: between 64K and 4MB, depending on RAM size. | |
1da177e4 | 499 | |
15d99e02 RJ |
500 | tcp_workaround_signed_windows - BOOLEAN |
501 | If set, assume no receipt of a window scaling option means the | |
502 | remote TCP is broken and treats the window as a signed quantity. | |
503 | If unset, assume the remote TCP is not broken even if we do | |
504 | not receive a window scaling option from them. | |
505 | Default: 0 | |
506 | ||
72d0b7a8 CL |
507 | tcp_dma_copybreak - INTEGER |
508 | Lower limit, in bytes, of the size of socket reads that will be | |
509 | offloaded to a DMA copy engine, if one is present in the system | |
510 | and CONFIG_NET_DMA is enabled. | |
511 | Default: 4096 | |
512 | ||
36e31b0a AP |
513 | tcp_thin_linear_timeouts - BOOLEAN |
514 | Enable dynamic triggering of linear timeouts for thin streams. | |
515 | If set, a check is performed upon retransmission by timeout to | |
516 | determine if the stream is thin (less than 4 packets in flight). | |
517 | As long as the stream is found to be thin, up to 6 linear | |
518 | timeouts may be performed before exponential backoff mode is | |
519 | initiated. This improves retransmission latency for | |
520 | non-aggressive thin streams, often found to be time-dependent. | |
521 | For more information on thin streams, see | |
522 | Documentation/networking/tcp-thin.txt | |
523 | Default: 0 | |
524 | ||
7e380175 AP |
525 | tcp_thin_dupack - BOOLEAN |
526 | Enable dynamic triggering of retransmissions after one dupACK | |
527 | for thin streams. If set, a check is performed upon reception | |
528 | of a dupACK to determine if the stream is thin (less than 4 | |
529 | packets in flight). As long as the stream is found to be thin, | |
530 | data is retransmitted on the first received dupACK. This | |
531 | improves retransmission latency for non-aggressive thin | |
532 | streams, often found to be time-dependent. | |
533 | For more information on thin streams, see | |
534 | Documentation/networking/tcp-thin.txt | |
535 | Default: 0 | |
536 | ||
95766fff HA |
537 | UDP variables: |
538 | ||
539 | udp_mem - vector of 3 INTEGERs: min, pressure, max | |
540 | Number of pages allowed for queueing by all UDP sockets. | |
541 | ||
542 | min: Below this number of pages UDP is not bothered about its | |
543 | memory appetite. When amount of memory allocated by UDP exceeds | |
544 | this number, UDP starts to moderate memory usage. | |
545 | ||
546 | pressure: This value was introduced to follow format of tcp_mem. | |
547 | ||
548 | max: Number of pages allowed for queueing by all UDP sockets. | |
549 | ||
550 | Default is calculated at boot time from amount of available memory. | |
551 | ||
552 | udp_rmem_min - INTEGER | |
553 | Minimal size of receive buffer used by UDP sockets in moderation. | |
554 | Each UDP socket is able to use the size for receiving data, even if | |
555 | total pages of UDP sockets exceed udp_mem pressure. The unit is byte. | |
556 | Default: 4096 | |
557 | ||
558 | udp_wmem_min - INTEGER | |
559 | Minimal size of send buffer used by UDP sockets in moderation. | |
560 | Each UDP socket is able to use the size for sending data, even if | |
561 | total pages of UDP sockets exceed udp_mem pressure. The unit is byte. | |
562 | Default: 4096 | |
563 | ||
8802f616 PM |
564 | CIPSOv4 Variables: |
565 | ||
566 | cipso_cache_enable - BOOLEAN | |
567 | If set, enable additions to and lookups from the CIPSO label mapping | |
568 | cache. If unset, additions are ignored and lookups always result in a | |
569 | miss. However, regardless of the setting the cache is still | |
570 | invalidated when required when means you can safely toggle this on and | |
571 | off and the cache will always be "safe". | |
572 | Default: 1 | |
573 | ||
574 | cipso_cache_bucket_size - INTEGER | |
575 | The CIPSO label cache consists of a fixed size hash table with each | |
576 | hash bucket containing a number of cache entries. This variable limits | |
577 | the number of entries in each hash bucket; the larger the value the | |
578 | more CIPSO label mappings that can be cached. When the number of | |
579 | entries in a given hash bucket reaches this limit adding new entries | |
580 | causes the oldest entry in the bucket to be removed to make room. | |
581 | Default: 10 | |
582 | ||
583 | cipso_rbm_optfmt - BOOLEAN | |
584 | Enable the "Optimized Tag 1 Format" as defined in section 3.4.2.6 of | |
585 | the CIPSO draft specification (see Documentation/netlabel for details). | |
586 | This means that when set the CIPSO tag will be padded with empty | |
587 | categories in order to make the packet data 32-bit aligned. | |
588 | Default: 0 | |
589 | ||
590 | cipso_rbm_structvalid - BOOLEAN | |
591 | If set, do a very strict check of the CIPSO option when | |
592 | ip_options_compile() is called. If unset, relax the checks done during | |
593 | ip_options_compile(). Either way is "safe" as errors are caught else | |
594 | where in the CIPSO processing code but setting this to 0 (False) should | |
595 | result in less work (i.e. it should be faster) but could cause problems | |
596 | with other implementations that require strict checking. | |
597 | Default: 0 | |
598 | ||
1da177e4 LT |
599 | IP Variables: |
600 | ||
601 | ip_local_port_range - 2 INTEGERS | |
602 | Defines the local port range that is used by TCP and UDP to | |
e18f5feb | 603 | choose the local port. The first number is the first, the |
1da177e4 LT |
604 | second the last local port number. Default value depends on |
605 | amount of memory available on the system: | |
606 | > 128Mb 32768-61000 | |
607 | < 128Mb 1024-4999 or even less. | |
608 | This number defines number of active connections, which this | |
609 | system can issue simultaneously to systems not supporting | |
610 | TCP extensions (timestamps). With tcp_tw_recycle enabled | |
611 | (i.e. by default) range 1024-4999 is enough to issue up to | |
612 | 2000 connections per second to systems supporting timestamps. | |
613 | ||
e3826f1e AW |
614 | ip_local_reserved_ports - list of comma separated ranges |
615 | Specify the ports which are reserved for known third-party | |
616 | applications. These ports will not be used by automatic port | |
617 | assignments (e.g. when calling connect() or bind() with port | |
618 | number 0). Explicit port allocation behavior is unchanged. | |
619 | ||
620 | The format used for both input and output is a comma separated | |
621 | list of ranges (e.g. "1,2-4,10-10" for ports 1, 2, 3, 4 and | |
622 | 10). Writing to the file will clear all previously reserved | |
623 | ports and update the current list with the one given in the | |
624 | input. | |
625 | ||
626 | Note that ip_local_port_range and ip_local_reserved_ports | |
627 | settings are independent and both are considered by the kernel | |
628 | when determining which ports are available for automatic port | |
629 | assignments. | |
630 | ||
631 | You can reserve ports which are not in the current | |
632 | ip_local_port_range, e.g.: | |
633 | ||
634 | $ cat /proc/sys/net/ipv4/ip_local_port_range | |
635 | 32000 61000 | |
636 | $ cat /proc/sys/net/ipv4/ip_local_reserved_ports | |
637 | 8080,9148 | |
638 | ||
639 | although this is redundant. However such a setting is useful | |
640 | if later the port range is changed to a value that will | |
641 | include the reserved ports. | |
642 | ||
643 | Default: Empty | |
644 | ||
1da177e4 LT |
645 | ip_nonlocal_bind - BOOLEAN |
646 | If set, allows processes to bind() to non-local IP addresses, | |
647 | which can be quite useful - but may break some applications. | |
648 | Default: 0 | |
649 | ||
650 | ip_dynaddr - BOOLEAN | |
651 | If set non-zero, enables support for dynamic addresses. | |
652 | If set to a non-zero value larger than 1, a kernel log | |
653 | message will be printed when dynamic address rewriting | |
654 | occurs. | |
655 | Default: 0 | |
656 | ||
657 | icmp_echo_ignore_all - BOOLEAN | |
7ce31246 DM |
658 | If set non-zero, then the kernel will ignore all ICMP ECHO |
659 | requests sent to it. | |
660 | Default: 0 | |
661 | ||
1da177e4 | 662 | icmp_echo_ignore_broadcasts - BOOLEAN |
7ce31246 DM |
663 | If set non-zero, then the kernel will ignore all ICMP ECHO and |
664 | TIMESTAMP requests sent to it via broadcast/multicast. | |
665 | Default: 1 | |
1da177e4 LT |
666 | |
667 | icmp_ratelimit - INTEGER | |
668 | Limit the maximal rates for sending ICMP packets whose type matches | |
669 | icmp_ratemask (see below) to specific targets. | |
6dbf4bca SH |
670 | 0 to disable any limiting, |
671 | otherwise the minimal space between responses in milliseconds. | |
672 | Default: 1000 | |
1da177e4 LT |
673 | |
674 | icmp_ratemask - INTEGER | |
675 | Mask made of ICMP types for which rates are being limited. | |
676 | Significant bits: IHGFEDCBA9876543210 | |
677 | Default mask: 0000001100000011000 (6168) | |
678 | ||
679 | Bit definitions (see include/linux/icmp.h): | |
680 | 0 Echo Reply | |
681 | 3 Destination Unreachable * | |
682 | 4 Source Quench * | |
683 | 5 Redirect | |
684 | 8 Echo Request | |
685 | B Time Exceeded * | |
686 | C Parameter Problem * | |
687 | D Timestamp Request | |
688 | E Timestamp Reply | |
689 | F Info Request | |
690 | G Info Reply | |
691 | H Address Mask Request | |
692 | I Address Mask Reply | |
693 | ||
694 | * These are rate limited by default (see default mask above) | |
695 | ||
696 | icmp_ignore_bogus_error_responses - BOOLEAN | |
697 | Some routers violate RFC1122 by sending bogus responses to broadcast | |
698 | frames. Such violations are normally logged via a kernel warning. | |
699 | If this is set to TRUE, the kernel will not give such warnings, which | |
700 | will avoid log file clutter. | |
701 | Default: FALSE | |
702 | ||
95f7daf1 H |
703 | icmp_errors_use_inbound_ifaddr - BOOLEAN |
704 | ||
705 | If zero, icmp error messages are sent with the primary address of | |
706 | the exiting interface. | |
e18f5feb | 707 | |
95f7daf1 H |
708 | If non-zero, the message will be sent with the primary address of |
709 | the interface that received the packet that caused the icmp error. | |
710 | This is the behaviour network many administrators will expect from | |
711 | a router. And it can make debugging complicated network layouts | |
e18f5feb | 712 | much easier. |
95f7daf1 H |
713 | |
714 | Note that if no primary address exists for the interface selected, | |
715 | then the primary address of the first non-loopback interface that | |
d6bc8ac9 | 716 | has one will be used regardless of this setting. |
95f7daf1 H |
717 | |
718 | Default: 0 | |
719 | ||
1da177e4 LT |
720 | igmp_max_memberships - INTEGER |
721 | Change the maximum number of multicast groups we can subscribe to. | |
722 | Default: 20 | |
723 | ||
d67ef35f JE |
724 | Theoretical maximum value is bounded by having to send a membership |
725 | report in a single datagram (i.e. the report can't span multiple | |
726 | datagrams, or risk confusing the switch and leaving groups you don't | |
727 | intend to). | |
1da177e4 | 728 | |
d67ef35f JE |
729 | The number of supported groups 'M' is bounded by the number of group |
730 | report entries you can fit into a single datagram of 65535 bytes. | |
731 | ||
732 | M = 65536-sizeof (ip header)/(sizeof(Group record)) | |
733 | ||
734 | Group records are variable length, with a minimum of 12 bytes. | |
735 | So net.ipv4.igmp_max_memberships should not be set higher than: | |
736 | ||
737 | (65536-24) / 12 = 5459 | |
738 | ||
739 | The value 5459 assumes no IP header options, so in practice | |
740 | this number may be lower. | |
741 | ||
742 | conf/interface/* changes special settings per interface (where | |
743 | "interface" is the name of your network interface) | |
744 | ||
745 | conf/all/* is special, changes the settings for all interfaces | |
1da177e4 LT |
746 | |
747 | log_martians - BOOLEAN | |
748 | Log packets with impossible addresses to kernel log. | |
749 | log_martians for the interface will be enabled if at least one of | |
750 | conf/{all,interface}/log_martians is set to TRUE, | |
751 | it will be disabled otherwise | |
752 | ||
753 | accept_redirects - BOOLEAN | |
754 | Accept ICMP redirect messages. | |
755 | accept_redirects for the interface will be enabled if: | |
e18f5feb JDB |
756 | - both conf/{all,interface}/accept_redirects are TRUE in the case |
757 | forwarding for the interface is enabled | |
1da177e4 | 758 | or |
e18f5feb JDB |
759 | - at least one of conf/{all,interface}/accept_redirects is TRUE in the |
760 | case forwarding for the interface is disabled | |
1da177e4 LT |
761 | accept_redirects for the interface will be disabled otherwise |
762 | default TRUE (host) | |
763 | FALSE (router) | |
764 | ||
765 | forwarding - BOOLEAN | |
766 | Enable IP forwarding on this interface. | |
767 | ||
768 | mc_forwarding - BOOLEAN | |
769 | Do multicast routing. The kernel needs to be compiled with CONFIG_MROUTE | |
770 | and a multicast routing daemon is required. | |
e18f5feb JDB |
771 | conf/all/mc_forwarding must also be set to TRUE to enable multicast |
772 | routing for the interface | |
1da177e4 LT |
773 | |
774 | medium_id - INTEGER | |
775 | Integer value used to differentiate the devices by the medium they | |
776 | are attached to. Two devices can have different id values when | |
777 | the broadcast packets are received only on one of them. | |
778 | The default value 0 means that the device is the only interface | |
779 | to its medium, value of -1 means that medium is not known. | |
e18f5feb | 780 | |
1da177e4 LT |
781 | Currently, it is used to change the proxy_arp behavior: |
782 | the proxy_arp feature is enabled for packets forwarded between | |
783 | two devices attached to different media. | |
784 | ||
785 | proxy_arp - BOOLEAN | |
786 | Do proxy arp. | |
787 | proxy_arp for the interface will be enabled if at least one of | |
788 | conf/{all,interface}/proxy_arp is set to TRUE, | |
789 | it will be disabled otherwise | |
790 | ||
65324144 JDB |
791 | proxy_arp_pvlan - BOOLEAN |
792 | Private VLAN proxy arp. | |
793 | Basically allow proxy arp replies back to the same interface | |
794 | (from which the ARP request/solicitation was received). | |
795 | ||
796 | This is done to support (ethernet) switch features, like RFC | |
797 | 3069, where the individual ports are NOT allowed to | |
798 | communicate with each other, but they are allowed to talk to | |
799 | the upstream router. As described in RFC 3069, it is possible | |
800 | to allow these hosts to communicate through the upstream | |
801 | router by proxy_arp'ing. Don't need to be used together with | |
802 | proxy_arp. | |
803 | ||
804 | This technology is known by different names: | |
805 | In RFC 3069 it is called VLAN Aggregation. | |
806 | Cisco and Allied Telesyn call it Private VLAN. | |
807 | Hewlett-Packard call it Source-Port filtering or port-isolation. | |
808 | Ericsson call it MAC-Forced Forwarding (RFC Draft). | |
809 | ||
1da177e4 LT |
810 | shared_media - BOOLEAN |
811 | Send(router) or accept(host) RFC1620 shared media redirects. | |
812 | Overrides ip_secure_redirects. | |
813 | shared_media for the interface will be enabled if at least one of | |
814 | conf/{all,interface}/shared_media is set to TRUE, | |
815 | it will be disabled otherwise | |
816 | default TRUE | |
817 | ||
818 | secure_redirects - BOOLEAN | |
819 | Accept ICMP redirect messages only for gateways, | |
820 | listed in default gateway list. | |
821 | secure_redirects for the interface will be enabled if at least one of | |
822 | conf/{all,interface}/secure_redirects is set to TRUE, | |
823 | it will be disabled otherwise | |
824 | default TRUE | |
825 | ||
826 | send_redirects - BOOLEAN | |
827 | Send redirects, if router. | |
828 | send_redirects for the interface will be enabled if at least one of | |
829 | conf/{all,interface}/send_redirects is set to TRUE, | |
830 | it will be disabled otherwise | |
831 | Default: TRUE | |
832 | ||
833 | bootp_relay - BOOLEAN | |
834 | Accept packets with source address 0.b.c.d destined | |
835 | not to this host as local ones. It is supposed, that | |
836 | BOOTP relay daemon will catch and forward such packets. | |
837 | conf/all/bootp_relay must also be set to TRUE to enable BOOTP relay | |
838 | for the interface | |
839 | default FALSE | |
840 | Not Implemented Yet. | |
841 | ||
842 | accept_source_route - BOOLEAN | |
843 | Accept packets with SRR option. | |
844 | conf/all/accept_source_route must also be set to TRUE to accept packets | |
845 | with SRR option on the interface | |
846 | default TRUE (router) | |
847 | FALSE (host) | |
848 | ||
8153a10c PM |
849 | accept_local - BOOLEAN |
850 | Accept packets with local source addresses. In combination with | |
851 | suitable routing, this can be used to direct packets between two | |
852 | local interfaces over the wire and have them accepted properly. | |
853 | default FALSE | |
854 | ||
c1cf8422 | 855 | rp_filter - INTEGER |
1da177e4 | 856 | 0 - No source validation. |
c1cf8422 SH |
857 | 1 - Strict mode as defined in RFC3704 Strict Reverse Path |
858 | Each incoming packet is tested against the FIB and if the interface | |
859 | is not the best reverse path the packet check will fail. | |
860 | By default failed packets are discarded. | |
861 | 2 - Loose mode as defined in RFC3704 Loose Reverse Path | |
862 | Each incoming packet's source address is also tested against the FIB | |
863 | and if the source address is not reachable via any interface | |
864 | the packet check will fail. | |
865 | ||
e18f5feb | 866 | Current recommended practice in RFC3704 is to enable strict mode |
bf869c30 | 867 | to prevent IP spoofing from DDos attacks. If using asymmetric routing |
e18f5feb | 868 | or other complicated routing, then loose mode is recommended. |
c1cf8422 | 869 | |
1f5865e7 SW |
870 | The max value from conf/{all,interface}/rp_filter is used |
871 | when doing source validation on the {interface}. | |
1da177e4 LT |
872 | |
873 | Default value is 0. Note that some distributions enable it | |
874 | in startup scripts. | |
875 | ||
876 | arp_filter - BOOLEAN | |
877 | 1 - Allows you to have multiple network interfaces on the same | |
878 | subnet, and have the ARPs for each interface be answered | |
879 | based on whether or not the kernel would route a packet from | |
880 | the ARP'd IP out that interface (therefore you must use source | |
881 | based routing for this to work). In other words it allows control | |
882 | of which cards (usually 1) will respond to an arp request. | |
883 | ||
884 | 0 - (default) The kernel can respond to arp requests with addresses | |
885 | from other interfaces. This may seem wrong but it usually makes | |
886 | sense, because it increases the chance of successful communication. | |
887 | IP addresses are owned by the complete host on Linux, not by | |
888 | particular interfaces. Only for more complex setups like load- | |
889 | balancing, does this behaviour cause problems. | |
890 | ||
891 | arp_filter for the interface will be enabled if at least one of | |
892 | conf/{all,interface}/arp_filter is set to TRUE, | |
893 | it will be disabled otherwise | |
894 | ||
895 | arp_announce - INTEGER | |
896 | Define different restriction levels for announcing the local | |
897 | source IP address from IP packets in ARP requests sent on | |
898 | interface: | |
899 | 0 - (default) Use any local address, configured on any interface | |
900 | 1 - Try to avoid local addresses that are not in the target's | |
901 | subnet for this interface. This mode is useful when target | |
902 | hosts reachable via this interface require the source IP | |
903 | address in ARP requests to be part of their logical network | |
904 | configured on the receiving interface. When we generate the | |
905 | request we will check all our subnets that include the | |
906 | target IP and will preserve the source address if it is from | |
907 | such subnet. If there is no such subnet we select source | |
908 | address according to the rules for level 2. | |
909 | 2 - Always use the best local address for this target. | |
910 | In this mode we ignore the source address in the IP packet | |
911 | and try to select local address that we prefer for talks with | |
912 | the target host. Such local address is selected by looking | |
913 | for primary IP addresses on all our subnets on the outgoing | |
914 | interface that include the target IP address. If no suitable | |
915 | local address is found we select the first local address | |
916 | we have on the outgoing interface or on all other interfaces, | |
917 | with the hope we will receive reply for our request and | |
918 | even sometimes no matter the source IP address we announce. | |
919 | ||
920 | The max value from conf/{all,interface}/arp_announce is used. | |
921 | ||
922 | Increasing the restriction level gives more chance for | |
923 | receiving answer from the resolved target while decreasing | |
924 | the level announces more valid sender's information. | |
925 | ||
926 | arp_ignore - INTEGER | |
927 | Define different modes for sending replies in response to | |
928 | received ARP requests that resolve local target IP addresses: | |
929 | 0 - (default): reply for any local target IP address, configured | |
930 | on any interface | |
931 | 1 - reply only if the target IP address is local address | |
932 | configured on the incoming interface | |
933 | 2 - reply only if the target IP address is local address | |
934 | configured on the incoming interface and both with the | |
935 | sender's IP address are part from same subnet on this interface | |
936 | 3 - do not reply for local addresses configured with scope host, | |
937 | only resolutions for global and link addresses are replied | |
938 | 4-7 - reserved | |
939 | 8 - do not reply for all local addresses | |
940 | ||
941 | The max value from conf/{all,interface}/arp_ignore is used | |
942 | when ARP request is received on the {interface} | |
943 | ||
eefef1cf SH |
944 | arp_notify - BOOLEAN |
945 | Define mode for notification of address and device changes. | |
946 | 0 - (default): do nothing | |
3f8dc236 | 947 | 1 - Generate gratuitous arp requests when device is brought up |
eefef1cf SH |
948 | or hardware address changes. |
949 | ||
c1b1bce8 | 950 | arp_accept - BOOLEAN |
6d955180 OP |
951 | Define behavior for gratuitous ARP frames who's IP is not |
952 | already present in the ARP table: | |
953 | 0 - don't create new entries in the ARP table | |
954 | 1 - create new entries in the ARP table | |
955 | ||
956 | Both replies and requests type gratuitous arp will trigger the | |
957 | ARP table to be updated, if this setting is on. | |
958 | ||
959 | If the ARP table already contains the IP address of the | |
960 | gratuitous arp frame, the arp table will be updated regardless | |
961 | if this setting is on or off. | |
962 | ||
c1b1bce8 | 963 | |
1da177e4 LT |
964 | app_solicit - INTEGER |
965 | The maximum number of probes to send to the user space ARP daemon | |
966 | via netlink before dropping back to multicast probes (see | |
967 | mcast_solicit). Defaults to 0. | |
968 | ||
969 | disable_policy - BOOLEAN | |
970 | Disable IPSEC policy (SPD) for this interface | |
971 | ||
972 | disable_xfrm - BOOLEAN | |
973 | Disable IPSEC encryption on this interface, whatever the policy | |
974 | ||
975 | ||
976 | ||
977 | tag - INTEGER | |
978 | Allows you to write a number, which can be used as required. | |
979 | Default value is 0. | |
980 | ||
1da177e4 LT |
981 | Alexey Kuznetsov. |
982 | kuznet@ms2.inr.ac.ru | |
983 | ||
984 | Updated by: | |
985 | Andi Kleen | |
986 | ak@muc.de | |
987 | Nicolas Delon | |
988 | delon.nicolas@wanadoo.fr | |
989 | ||
990 | ||
991 | ||
992 | ||
993 | /proc/sys/net/ipv6/* Variables: | |
994 | ||
995 | IPv6 has no global variables such as tcp_*. tcp_* settings under ipv4/ also | |
996 | apply to IPv6 [XXX?]. | |
997 | ||
998 | bindv6only - BOOLEAN | |
999 | Default value for IPV6_V6ONLY socket option, | |
e18f5feb | 1000 | which restricts use of the IPv6 socket to IPv6 communication |
1da177e4 LT |
1001 | only. |
1002 | TRUE: disable IPv4-mapped address feature | |
1003 | FALSE: enable IPv4-mapped address feature | |
1004 | ||
1005 | Default: FALSE (as specified in RFC2553bis) | |
1006 | ||
1007 | IPv6 Fragmentation: | |
1008 | ||
1009 | ip6frag_high_thresh - INTEGER | |
e18f5feb | 1010 | Maximum memory used to reassemble IPv6 fragments. When |
1da177e4 LT |
1011 | ip6frag_high_thresh bytes of memory is allocated for this purpose, |
1012 | the fragment handler will toss packets until ip6frag_low_thresh | |
1013 | is reached. | |
e18f5feb | 1014 | |
1da177e4 | 1015 | ip6frag_low_thresh - INTEGER |
e18f5feb | 1016 | See ip6frag_high_thresh |
1da177e4 LT |
1017 | |
1018 | ip6frag_time - INTEGER | |
1019 | Time in seconds to keep an IPv6 fragment in memory. | |
1020 | ||
1021 | ip6frag_secret_interval - INTEGER | |
e18f5feb | 1022 | Regeneration interval (in seconds) of the hash secret (or lifetime |
1da177e4 LT |
1023 | for the hash secret) for IPv6 fragments. |
1024 | Default: 600 | |
1025 | ||
1026 | conf/default/*: | |
1027 | Change the interface-specific default settings. | |
1028 | ||
1029 | ||
1030 | conf/all/*: | |
e18f5feb | 1031 | Change all the interface-specific settings. |
1da177e4 LT |
1032 | |
1033 | [XXX: Other special features than forwarding?] | |
1034 | ||
1035 | conf/all/forwarding - BOOLEAN | |
e18f5feb | 1036 | Enable global IPv6 forwarding between all interfaces. |
1da177e4 | 1037 | |
e18f5feb | 1038 | IPv4 and IPv6 work differently here; e.g. netfilter must be used |
1da177e4 LT |
1039 | to control which interfaces may forward packets and which not. |
1040 | ||
e18f5feb | 1041 | This also sets all interfaces' Host/Router setting |
1da177e4 LT |
1042 | 'forwarding' to the specified value. See below for details. |
1043 | ||
1044 | This referred to as global forwarding. | |
1045 | ||
fbea49e1 YH |
1046 | proxy_ndp - BOOLEAN |
1047 | Do proxy ndp. | |
1048 | ||
1da177e4 LT |
1049 | conf/interface/*: |
1050 | Change special settings per interface. | |
1051 | ||
e18f5feb | 1052 | The functional behaviour for certain settings is different |
1da177e4 LT |
1053 | depending on whether local forwarding is enabled or not. |
1054 | ||
1055 | accept_ra - BOOLEAN | |
1056 | Accept Router Advertisements; autoconfigure using them. | |
e18f5feb | 1057 | |
ae8abfa0 TG |
1058 | Possible values are: |
1059 | 0 Do not accept Router Advertisements. | |
1060 | 1 Accept Router Advertisements if forwarding is disabled. | |
1061 | 2 Overrule forwarding behaviour. Accept Router Advertisements | |
1062 | even if forwarding is enabled. | |
1063 | ||
1da177e4 LT |
1064 | Functional default: enabled if local forwarding is disabled. |
1065 | disabled if local forwarding is enabled. | |
1066 | ||
65f5c7c1 YH |
1067 | accept_ra_defrtr - BOOLEAN |
1068 | Learn default router in Router Advertisement. | |
1069 | ||
1070 | Functional default: enabled if accept_ra is enabled. | |
1071 | disabled if accept_ra is disabled. | |
1072 | ||
c4fd30eb | 1073 | accept_ra_pinfo - BOOLEAN |
2fe0ae78 | 1074 | Learn Prefix Information in Router Advertisement. |
c4fd30eb YH |
1075 | |
1076 | Functional default: enabled if accept_ra is enabled. | |
1077 | disabled if accept_ra is disabled. | |
1078 | ||
09c884d4 YH |
1079 | accept_ra_rt_info_max_plen - INTEGER |
1080 | Maximum prefix length of Route Information in RA. | |
1081 | ||
1082 | Route Information w/ prefix larger than or equal to this | |
1083 | variable shall be ignored. | |
1084 | ||
1085 | Functional default: 0 if accept_ra_rtr_pref is enabled. | |
1086 | -1 if accept_ra_rtr_pref is disabled. | |
1087 | ||
930d6ff2 YH |
1088 | accept_ra_rtr_pref - BOOLEAN |
1089 | Accept Router Preference in RA. | |
1090 | ||
1091 | Functional default: enabled if accept_ra is enabled. | |
1092 | disabled if accept_ra is disabled. | |
1093 | ||
1da177e4 LT |
1094 | accept_redirects - BOOLEAN |
1095 | Accept Redirects. | |
1096 | ||
1097 | Functional default: enabled if local forwarding is disabled. | |
1098 | disabled if local forwarding is enabled. | |
1099 | ||
0bcbc926 YH |
1100 | accept_source_route - INTEGER |
1101 | Accept source routing (routing extension header). | |
1102 | ||
bb4dbf9e | 1103 | >= 0: Accept only routing header type 2. |
0bcbc926 YH |
1104 | < 0: Do not accept routing header. |
1105 | ||
1106 | Default: 0 | |
1107 | ||
1da177e4 | 1108 | autoconf - BOOLEAN |
e18f5feb | 1109 | Autoconfigure addresses using Prefix Information in Router |
1da177e4 LT |
1110 | Advertisements. |
1111 | ||
c4fd30eb YH |
1112 | Functional default: enabled if accept_ra_pinfo is enabled. |
1113 | disabled if accept_ra_pinfo is disabled. | |
1da177e4 LT |
1114 | |
1115 | dad_transmits - INTEGER | |
1116 | The amount of Duplicate Address Detection probes to send. | |
1117 | Default: 1 | |
e18f5feb | 1118 | |
1da177e4 | 1119 | forwarding - BOOLEAN |
e18f5feb | 1120 | Configure interface-specific Host/Router behaviour. |
1da177e4 | 1121 | |
e18f5feb | 1122 | Note: It is recommended to have the same setting on all |
1da177e4 LT |
1123 | interfaces; mixed router/host scenarios are rather uncommon. |
1124 | ||
ae8abfa0 TG |
1125 | Possible values are: |
1126 | 0 Forwarding disabled | |
1127 | 1 Forwarding enabled | |
1128 | 2 Forwarding enabled (Hybrid Mode) | |
1129 | ||
1130 | FALSE (0): | |
1da177e4 LT |
1131 | |
1132 | By default, Host behaviour is assumed. This means: | |
1133 | ||
1134 | 1. IsRouter flag is not set in Neighbour Advertisements. | |
1135 | 2. Router Solicitations are being sent when necessary. | |
e18f5feb | 1136 | 3. If accept_ra is TRUE (default), accept Router |
1da177e4 LT |
1137 | Advertisements (and do autoconfiguration). |
1138 | 4. If accept_redirects is TRUE (default), accept Redirects. | |
1139 | ||
ae8abfa0 | 1140 | TRUE (1): |
1da177e4 | 1141 | |
e18f5feb | 1142 | If local forwarding is enabled, Router behaviour is assumed. |
1da177e4 LT |
1143 | This means exactly the reverse from the above: |
1144 | ||
1145 | 1. IsRouter flag is set in Neighbour Advertisements. | |
1146 | 2. Router Solicitations are not sent. | |
ae8abfa0 | 1147 | 3. Router Advertisements are ignored unless accept_ra is 2. |
1da177e4 LT |
1148 | 4. Redirects are ignored. |
1149 | ||
ae8abfa0 TG |
1150 | TRUE (2): |
1151 | ||
1152 | Hybrid mode. Same behaviour as TRUE, except for: | |
1153 | ||
1154 | 2. Router Solicitations are being sent when necessary. | |
1155 | ||
1156 | Default: 0 (disabled) if global forwarding is disabled (default), | |
1157 | otherwise 1 (enabled). | |
1da177e4 LT |
1158 | |
1159 | hop_limit - INTEGER | |
1160 | Default Hop Limit to set. | |
1161 | Default: 64 | |
1162 | ||
1163 | mtu - INTEGER | |
1164 | Default Maximum Transfer Unit | |
1165 | Default: 1280 (IPv6 required minimum) | |
1166 | ||
52e16356 YH |
1167 | router_probe_interval - INTEGER |
1168 | Minimum interval (in seconds) between Router Probing described | |
1169 | in RFC4191. | |
1170 | ||
1171 | Default: 60 | |
1172 | ||
1da177e4 LT |
1173 | router_solicitation_delay - INTEGER |
1174 | Number of seconds to wait after interface is brought up | |
1175 | before sending Router Solicitations. | |
1176 | Default: 1 | |
1177 | ||
1178 | router_solicitation_interval - INTEGER | |
1179 | Number of seconds to wait between Router Solicitations. | |
1180 | Default: 4 | |
1181 | ||
1182 | router_solicitations - INTEGER | |
e18f5feb | 1183 | Number of Router Solicitations to send until assuming no |
1da177e4 LT |
1184 | routers are present. |
1185 | Default: 3 | |
1186 | ||
1187 | use_tempaddr - INTEGER | |
1188 | Preference for Privacy Extensions (RFC3041). | |
1189 | <= 0 : disable Privacy Extensions | |
1190 | == 1 : enable Privacy Extensions, but prefer public | |
1191 | addresses over temporary addresses. | |
1192 | > 1 : enable Privacy Extensions and prefer temporary | |
1193 | addresses over public addresses. | |
1194 | Default: 0 (for most devices) | |
1195 | -1 (for point-to-point devices and loopback devices) | |
1196 | ||
1197 | temp_valid_lft - INTEGER | |
1198 | valid lifetime (in seconds) for temporary addresses. | |
1199 | Default: 604800 (7 days) | |
1200 | ||
1201 | temp_prefered_lft - INTEGER | |
1202 | Preferred lifetime (in seconds) for temporary addresses. | |
1203 | Default: 86400 (1 day) | |
1204 | ||
1205 | max_desync_factor - INTEGER | |
1206 | Maximum value for DESYNC_FACTOR, which is a random value | |
e18f5feb | 1207 | that ensures that clients don't synchronize with each |
1da177e4 LT |
1208 | other and generate new addresses at exactly the same time. |
1209 | value is in seconds. | |
1210 | Default: 600 | |
e18f5feb | 1211 | |
1da177e4 LT |
1212 | regen_max_retry - INTEGER |
1213 | Number of attempts before give up attempting to generate | |
1214 | valid temporary addresses. | |
1215 | Default: 5 | |
1216 | ||
1217 | max_addresses - INTEGER | |
e79dc484 BH |
1218 | Maximum number of autoconfigured addresses per interface. Setting |
1219 | to zero disables the limitation. It is not recommended to set this | |
1220 | value too large (or to zero) because it would be an easy way to | |
1221 | crash the kernel by allowing too many addresses to be created. | |
1da177e4 LT |
1222 | Default: 16 |
1223 | ||
778d80be | 1224 | disable_ipv6 - BOOLEAN |
9bdd8d40 BH |
1225 | Disable IPv6 operation. If accept_dad is set to 2, this value |
1226 | will be dynamically set to TRUE if DAD fails for the link-local | |
1227 | address. | |
778d80be YH |
1228 | Default: FALSE (enable IPv6 operation) |
1229 | ||
56d417b1 BH |
1230 | When this value is changed from 1 to 0 (IPv6 is being enabled), |
1231 | it will dynamically create a link-local address on the given | |
1232 | interface and start Duplicate Address Detection, if necessary. | |
1233 | ||
1234 | When this value is changed from 0 to 1 (IPv6 is being disabled), | |
1235 | it will dynamically delete all address on the given interface. | |
1236 | ||
1b34be74 YH |
1237 | accept_dad - INTEGER |
1238 | Whether to accept DAD (Duplicate Address Detection). | |
1239 | 0: Disable DAD | |
1240 | 1: Enable DAD (default) | |
1241 | 2: Enable DAD, and disable IPv6 operation if MAC-based duplicate | |
1242 | link-local address has been found. | |
1243 | ||
f7734fdf OP |
1244 | force_tllao - BOOLEAN |
1245 | Enable sending the target link-layer address option even when | |
1246 | responding to a unicast neighbor solicitation. | |
1247 | Default: FALSE | |
1248 | ||
1249 | Quoting from RFC 2461, section 4.4, Target link-layer address: | |
1250 | ||
1251 | "The option MUST be included for multicast solicitations in order to | |
1252 | avoid infinite Neighbor Solicitation "recursion" when the peer node | |
1253 | does not have a cache entry to return a Neighbor Advertisements | |
1254 | message. When responding to unicast solicitations, the option can be | |
1255 | omitted since the sender of the solicitation has the correct link- | |
1256 | layer address; otherwise it would not have be able to send the unicast | |
1257 | solicitation in the first place. However, including the link-layer | |
1258 | address in this case adds little overhead and eliminates a potential | |
1259 | race condition where the sender deletes the cached link-layer address | |
1260 | prior to receiving a response to a previous solicitation." | |
1261 | ||
1da177e4 LT |
1262 | icmp/*: |
1263 | ratelimit - INTEGER | |
1264 | Limit the maximal rates for sending ICMPv6 packets. | |
6dbf4bca SH |
1265 | 0 to disable any limiting, |
1266 | otherwise the minimal space between responses in milliseconds. | |
1267 | Default: 1000 | |
1da177e4 LT |
1268 | |
1269 | ||
1270 | IPv6 Update by: | |
1271 | Pekka Savola <pekkas@netcore.fi> | |
1272 | YOSHIFUJI Hideaki / USAGI Project <yoshfuji@linux-ipv6.org> | |
1273 | ||
1274 | ||
1275 | /proc/sys/net/bridge/* Variables: | |
1276 | ||
1277 | bridge-nf-call-arptables - BOOLEAN | |
1278 | 1 : pass bridged ARP traffic to arptables' FORWARD chain. | |
1279 | 0 : disable this. | |
1280 | Default: 1 | |
1281 | ||
1282 | bridge-nf-call-iptables - BOOLEAN | |
1283 | 1 : pass bridged IPv4 traffic to iptables' chains. | |
1284 | 0 : disable this. | |
1285 | Default: 1 | |
1286 | ||
1287 | bridge-nf-call-ip6tables - BOOLEAN | |
1288 | 1 : pass bridged IPv6 traffic to ip6tables' chains. | |
1289 | 0 : disable this. | |
1290 | Default: 1 | |
1291 | ||
1292 | bridge-nf-filter-vlan-tagged - BOOLEAN | |
516299d2 MM |
1293 | 1 : pass bridged vlan-tagged ARP/IP/IPv6 traffic to {arp,ip,ip6}tables. |
1294 | 0 : disable this. | |
1295 | Default: 1 | |
1296 | ||
1297 | bridge-nf-filter-pppoe-tagged - BOOLEAN | |
1298 | 1 : pass bridged pppoe-tagged IP/IPv6 traffic to {ip,ip6}tables. | |
1da177e4 LT |
1299 | 0 : disable this. |
1300 | Default: 1 | |
1301 | ||
1302 | ||
32e8d494 VY |
1303 | proc/sys/net/sctp/* Variables: |
1304 | ||
1305 | addip_enable - BOOLEAN | |
1306 | Enable or disable extension of Dynamic Address Reconfiguration | |
1307 | (ADD-IP) functionality specified in RFC5061. This extension provides | |
1308 | the ability to dynamically add and remove new addresses for the SCTP | |
1309 | associations. | |
1310 | ||
1311 | 1: Enable extension. | |
1312 | ||
1313 | 0: Disable extension. | |
1314 | ||
1315 | Default: 0 | |
1316 | ||
1317 | addip_noauth_enable - BOOLEAN | |
1318 | Dynamic Address Reconfiguration (ADD-IP) requires the use of | |
1319 | authentication to protect the operations of adding or removing new | |
1320 | addresses. This requirement is mandated so that unauthorized hosts | |
1321 | would not be able to hijack associations. However, older | |
1322 | implementations may not have implemented this requirement while | |
1323 | allowing the ADD-IP extension. For reasons of interoperability, | |
1324 | we provide this variable to control the enforcement of the | |
1325 | authentication requirement. | |
1326 | ||
1327 | 1: Allow ADD-IP extension to be used without authentication. This | |
1328 | should only be set in a closed environment for interoperability | |
1329 | with older implementations. | |
1330 | ||
1331 | 0: Enforce the authentication requirement | |
1332 | ||
1333 | Default: 0 | |
1334 | ||
1335 | auth_enable - BOOLEAN | |
1336 | Enable or disable Authenticated Chunks extension. This extension | |
1337 | provides the ability to send and receive authenticated chunks and is | |
1338 | required for secure operation of Dynamic Address Reconfiguration | |
1339 | (ADD-IP) extension. | |
1340 | ||
1341 | 1: Enable this extension. | |
1342 | 0: Disable this extension. | |
1343 | ||
1344 | Default: 0 | |
1345 | ||
1346 | prsctp_enable - BOOLEAN | |
1347 | Enable or disable the Partial Reliability extension (RFC3758) which | |
1348 | is used to notify peers that a given DATA should no longer be expected. | |
1349 | ||
1350 | 1: Enable extension | |
1351 | 0: Disable | |
1352 | ||
1353 | Default: 1 | |
1354 | ||
1355 | max_burst - INTEGER | |
1356 | The limit of the number of new packets that can be initially sent. It | |
1357 | controls how bursty the generated traffic can be. | |
1358 | ||
1359 | Default: 4 | |
1360 | ||
1361 | association_max_retrans - INTEGER | |
1362 | Set the maximum number for retransmissions that an association can | |
1363 | attempt deciding that the remote end is unreachable. If this value | |
1364 | is exceeded, the association is terminated. | |
1365 | ||
1366 | Default: 10 | |
1367 | ||
1368 | max_init_retransmits - INTEGER | |
1369 | The maximum number of retransmissions of INIT and COOKIE-ECHO chunks | |
1370 | that an association will attempt before declaring the destination | |
1371 | unreachable and terminating. | |
1372 | ||
1373 | Default: 8 | |
1374 | ||
1375 | path_max_retrans - INTEGER | |
1376 | The maximum number of retransmissions that will be attempted on a given | |
1377 | path. Once this threshold is exceeded, the path is considered | |
1378 | unreachable, and new traffic will use a different path when the | |
1379 | association is multihomed. | |
1380 | ||
1381 | Default: 5 | |
1382 | ||
1383 | rto_initial - INTEGER | |
1384 | The initial round trip timeout value in milliseconds that will be used | |
1385 | in calculating round trip times. This is the initial time interval | |
1386 | for retransmissions. | |
1387 | ||
1388 | Default: 3000 | |
1da177e4 | 1389 | |
32e8d494 VY |
1390 | rto_max - INTEGER |
1391 | The maximum value (in milliseconds) of the round trip timeout. This | |
1392 | is the largest time interval that can elapse between retransmissions. | |
1393 | ||
1394 | Default: 60000 | |
1395 | ||
1396 | rto_min - INTEGER | |
1397 | The minimum value (in milliseconds) of the round trip timeout. This | |
1398 | is the smallest time interval the can elapse between retransmissions. | |
1399 | ||
1400 | Default: 1000 | |
1401 | ||
1402 | hb_interval - INTEGER | |
1403 | The interval (in milliseconds) between HEARTBEAT chunks. These chunks | |
1404 | are sent at the specified interval on idle paths to probe the state of | |
1405 | a given path between 2 associations. | |
1406 | ||
1407 | Default: 30000 | |
1408 | ||
1409 | sack_timeout - INTEGER | |
1410 | The amount of time (in milliseconds) that the implementation will wait | |
1411 | to send a SACK. | |
1412 | ||
1413 | Default: 200 | |
1414 | ||
1415 | valid_cookie_life - INTEGER | |
1416 | The default lifetime of the SCTP cookie (in milliseconds). The cookie | |
1417 | is used during association establishment. | |
1418 | ||
1419 | Default: 60000 | |
1420 | ||
1421 | cookie_preserve_enable - BOOLEAN | |
1422 | Enable or disable the ability to extend the lifetime of the SCTP cookie | |
1423 | that is used during the establishment phase of SCTP association | |
1424 | ||
1425 | 1: Enable cookie lifetime extension. | |
1426 | 0: Disable | |
1427 | ||
1428 | Default: 1 | |
1429 | ||
1430 | rcvbuf_policy - INTEGER | |
1431 | Determines if the receive buffer is attributed to the socket or to | |
1432 | association. SCTP supports the capability to create multiple | |
1433 | associations on a single socket. When using this capability, it is | |
1434 | possible that a single stalled association that's buffering a lot | |
1435 | of data may block other associations from delivering their data by | |
1436 | consuming all of the receive buffer space. To work around this, | |
1437 | the rcvbuf_policy could be set to attribute the receiver buffer space | |
1438 | to each association instead of the socket. This prevents the described | |
1439 | blocking. | |
1440 | ||
1441 | 1: rcvbuf space is per association | |
1442 | 0: recbuf space is per socket | |
1443 | ||
1444 | Default: 0 | |
1445 | ||
1446 | sndbuf_policy - INTEGER | |
1447 | Similar to rcvbuf_policy above, this applies to send buffer space. | |
1448 | ||
1449 | 1: Send buffer is tracked per association | |
1450 | 0: Send buffer is tracked per socket. | |
1451 | ||
1452 | Default: 0 | |
1453 | ||
1454 | sctp_mem - vector of 3 INTEGERs: min, pressure, max | |
1455 | Number of pages allowed for queueing by all SCTP sockets. | |
1456 | ||
1457 | min: Below this number of pages SCTP is not bothered about its | |
1458 | memory appetite. When amount of memory allocated by SCTP exceeds | |
1459 | this number, SCTP starts to moderate memory usage. | |
1460 | ||
1461 | pressure: This value was introduced to follow format of tcp_mem. | |
1462 | ||
1463 | max: Number of pages allowed for queueing by all SCTP sockets. | |
1464 | ||
1465 | Default is calculated at boot time from amount of available memory. | |
1466 | ||
1467 | sctp_rmem - vector of 3 INTEGERs: min, default, max | |
1468 | See tcp_rmem for a description. | |
1469 | ||
1470 | sctp_wmem - vector of 3 INTEGERs: min, default, max | |
1471 | See tcp_wmem for a description. | |
1472 | ||
72388433 BD |
1473 | addr_scope_policy - INTEGER |
1474 | Control IPv4 address scoping - draft-stewart-tsvwg-sctp-ipv4-00 | |
1475 | ||
1476 | 0 - Disable IPv4 address scoping | |
1477 | 1 - Enable IPv4 address scoping | |
1478 | 2 - Follow draft but allow IPv4 private addresses | |
1479 | 3 - Follow draft but allow IPv4 link local addresses | |
1480 | ||
1481 | Default: 1 | |
1482 | ||
1da177e4 | 1483 | |
4edc2f34 | 1484 | /proc/sys/net/core/* |
705efc3b WT |
1485 | dev_weight - INTEGER |
1486 | The maximum number of packets that kernel can handle on a NAPI | |
1487 | interrupt, it's a Per-CPU variable. | |
1488 | ||
1489 | Default: 64 | |
4edc2f34 SH |
1490 | |
1491 | /proc/sys/net/unix/* | |
705efc3b WT |
1492 | max_dgram_qlen - INTEGER |
1493 | The maximum length of dgram socket receive queue | |
1494 | ||
1495 | Default: 10 | |
1496 | ||
1497 | ||
1498 | UNDOCUMENTED: | |
4edc2f34 SH |
1499 | |
1500 | /proc/sys/net/irda/* | |
1501 | fast_poll_increase FIXME | |
1502 | warn_noreply_time FIXME | |
1503 | discovery_slots FIXME | |
1504 | slot_timeout FIXME | |
1505 | max_baud_rate FIXME | |
1506 | discovery_timeout FIXME | |
1507 | lap_keepalive_time FIXME | |
1508 | max_noreply_time FIXME | |
1509 | max_tx_data_size FIXME | |
1510 | max_tx_window FIXME | |
1511 | min_tx_turn_time FIXME |