| blob | e40f75322377a84049cccec186cf4f07a01f7211 |
1 #
2 # IP configuration
3 #
4 config IP_MULTICAST
5 bool "IP: multicasting"
6 help
7 This is code for addressing several networked computers at once,
8 enlarging your kernel by about 2 KB. You need multicasting if you
9 intend to participate in the MBONE, a high bandwidth network on top
10 of the Internet which carries audio and video broadcasts. More
11 information about the MBONE is on the WWW at
12 <http://www-itg.lbl.gov/mbone/>. Information about the multicast
13 capabilities of the various network cards is contained in
14 <file:Documentation/networking/multicast.txt>. For most people, it's
15 safe to say N.
17 config IP_ADVANCED_ROUTER
18 bool "IP: advanced router"
19 ---help---
20 If you intend to run your Linux box mostly as a router, i.e. as a
21 computer that forwards and redistributes network packets, say Y; you
22 will then be presented with several options that allow more precise
23 control about the routing process.
25 The answer to this question won't directly affect the kernel:
26 answering N will just cause the configurator to skip all the
27 questions about advanced routing.
29 Note that your box can only act as a router if you enable IP
30 forwarding in your kernel; you can do that by saying Y to "/proc
31 file system support" and "Sysctl support" below and executing the
32 line
34 echo "1" > /proc/sys/net/ipv4/ip_forward
36 at boot time after the /proc file system has been mounted.
38 If you turn on IP forwarding, you will also get the rp_filter, which
39 automatically rejects incoming packets if the routing table entry
40 for their source address doesn't match the network interface they're
41 arriving on. This has security advantages because it prevents the
42 so-called IP spoofing, however it can pose problems if you use
43 asymmetric routing (packets from you to a host take a different path
44 than packets from that host to you) or if you operate a non-routing
45 host which has several IP addresses on different interfaces. To turn
46 rp_filter off use:
48 echo 0 > /proc/sys/net/ipv4/conf/<device>/rp_filter
49 or
50 echo 0 > /proc/sys/net/ipv4/conf/all/rp_filter
52 If unsure, say N here.
54 choice
55 prompt "Choose IP: FIB lookup algorithm (choose FIB_HASH if unsure)"
56 depends on IP_ADVANCED_ROUTER
57 default ASK_IP_FIB_HASH
59 config ASK_IP_FIB_HASH
60 bool "FIB_HASH"
61 ---help---
62 Current FIB is very proven and good enough for most users.
64 config IP_FIB_TRIE
65 bool "FIB_TRIE"
66 ---help---
67 Use new experimental LC-trie as FIB lookup algoritm.
68 This improves lookup performance if you have a large
69 number of routes.
71 LC-trie is a longest matching prefix lookup algorithm which
72 performs better than FIB_HASH for large routing tables.
73 But, it consumes more memory and is more complex.
75 LC-trie is described in:
77 IP-address lookup using LC-tries. Stefan Nilsson and Gunnar Karlsson
78 IEEE Journal on Selected Areas in Communications, 17(6):1083-1092, June 1999
79 An experimental study of compression methods for dynamic tries
80 Stefan Nilsson and Matti Tikkanen. Algorithmica, 33(1):19-33, 2002.
81 http://www.nada.kth.se/~snilsson/public/papers/dyntrie2/
83 endchoice
85 config IP_FIB_HASH
86 def_bool ASK_IP_FIB_HASH || !IP_ADVANCED_ROUTER
88 config IP_MULTIPLE_TABLES
89 bool "IP: policy routing"
90 depends on IP_ADVANCED_ROUTER
91 ---help---
92 Normally, a router decides what to do with a received packet based
93 solely on the packet's final destination address. If you say Y here,
94 the Linux router will also be able to take the packet's source
95 address into account. Furthermore, the TOS (Type-Of-Service) field
96 of the packet can be used for routing decisions as well.
98 If you are interested in this, please see the preliminary
99 documentation at <http://www.compendium.com.ar/policy-routing.txt>
100 and <ftp://post.tepkom.ru/pub/vol2/Linux/docs/advanced-routing.tex>.
101 You will need supporting software from
102 <ftp://ftp.tux.org/pub/net/ip-routing/>.
104 If unsure, say N.
106 config IP_ROUTE_FWMARK
107 bool "IP: use netfilter MARK value as routing key"
108 depends on IP_MULTIPLE_TABLES && NETFILTER
109 help
110 If you say Y here, you will be able to specify different routes for
111 packets with different mark values (see iptables(8), MARK target).
113 config IP_ROUTE_MULTIPATH
114 bool "IP: equal cost multipath"
115 depends on IP_ADVANCED_ROUTER
116 help
117 Normally, the routing tables specify a single action to be taken in
118 a deterministic manner for a given packet. If you say Y here
119 however, it becomes possible to attach several actions to a packet
120 pattern, in effect specifying several alternative paths to travel
121 for those packets. The router considers all these paths to be of
122 equal "cost" and chooses one of them in a non-deterministic fashion
123 if a matching packet arrives.
125 config IP_ROUTE_MULTIPATH_CACHED
126 bool "IP: equal cost multipath with caching support (EXPERIMENTAL)"
127 depends on IP_ROUTE_MULTIPATH
128 help
129 Normally, equal cost multipath routing is not supported by the
130 routing cache. If you say Y here, alternative routes are cached
131 and on cache lookup a route is chosen in a configurable fashion.
133 If unsure, say N.
135 config IP_ROUTE_MULTIPATH_RR
136 tristate "MULTIPATH: round robin algorithm"
137 depends on IP_ROUTE_MULTIPATH_CACHED
138 help
139 Mulitpath routes are chosen according to Round Robin
141 config IP_ROUTE_MULTIPATH_RANDOM
142 tristate "MULTIPATH: random algorithm"
143 depends on IP_ROUTE_MULTIPATH_CACHED
144 help
145 Multipath routes are chosen in a random fashion. Actually,
146 there is no weight for a route. The advantage of this policy
147 is that it is implemented stateless and therefore introduces only
148 a very small delay.
150 config IP_ROUTE_MULTIPATH_WRANDOM
151 tristate "MULTIPATH: weighted random algorithm"
152 depends on IP_ROUTE_MULTIPATH_CACHED
153 help
154 Multipath routes are chosen in a weighted random fashion.
155 The per route weights are the weights visible via ip route 2. As the
156 corresponding state management introduces some overhead routing delay
157 is increased.
159 config IP_ROUTE_MULTIPATH_DRR
160 tristate "MULTIPATH: interface round robin algorithm"
161 depends on IP_ROUTE_MULTIPATH_CACHED
162 help
163 Connections are distributed in a round robin fashion over the
164 available interfaces. This policy makes sense if the connections
165 should be primarily distributed on interfaces and not on routes.
167 config IP_ROUTE_VERBOSE
168 bool "IP: verbose route monitoring"
169 depends on IP_ADVANCED_ROUTER
170 help
171 If you say Y here, which is recommended, then the kernel will print
172 verbose messages regarding the routing, for example warnings about
173 received packets which look strange and could be evidence of an
174 attack or a misconfigured system somewhere. The information is
175 handled by the klogd daemon which is responsible for kernel messages
176 ("man klogd").
178 config IP_PNP
179 bool "IP: kernel level autoconfiguration"
180 help
181 This enables automatic configuration of IP addresses of devices and
182 of the routing table during kernel boot, based on either information
183 supplied on the kernel command line or by BOOTP or RARP protocols.
184 You need to say Y only for diskless machines requiring network
185 access to boot (in which case you want to say Y to "Root file system
186 on NFS" as well), because all other machines configure the network
187 in their startup scripts.
189 config IP_PNP_DHCP
190 bool "IP: DHCP support"
191 depends on IP_PNP
192 ---help---
193 If you want your Linux box to mount its whole root file system (the
194 one containing the directory /) from some other computer over the
195 net via NFS and you want the IP address of your computer to be
196 discovered automatically at boot time using the DHCP protocol (a
197 special protocol designed for doing this job), say Y here. In case
198 the boot ROM of your network card was designed for booting Linux and
199 does DHCP itself, providing all necessary information on the kernel
200 command line, you can say N here.
202 If unsure, say Y. Note that if you want to use DHCP, a DHCP server
203 must be operating on your network. Read
204 <file:Documentation/nfsroot.txt> for details.
206 config IP_PNP_BOOTP
207 bool "IP: BOOTP support"
208 depends on IP_PNP
209 ---help---
210 If you want your Linux box to mount its whole root file system (the
211 one containing the directory /) from some other computer over the
212 net via NFS and you want the IP address of your computer to be
213 discovered automatically at boot time using the BOOTP protocol (a
214 special protocol designed for doing this job), say Y here. In case
215 the boot ROM of your network card was designed for booting Linux and
216 does BOOTP itself, providing all necessary information on the kernel
217 command line, you can say N here. If unsure, say Y. Note that if you
218 want to use BOOTP, a BOOTP server must be operating on your network.
219 Read <file:Documentation/nfsroot.txt> for details.
221 config IP_PNP_RARP
222 bool "IP: RARP support"
223 depends on IP_PNP
224 help
225 If you want your Linux box to mount its whole root file system (the
226 one containing the directory /) from some other computer over the
227 net via NFS and you want the IP address of your computer to be
228 discovered automatically at boot time using the RARP protocol (an
229 older protocol which is being obsoleted by BOOTP and DHCP), say Y
230 here. Note that if you want to use RARP, a RARP server must be
231 operating on your network. Read <file:Documentation/nfsroot.txt> for
232 details.
234 # not yet ready..
235 # bool ' IP: ARP support' CONFIG_IP_PNP_ARP
236 config NET_IPIP
237 tristate "IP: tunneling"
238 select INET_TUNNEL
239 ---help---
240 Tunneling means encapsulating data of one protocol type within
241 another protocol and sending it over a channel that understands the
242 encapsulating protocol. This particular tunneling driver implements
243 encapsulation of IP within IP, which sounds kind of pointless, but
244 can be useful if you want to make your (or some other) machine
245 appear on a different network than it physically is, or to use
246 mobile-IP facilities (allowing laptops to seamlessly move between
247 networks without changing their IP addresses).
249 Saying Y to this option will produce two modules ( = code which can
250 be inserted in and removed from the running kernel whenever you
251 want). Most people won't need this and can say N.
253 config NET_IPGRE
254 tristate "IP: GRE tunnels over IP"
255 help
256 Tunneling means encapsulating data of one protocol type within
257 another protocol and sending it over a channel that understands the
258 encapsulating protocol. This particular tunneling driver implements
259 GRE (Generic Routing Encapsulation) and at this time allows
260 encapsulating of IPv4 or IPv6 over existing IPv4 infrastructure.
261 This driver is useful if the other endpoint is a Cisco router: Cisco
262 likes GRE much better than the other Linux tunneling driver ("IP
263 tunneling" above). In addition, GRE allows multicast redistribution
264 through the tunnel.
266 config NET_IPGRE_BROADCAST
267 bool "IP: broadcast GRE over IP"
268 depends on IP_MULTICAST && NET_IPGRE
269 help
270 One application of GRE/IP is to construct a broadcast WAN (Wide Area
271 Network), which looks like a normal Ethernet LAN (Local Area
272 Network), but can be distributed all over the Internet. If you want
273 to do that, say Y here and to "IP multicast routing" below.
275 config IP_MROUTE
276 bool "IP: multicast routing"
277 depends on IP_MULTICAST
278 help
279 This is used if you want your machine to act as a router for IP
280 packets that have several destination addresses. It is needed on the
281 MBONE, a high bandwidth network on top of the Internet which carries
282 audio and video broadcasts. In order to do that, you would most
283 likely run the program mrouted. Information about the multicast
284 capabilities of the various network cards is contained in
285 <file:Documentation/networking/multicast.txt>. If you haven't heard
286 about it, you don't need it.
288 config IP_PIMSM_V1
289 bool "IP: PIM-SM version 1 support"
290 depends on IP_MROUTE
291 help
292 Kernel side support for Sparse Mode PIM (Protocol Independent
293 Multicast) version 1. This multicast routing protocol is used widely
294 because Cisco supports it. You need special software to use it
295 (pimd-v1). Please see <http://netweb.usc.edu/pim/> for more
296 information about PIM.
298 Say Y if you want to use PIM-SM v1. Note that you can say N here if
299 you just want to use Dense Mode PIM.
301 config IP_PIMSM_V2
302 bool "IP: PIM-SM version 2 support"
303 depends on IP_MROUTE
304 help
305 Kernel side support for Sparse Mode PIM version 2. In order to use
306 this, you need an experimental routing daemon supporting it (pimd or
307 gated-5). This routing protocol is not used widely, so say N unless
308 you want to play with it.
310 config ARPD
311 bool "IP: ARP daemon support (EXPERIMENTAL)"
312 depends on EXPERIMENTAL
313 ---help---
314 Normally, the kernel maintains an internal cache which maps IP
315 addresses to hardware addresses on the local network, so that
316 Ethernet/Token Ring/ etc. frames are sent to the proper address on
317 the physical networking layer. For small networks having a few
318 hundred directly connected hosts or less, keeping this address
319 resolution (ARP) cache inside the kernel works well. However,
320 maintaining an internal ARP cache does not work well for very large
321 switched networks, and will use a lot of kernel memory if TCP/IP
322 connections are made to many machines on the network.
324 If you say Y here, the kernel's internal ARP cache will never grow
325 to more than 256 entries (the oldest entries are expired in a LIFO
326 manner) and communication will be attempted with the user space ARP
327 daemon arpd. Arpd then answers the address resolution request either
328 from its own cache or by asking the net.
330 This code is experimental and also obsolete. If you want to use it,
331 you need to find a version of the daemon arpd on the net somewhere,
332 and you should also say Y to "Kernel/User network link driver",
333 below. If unsure, say N.
335 config SYN_COOKIES
336 bool "IP: TCP syncookie support (disabled per default)"
337 ---help---
338 Normal TCP/IP networking is open to an attack known as "SYN
339 flooding". This denial-of-service attack prevents legitimate remote
340 users from being able to connect to your computer during an ongoing
341 attack and requires very little work from the attacker, who can
342 operate from anywhere on the Internet.
344 SYN cookies provide protection against this type of attack. If you
345 say Y here, the TCP/IP stack will use a cryptographic challenge
346 protocol known as "SYN cookies" to enable legitimate users to
347 continue to connect, even when your machine is under attack. There
348 is no need for the legitimate users to change their TCP/IP software;
349 SYN cookies work transparently to them. For technical information
350 about SYN cookies, check out <http://cr.yp.to/syncookies.html>.
352 If you are SYN flooded, the source address reported by the kernel is
353 likely to have been forged by the attacker; it is only reported as
354 an aid in tracing the packets to their actual source and should not
355 be taken as absolute truth.
357 SYN cookies may prevent correct error reporting on clients when the
358 server is really overloaded. If this happens frequently better turn
359 them off.
361 If you say Y here, note that SYN cookies aren't enabled by default;
362 you can enable them by saying Y to "/proc file system support" and
363 "Sysctl support" below and executing the command
365 echo 1 >/proc/sys/net/ipv4/tcp_syncookies
367 at boot time after the /proc file system has been mounted.
369 If unsure, say N.
371 config INET_AH
372 tristate "IP: AH transformation"
373 select XFRM
374 select CRYPTO
375 select CRYPTO_HMAC
376 select CRYPTO_MD5
377 select CRYPTO_SHA1
378 ---help---
379 Support for IPsec AH.
381 If unsure, say Y.
383 config INET_ESP
384 tristate "IP: ESP transformation"
385 select XFRM
386 select CRYPTO
387 select CRYPTO_HMAC
388 select CRYPTO_MD5
389 select CRYPTO_SHA1
390 select CRYPTO_DES
391 ---help---
392 Support for IPsec ESP.
394 If unsure, say Y.
396 config INET_IPCOMP
397 tristate "IP: IPComp transformation"
398 select XFRM
399 select INET_XFRM_TUNNEL
400 select CRYPTO
401 select CRYPTO_DEFLATE
402 ---help---
403 Support for IP Payload Compression Protocol (IPComp) (RFC3173),
404 typically needed for IPsec.
406 If unsure, say Y.
408 config INET_XFRM_TUNNEL
409 tristate
410 select INET_TUNNEL
411 default n
413 config INET_TUNNEL
414 tristate
415 default n
417 config INET_DIAG
418 tristate "INET: socket monitoring interface"
419 default y
420 ---help---
421 Support for INET (TCP, DCCP, etc) socket monitoring interface used by
422 native Linux tools such as ss. ss is included in iproute2, currently
423 downloadable at <http://developer.osdl.org/dev/iproute2>.
425 If unsure, say Y.
427 config INET_TCP_DIAG
428 depends on INET_DIAG
429 def_tristate INET_DIAG
431 config TCP_CONG_ADVANCED
432 bool "TCP: advanced congestion control"
433 ---help---
434 Support for selection of various TCP congestion control
435 modules.
437 Nearly all users can safely say no here, and a safe default
438 selection will be made (BIC-TCP with new Reno as a fallback).
440 If unsure, say N.
442 # TCP Reno is builtin (required as fallback)
443 menu "TCP congestion control"
444 depends on TCP_CONG_ADVANCED
446 config TCP_CONG_BIC
447 tristate "Binary Increase Congestion (BIC) control"
448 default y
449 ---help---
450 BIC-TCP is a sender-side only change that ensures a linear RTT
451 fairness under large windows while offering both scalability and
452 bounded TCP-friendliness. The protocol combines two schemes
453 called additive increase and binary search increase. When the
454 congestion window is large, additive increase with a large
455 increment ensures linear RTT fairness as well as good
456 scalability. Under small congestion windows, binary search
457 increase provides TCP friendliness.
458 See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/
460 config TCP_CONG_CUBIC
461 tristate "CUBIC TCP"
462 default m
463 ---help---
464 This is version 2.0 of BIC-TCP which uses a cubic growth function
465 among other techniques.
466 See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/cubic-paper.pdf
468 config TCP_CONG_WESTWOOD
469 tristate "TCP Westwood+"
470 default m
471 ---help---
472 TCP Westwood+ is a sender-side only modification of the TCP Reno
473 protocol stack that optimizes the performance of TCP congestion
474 control. It is based on end-to-end bandwidth estimation to set
475 congestion window and slow start threshold after a congestion
476 episode. Using this estimation, TCP Westwood+ adaptively sets a
477 slow start threshold and a congestion window which takes into
478 account the bandwidth used at the time congestion is experienced.
479 TCP Westwood+ significantly increases fairness wrt TCP Reno in
480 wired networks and throughput over wireless links.
482 config TCP_CONG_HTCP
483 tristate "H-TCP"
484 default m
485 ---help---
486 H-TCP is a send-side only modifications of the TCP Reno
487 protocol stack that optimizes the performance of TCP
488 congestion control for high speed network links. It uses a
489 modeswitch to change the alpha and beta parameters of TCP Reno
490 based on network conditions and in a way so as to be fair with
491 other Reno and H-TCP flows.
493 config TCP_CONG_HSTCP
494 tristate "High Speed TCP"
495 depends on EXPERIMENTAL
496 default n
497 ---help---
498 Sally Floyd's High Speed TCP (RFC 3649) congestion control.
499 A modification to TCP's congestion control mechanism for use
500 with large congestion windows. A table indicates how much to
501 increase the congestion window by when an ACK is received.
502 For more detail see http://www.icir.org/floyd/hstcp.html
504 config TCP_CONG_HYBLA
505 tristate "TCP-Hybla congestion control algorithm"
506 depends on EXPERIMENTAL
507 default n
508 ---help---
509 TCP-Hybla is a sender-side only change that eliminates penalization of
510 long-RTT, large-bandwidth connections, like when satellite legs are
511 involved, expecially when sharing a common bottleneck with normal
512 terrestrial connections.
514 config TCP_CONG_VEGAS
515 tristate "TCP Vegas"
516 depends on EXPERIMENTAL
517 default n
518 ---help---
519 TCP Vegas is a sender-side only change to TCP that anticipates
520 the onset of congestion by estimating the bandwidth. TCP Vegas
521 adjusts the sending rate by modifying the congestion
522 window. TCP Vegas should provide less packet loss, but it is
523 not as aggressive as TCP Reno.
525 config TCP_CONG_SCALABLE
526 tristate "Scalable TCP"
527 depends on EXPERIMENTAL
528 default n
529 ---help---
530 Scalable TCP is a sender-side only change to TCP which uses a
531 MIMD congestion control algorithm which has some nice scaling
532 properties, though is known to have fairness issues.
533 See http://www-lce.eng.cam.ac.uk/~ctk21/scalable/
535 endmenu
537 config TCP_CONG_BIC
538 tristate
539 depends on !TCP_CONG_ADVANCED
540 default y
542 source "net/ipv4/ipvs/Kconfig"