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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.savetz.com/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 on use:
48 echo 1 > /proc/sys/net/ipv4/conf/<device>/rp_filter
49 or
50 echo 1 > /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 algorithm.
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 select FIB_RULES
92 ---help---
93 Normally, a router decides what to do with a received packet based
94 solely on the packet's final destination address. If you say Y here,
95 the Linux router will also be able to take the packet's source
96 address into account. Furthermore, the TOS (Type-Of-Service) field
97 of the packet can be used for routing decisions as well.
99 If you are interested in this, please see the preliminary
100 documentation at <http://www.compendium.com.ar/policy-routing.txt>
101 and <ftp://post.tepkom.ru/pub/vol2/Linux/docs/advanced-routing.tex>.
102 You will need supporting software from
103 <ftp://ftp.tux.org/pub/net/ip-routing/>.
105 If unsure, say N.
107 config IP_ROUTE_MULTIPATH
108 bool "IP: equal cost multipath"
109 depends on IP_ADVANCED_ROUTER
110 help
111 Normally, the routing tables specify a single action to be taken in
112 a deterministic manner for a given packet. If you say Y here
113 however, it becomes possible to attach several actions to a packet
114 pattern, in effect specifying several alternative paths to travel
115 for those packets. The router considers all these paths to be of
116 equal "cost" and chooses one of them in a non-deterministic fashion
117 if a matching packet arrives.
119 config IP_ROUTE_VERBOSE
120 bool "IP: verbose route monitoring"
121 depends on IP_ADVANCED_ROUTER
122 help
123 If you say Y here, which is recommended, then the kernel will print
124 verbose messages regarding the routing, for example warnings about
125 received packets which look strange and could be evidence of an
126 attack or a misconfigured system somewhere. The information is
127 handled by the klogd daemon which is responsible for kernel messages
128 ("man klogd").
130 config IP_PNP
131 bool "IP: kernel level autoconfiguration"
132 help
133 This enables automatic configuration of IP addresses of devices and
134 of the routing table during kernel boot, based on either information
135 supplied on the kernel command line or by BOOTP or RARP protocols.
136 You need to say Y only for diskless machines requiring network
137 access to boot (in which case you want to say Y to "Root file system
138 on NFS" as well), because all other machines configure the network
139 in their startup scripts.
141 config IP_PNP_DHCP
142 bool "IP: DHCP support"
143 depends on IP_PNP
144 ---help---
145 If you want your Linux box to mount its whole root file system (the
146 one containing the directory /) from some other computer over the
147 net via NFS and you want the IP address of your computer to be
148 discovered automatically at boot time using the DHCP protocol (a
149 special protocol designed for doing this job), say Y here. In case
150 the boot ROM of your network card was designed for booting Linux and
151 does DHCP itself, providing all necessary information on the kernel
152 command line, you can say N here.
154 If unsure, say Y. Note that if you want to use DHCP, a DHCP server
155 must be operating on your network. Read
156 <file:Documentation/nfsroot.txt> for details.
158 config IP_PNP_BOOTP
159 bool "IP: BOOTP support"
160 depends on IP_PNP
161 ---help---
162 If you want your Linux box to mount its whole root file system (the
163 one containing the directory /) from some other computer over the
164 net via NFS and you want the IP address of your computer to be
165 discovered automatically at boot time using the BOOTP protocol (a
166 special protocol designed for doing this job), say Y here. In case
167 the boot ROM of your network card was designed for booting Linux and
168 does BOOTP itself, providing all necessary information on the kernel
169 command line, you can say N here. If unsure, say Y. Note that if you
170 want to use BOOTP, a BOOTP server must be operating on your network.
171 Read <file:Documentation/nfsroot.txt> for details.
173 config IP_PNP_RARP
174 bool "IP: RARP support"
175 depends on IP_PNP
176 help
177 If you want your Linux box to mount its whole root file system (the
178 one containing the directory /) from some other computer over the
179 net via NFS and you want the IP address of your computer to be
180 discovered automatically at boot time using the RARP protocol (an
181 older protocol which is being obsoleted by BOOTP and DHCP), say Y
182 here. Note that if you want to use RARP, a RARP server must be
183 operating on your network. Read <file:Documentation/nfsroot.txt> for
184 details.
186 # not yet ready..
187 # bool ' IP: ARP support' CONFIG_IP_PNP_ARP
188 config NET_IPIP
189 tristate "IP: tunneling"
190 select INET_TUNNEL
191 ---help---
192 Tunneling means encapsulating data of one protocol type within
193 another protocol and sending it over a channel that understands the
194 encapsulating protocol. This particular tunneling driver implements
195 encapsulation of IP within IP, which sounds kind of pointless, but
196 can be useful if you want to make your (or some other) machine
197 appear on a different network than it physically is, or to use
198 mobile-IP facilities (allowing laptops to seamlessly move between
199 networks without changing their IP addresses).
201 Saying Y to this option will produce two modules ( = code which can
202 be inserted in and removed from the running kernel whenever you
203 want). Most people won't need this and can say N.
205 config NET_IPGRE_DEMUX
206 tristate "IP: GRE demultiplexer"
207 help
208 This is helper module to demultiplex GRE packets on GRE version field criteria.
209 Required by ip-gre and pptp modules.
211 config NET_IPGRE
212 tristate "IP: GRE tunnels over IP"
213 depends on NET_IPGRE_DEMUX
214 help
215 Tunneling means encapsulating data of one protocol type within
216 another protocol and sending it over a channel that understands the
217 encapsulating protocol. This particular tunneling driver implements
218 GRE (Generic Routing Encapsulation) and at this time allows
219 encapsulating of IPv4 or IPv6 over existing IPv4 infrastructure.
220 This driver is useful if the other endpoint is a Cisco router: Cisco
221 likes GRE much better than the other Linux tunneling driver ("IP
222 tunneling" above). In addition, GRE allows multicast redistribution
223 through the tunnel.
225 config NET_IPGRE_BROADCAST
226 bool "IP: broadcast GRE over IP"
227 depends on IP_MULTICAST && NET_IPGRE
228 help
229 One application of GRE/IP is to construct a broadcast WAN (Wide Area
230 Network), which looks like a normal Ethernet LAN (Local Area
231 Network), but can be distributed all over the Internet. If you want
232 to do that, say Y here and to "IP multicast routing" below.
234 config IPSEC_NAT_TRAVERSAL
235 bool "IPSEC NAT-Traversal (KLIPS compatible)"
236 depends on INET
237 ---help---
238 Includes support for RFC3947/RFC3948 NAT-Traversal of ESP over UDP.
240 config IP_MROUTE
241 bool "IP: multicast routing"
242 depends on IP_MULTICAST
243 help
244 This is used if you want your machine to act as a router for IP
245 packets that have several destination addresses. It is needed on the
246 MBONE, a high bandwidth network on top of the Internet which carries
247 audio and video broadcasts. In order to do that, you would most
248 likely run the program mrouted. Information about the multicast
249 capabilities of the various network cards is contained in
250 <file:Documentation/networking/multicast.txt>. If you haven't heard
251 about it, you don't need it.
253 config IP_PIMSM_V1
254 bool "IP: PIM-SM version 1 support"
255 depends on IP_MROUTE
256 help
257 Kernel side support for Sparse Mode PIM (Protocol Independent
258 Multicast) version 1. This multicast routing protocol is used widely
259 because Cisco supports it. You need special software to use it
260 (pimd-v1). Please see <http://netweb.usc.edu/pim/> for more
261 information about PIM.
263 Say Y if you want to use PIM-SM v1. Note that you can say N here if
264 you just want to use Dense Mode PIM.
266 config IP_PIMSM_V2
267 bool "IP: PIM-SM version 2 support"
268 depends on IP_MROUTE
269 help
270 Kernel side support for Sparse Mode PIM version 2. In order to use
271 this, you need an experimental routing daemon supporting it (pimd or
272 gated-5). This routing protocol is not used widely, so say N unless
273 you want to play with it.
275 config ARPD
276 bool "IP: ARP daemon support (EXPERIMENTAL)"
277 depends on EXPERIMENTAL
278 ---help---
279 Normally, the kernel maintains an internal cache which maps IP
280 addresses to hardware addresses on the local network, so that
281 Ethernet/Token Ring/ etc. frames are sent to the proper address on
282 the physical networking layer. For small networks having a few
283 hundred directly connected hosts or less, keeping this address
284 resolution (ARP) cache inside the kernel works well. However,
285 maintaining an internal ARP cache does not work well for very large
286 switched networks, and will use a lot of kernel memory if TCP/IP
287 connections are made to many machines on the network.
289 If you say Y here, the kernel's internal ARP cache will never grow
290 to more than 256 entries (the oldest entries are expired in a LIFO
291 manner) and communication will be attempted with the user space ARP
292 daemon arpd. Arpd then answers the address resolution request either
293 from its own cache or by asking the net.
295 This code is experimental and also obsolete. If you want to use it,
296 you need to find a version of the daemon arpd on the net somewhere,
297 and you should also say Y to "Kernel/User network link driver",
298 below. If unsure, say N.
300 config SYN_COOKIES
301 bool "IP: TCP syncookie support (disabled per default)"
302 ---help---
303 Normal TCP/IP networking is open to an attack known as "SYN
304 flooding". This denial-of-service attack prevents legitimate remote
305 users from being able to connect to your computer during an ongoing
306 attack and requires very little work from the attacker, who can
307 operate from anywhere on the Internet.
309 SYN cookies provide protection against this type of attack. If you
310 say Y here, the TCP/IP stack will use a cryptographic challenge
311 protocol known as "SYN cookies" to enable legitimate users to
312 continue to connect, even when your machine is under attack. There
313 is no need for the legitimate users to change their TCP/IP software;
314 SYN cookies work transparently to them. For technical information
315 about SYN cookies, check out <http://cr.yp.to/syncookies.html>.
317 If you are SYN flooded, the source address reported by the kernel is
318 likely to have been forged by the attacker; it is only reported as
319 an aid in tracing the packets to their actual source and should not
320 be taken as absolute truth.
322 SYN cookies may prevent correct error reporting on clients when the
323 server is really overloaded. If this happens frequently better turn
324 them off.
326 If you say Y here, note that SYN cookies aren't enabled by default;
327 you can enable them by saying Y to "/proc file system support" and
328 "Sysctl support" below and executing the command
330 echo 1 >/proc/sys/net/ipv4/tcp_syncookies
332 at boot time after the /proc file system has been mounted.
334 If unsure, say N.
336 config INET_AH
337 tristate "IP: AH transformation"
338 select XFRM
339 select CRYPTO
340 select CRYPTO_HMAC
341 select CRYPTO_MD5
342 select CRYPTO_SHA1
343 ---help---
344 Support for IPsec AH.
346 If unsure, say Y.
348 config INET_ESP
349 tristate "IP: ESP transformation"
350 select XFRM
351 select CRYPTO
352 select CRYPTO_HMAC
353 select CRYPTO_MD5
354 select CRYPTO_CBC
355 select CRYPTO_SHA1
356 select CRYPTO_DES
357 ---help---
358 Support for IPsec ESP.
360 If unsure, say Y.
362 config INET_IPCOMP
363 tristate "IP: IPComp transformation"
364 select XFRM
365 select INET_XFRM_TUNNEL
366 select CRYPTO
367 select CRYPTO_DEFLATE
368 ---help---
369 Support for IP Payload Compression Protocol (IPComp) (RFC3173),
370 typically needed for IPsec.
372 If unsure, say Y.
374 config INET_XFRM_TUNNEL
375 tristate
376 select INET_TUNNEL
377 default n
379 config INET_TUNNEL
380 tristate
381 default n
383 config INET_XFRM_MODE_TRANSPORT
384 tristate "IP: IPsec transport mode"
385 default y
386 select XFRM
387 ---help---
388 Support for IPsec transport mode.
390 If unsure, say Y.
392 config INET_XFRM_MODE_TUNNEL
393 tristate "IP: IPsec tunnel mode"
394 default y
395 select XFRM
396 ---help---
397 Support for IPsec tunnel mode.
399 If unsure, say Y.
401 config INET_XFRM_MODE_BEET
402 tristate "IP: IPsec BEET mode"
403 default y
404 select XFRM
405 ---help---
406 Support for IPsec BEET mode.
408 If unsure, say Y.
410 config INET_DIAG
411 tristate "INET: socket monitoring interface"
412 default y
413 ---help---
414 Support for INET (TCP, DCCP, etc) socket monitoring interface used by
415 native Linux tools such as ss. ss is included in iproute2, currently
416 downloadable at <http://linux-net.osdl.org/index.php/Iproute2>.
418 If unsure, say Y.
420 config INET_TCP_DIAG
421 depends on INET_DIAG
422 def_tristate INET_DIAG
424 menuconfig TCP_CONG_ADVANCED
425 bool "TCP: advanced congestion control"
426 ---help---
427 Support for selection of various TCP congestion control
428 modules.
430 Nearly all users can safely say no here, and a safe default
431 selection will be made (CUBIC with new Reno as a fallback).
433 If unsure, say N.
435 if TCP_CONG_ADVANCED
437 config TCP_CONG_BIC
438 tristate "Binary Increase Congestion (BIC) control"
439 default m
440 ---help---
441 BIC-TCP is a sender-side only change that ensures a linear RTT
442 fairness under large windows while offering both scalability and
443 bounded TCP-friendliness. The protocol combines two schemes
444 called additive increase and binary search increase. When the
445 congestion window is large, additive increase with a large
446 increment ensures linear RTT fairness as well as good
447 scalability. Under small congestion windows, binary search
448 increase provides TCP friendliness.
449 See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/
451 config TCP_CONG_CUBIC
452 tristate "CUBIC TCP"
453 default y
454 ---help---
455 This is version 2.0 of BIC-TCP which uses a cubic growth function
456 among other techniques.
457 See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/cubic-paper.pdf
459 config TCP_CONG_WESTWOOD
460 tristate "TCP Westwood+"
461 default m
462 ---help---
463 TCP Westwood+ is a sender-side only modification of the TCP Reno
464 protocol stack that optimizes the performance of TCP congestion
465 control. It is based on end-to-end bandwidth estimation to set
466 congestion window and slow start threshold after a congestion
467 episode. Using this estimation, TCP Westwood+ adaptively sets a
468 slow start threshold and a congestion window which takes into
469 account the bandwidth used at the time congestion is experienced.
470 TCP Westwood+ significantly increases fairness wrt TCP Reno in
471 wired networks and throughput over wireless links.
473 config TCP_CONG_HTCP
474 tristate "H-TCP"
475 default m
476 ---help---
477 H-TCP is a send-side only modifications of the TCP Reno
478 protocol stack that optimizes the performance of TCP
479 congestion control for high speed network links. It uses a
480 modeswitch to change the alpha and beta parameters of TCP Reno
481 based on network conditions and in a way so as to be fair with
482 other Reno and H-TCP flows.
484 config TCP_CONG_HSTCP
485 tristate "High Speed TCP"
486 depends on EXPERIMENTAL
487 default n
488 ---help---
489 Sally Floyd's High Speed TCP (RFC 3649) congestion control.
490 A modification to TCP's congestion control mechanism for use
491 with large congestion windows. A table indicates how much to
492 increase the congestion window by when an ACK is received.
493 For more detail see http://www.icir.org/floyd/hstcp.html
495 config TCP_CONG_HYBLA
496 tristate "TCP-Hybla congestion control algorithm"
497 depends on EXPERIMENTAL
498 default n
499 ---help---
500 TCP-Hybla is a sender-side only change that eliminates penalization of
501 long-RTT, large-bandwidth connections, like when satellite legs are
502 involved, especially when sharing a common bottleneck with normal
503 terrestrial connections.
505 config TCP_CONG_VEGAS
506 tristate "TCP Vegas"
507 depends on EXPERIMENTAL
508 default n
509 ---help---
510 TCP Vegas is a sender-side only change to TCP that anticipates
511 the onset of congestion by estimating the bandwidth. TCP Vegas
512 adjusts the sending rate by modifying the congestion
513 window. TCP Vegas should provide less packet loss, but it is
514 not as aggressive as TCP Reno.
516 config TCP_CONG_SCALABLE
517 tristate "Scalable TCP"
518 depends on EXPERIMENTAL
519 default n
520 ---help---
521 Scalable TCP is a sender-side only change to TCP which uses a
522 MIMD congestion control algorithm which has some nice scaling
523 properties, though is known to have fairness issues.
524 See http://www.deneholme.net/tom/scalable/
526 config TCP_CONG_LP
527 tristate "TCP Low Priority"
528 depends on EXPERIMENTAL
529 default n
530 ---help---
531 TCP Low Priority (TCP-LP), a distributed algorithm whose goal is
532 to utilize only the excess network bandwidth as compared to the
533 ``fair share`` of bandwidth as targeted by TCP.
534 See http://www-ece.rice.edu/networks/TCP-LP/
536 config TCP_CONG_VENO
537 tristate "TCP Veno"
538 depends on EXPERIMENTAL
539 default n
540 ---help---
541 TCP Veno is a sender-side only enhancement of TCP to obtain better
542 throughput over wireless networks. TCP Veno makes use of state
543 distinguishing to circumvent the difficult judgment of the packet loss
544 type. TCP Veno cuts down less congestion window in response to random
545 loss packets.
546 See http://www.ntu.edu.sg/home5/ZHOU0022/papers/CPFu03a.pdf
548 config TCP_CONG_YEAH
549 tristate "YeAH TCP"
550 depends on EXPERIMENTAL
551 select TCP_CONG_VEGAS
552 default n
553 ---help---
554 YeAH-TCP is a sender-side high-speed enabled TCP congestion control
555 algorithm, which uses a mixed loss/delay approach to compute the
556 congestion window. It's design goals target high efficiency,
557 internal, RTT and Reno fairness, resilience to link loss while
558 keeping network elements load as low as possible.
560 For further details look here:
561 http://wil.cs.caltech.edu/pfldnet2007/paper/YeAH_TCP.pdf
563 config TCP_CONG_ILLINOIS
564 tristate "TCP Illinois"
565 depends on EXPERIMENTAL
566 default n
567 ---help---
568 TCP-Illinois is a sender-side modificatio of TCP Reno for
569 high speed long delay links. It uses round-trip-time to
570 adjust the alpha and beta parameters to achieve a higher average
571 throughput and maintain fairness.
573 For further details see:
574 http://www.ews.uiuc.edu/~shaoliu/tcpillinois/index.html
576 choice
577 prompt "Default TCP congestion control"
578 default DEFAULT_CUBIC
579 help
580 Select the TCP congestion control that will be used by default
581 for all connections.
583 config DEFAULT_BIC
584 bool "Bic" if TCP_CONG_BIC=y
586 config DEFAULT_CUBIC
587 bool "Cubic" if TCP_CONG_CUBIC=y
589 config DEFAULT_HTCP
590 bool "Htcp" if TCP_CONG_HTCP=y
592 config DEFAULT_VEGAS
593 bool "Vegas" if TCP_CONG_VEGAS=y
595 config DEFAULT_WESTWOOD
596 bool "Westwood" if TCP_CONG_WESTWOOD=y
598 config DEFAULT_RENO
599 bool "Reno"
601 endchoice
603 endif
605 config TCP_CONG_CUBIC
606 tristate
607 depends on !TCP_CONG_ADVANCED
608 default y
610 config DEFAULT_TCP_CONG
611 string
612 default "bic" if DEFAULT_BIC
613 default "cubic" if DEFAULT_CUBIC
614 default "htcp" if DEFAULT_HTCP
615 default "vegas" if DEFAULT_VEGAS
616 default "westwood" if DEFAULT_WESTWOOD
617 default "reno" if DEFAULT_RENO
618 default "cubic"
620 config TCP_MD5SIG
621 bool "TCP: MD5 Signature Option support (RFC2385) (EXPERIMENTAL)"
622 depends on EXPERIMENTAL
623 select CRYPTO
624 select CRYPTO_MD5
625 ---help---
626 RFC2385 specifies a method of giving MD5 protection to TCP sessions.
627 Its main (only?) use is to protect BGP sessions between core routers
628 on the Internet.
630 If unsure, say N.
632 source "net/ipv4/ipvs/Kconfig"