| blob | 5b919f7b45db4db2e263ed7a43f82e2ed9a382af |
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 should consider 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 and
50 echo 1 > /proc/sys/net/ipv4/conf/all/rp_filter
52 Note that some distributions enable it in startup scripts.
53 For details about rp_filter strict and loose mode read
54 <file:Documentation/networking/ip-sysctl.txt>.
56 If unsure, say N here.
58 choice
59 prompt "Choose IP: FIB lookup algorithm (choose FIB_HASH if unsure)"
60 depends on IP_ADVANCED_ROUTER
61 default ASK_IP_FIB_HASH
63 config ASK_IP_FIB_HASH
64 bool "FIB_HASH"
65 ---help---
66 Current FIB is very proven and good enough for most users.
68 config IP_FIB_TRIE
69 bool "FIB_TRIE"
70 ---help---
71 Use new experimental LC-trie as FIB lookup algorithm.
72 This improves lookup performance if you have a large
73 number of routes.
75 LC-trie is a longest matching prefix lookup algorithm which
76 performs better than FIB_HASH for large routing tables.
77 But, it consumes more memory and is more complex.
79 LC-trie is described in:
81 IP-address lookup using LC-tries. Stefan Nilsson and Gunnar Karlsson
82 IEEE Journal on Selected Areas in Communications, 17(6):1083-1092,
83 June 1999
85 An experimental study of compression methods for dynamic tries
86 Stefan Nilsson and Matti Tikkanen. Algorithmica, 33(1):19-33, 2002.
87 http://www.nada.kth.se/~snilsson/public/papers/dyntrie2/
89 endchoice
91 config IP_FIB_HASH
92 def_bool ASK_IP_FIB_HASH || !IP_ADVANCED_ROUTER
94 config IP_FIB_TRIE_STATS
95 bool "FIB TRIE statistics"
96 depends on IP_FIB_TRIE
97 ---help---
98 Keep track of statistics on structure of FIB TRIE table.
99 Useful for testing and measuring TRIE performance.
101 config IP_MULTIPLE_TABLES
102 bool "IP: policy routing"
103 depends on IP_ADVANCED_ROUTER
104 select FIB_RULES
105 ---help---
106 Normally, a router decides what to do with a received packet based
107 solely on the packet's final destination address. If you say Y here,
108 the Linux router will also be able to take the packet's source
109 address into account. Furthermore, the TOS (Type-Of-Service) field
110 of the packet can be used for routing decisions as well.
112 If you are interested in this, please see the preliminary
113 documentation at <http://www.compendium.com.ar/policy-routing.txt>
114 and <ftp://post.tepkom.ru/pub/vol2/Linux/docs/advanced-routing.tex>.
115 You will need supporting software from
116 <ftp://ftp.tux.org/pub/net/ip-routing/>.
118 If unsure, say N.
120 config IP_ROUTE_MULTIPATH
121 bool "IP: equal cost multipath"
122 depends on IP_ADVANCED_ROUTER
123 help
124 Normally, the routing tables specify a single action to be taken in
125 a deterministic manner for a given packet. If you say Y here
126 however, it becomes possible to attach several actions to a packet
127 pattern, in effect specifying several alternative paths to travel
128 for those packets. The router considers all these paths to be of
129 equal "cost" and chooses one of them in a non-deterministic fashion
130 if a matching packet arrives.
132 config IP_ROUTE_VERBOSE
133 bool "IP: verbose route monitoring"
134 depends on IP_ADVANCED_ROUTER
135 help
136 If you say Y here, which is recommended, then the kernel will print
137 verbose messages regarding the routing, for example warnings about
138 received packets which look strange and could be evidence of an
139 attack or a misconfigured system somewhere. The information is
140 handled by the klogd daemon which is responsible for kernel messages
141 ("man klogd").
143 config IP_PNP
144 bool "IP: kernel level autoconfiguration"
145 help
146 This enables automatic configuration of IP addresses of devices and
147 of the routing table during kernel boot, based on either information
148 supplied on the kernel command line or by BOOTP or RARP protocols.
149 You need to say Y only for diskless machines requiring network
150 access to boot (in which case you want to say Y to "Root file system
151 on NFS" as well), because all other machines configure the network
152 in their startup scripts.
154 config IP_PNP_DHCP
155 bool "IP: DHCP support"
156 depends on IP_PNP
157 ---help---
158 If you want your Linux box to mount its whole root file system (the
159 one containing the directory /) from some other computer over the
160 net via NFS and you want the IP address of your computer to be
161 discovered automatically at boot time using the DHCP protocol (a
162 special protocol designed for doing this job), say Y here. In case
163 the boot ROM of your network card was designed for booting Linux and
164 does DHCP itself, providing all necessary information on the kernel
165 command line, you can say N here.
167 If unsure, say Y. Note that if you want to use DHCP, a DHCP server
168 must be operating on your network. Read
169 <file:Documentation/filesystems/nfsroot.txt> for details.
171 config IP_PNP_BOOTP
172 bool "IP: BOOTP support"
173 depends on IP_PNP
174 ---help---
175 If you want your Linux box to mount its whole root file system (the
176 one containing the directory /) from some other computer over the
177 net via NFS and you want the IP address of your computer to be
178 discovered automatically at boot time using the BOOTP protocol (a
179 special protocol designed for doing this job), say Y here. In case
180 the boot ROM of your network card was designed for booting Linux and
181 does BOOTP itself, providing all necessary information on the kernel
182 command line, you can say N here. If unsure, say Y. Note that if you
183 want to use BOOTP, a BOOTP server must be operating on your network.
184 Read <file:Documentation/filesystems/nfsroot.txt> for details.
186 config IP_PNP_RARP
187 bool "IP: RARP support"
188 depends on IP_PNP
189 help
190 If you want your Linux box to mount its whole root file system (the
191 one containing the directory /) from some other computer over the
192 net via NFS and you want the IP address of your computer to be
193 discovered automatically at boot time using the RARP protocol (an
194 older protocol which is being obsoleted by BOOTP and DHCP), say Y
195 here. Note that if you want to use RARP, a RARP server must be
196 operating on your network. Read
197 <file:Documentation/filesystems/nfsroot.txt> for details.
199 # not yet ready..
200 # bool ' IP: ARP support' CONFIG_IP_PNP_ARP
201 config NET_IPIP
202 tristate "IP: tunneling"
203 select INET_TUNNEL
204 ---help---
205 Tunneling means encapsulating data of one protocol type within
206 another protocol and sending it over a channel that understands the
207 encapsulating protocol. This particular tunneling driver implements
208 encapsulation of IP within IP, which sounds kind of pointless, but
209 can be useful if you want to make your (or some other) machine
210 appear on a different network than it physically is, or to use
211 mobile-IP facilities (allowing laptops to seamlessly move between
212 networks without changing their IP addresses).
214 Saying Y to this option will produce two modules ( = code which can
215 be inserted in and removed from the running kernel whenever you
216 want). Most people won't need this and can say N.
218 config NET_IPGRE
219 tristate "IP: GRE tunnels over IP"
220 help
221 Tunneling means encapsulating data of one protocol type within
222 another protocol and sending it over a channel that understands the
223 encapsulating protocol. This particular tunneling driver implements
224 GRE (Generic Routing Encapsulation) and at this time allows
225 encapsulating of IPv4 or IPv6 over existing IPv4 infrastructure.
226 This driver is useful if the other endpoint is a Cisco router: Cisco
227 likes GRE much better than the other Linux tunneling driver ("IP
228 tunneling" above). In addition, GRE allows multicast redistribution
229 through the tunnel.
231 config NET_IPGRE_BROADCAST
232 bool "IP: broadcast GRE over IP"
233 depends on IP_MULTICAST && NET_IPGRE
234 help
235 One application of GRE/IP is to construct a broadcast WAN (Wide Area
236 Network), which looks like a normal Ethernet LAN (Local Area
237 Network), but can be distributed all over the Internet. If you want
238 to do that, say Y here and to "IP multicast routing" below.
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_AUTHENC
353 select CRYPTO_HMAC
354 select CRYPTO_MD5
355 select CRYPTO_CBC
356 select CRYPTO_SHA1
357 select CRYPTO_DES
358 ---help---
359 Support for IPsec ESP.
361 If unsure, say Y.
363 config INET_IPCOMP
364 tristate "IP: IPComp transformation"
365 select INET_XFRM_TUNNEL
366 select XFRM_IPCOMP
367 ---help---
368 Support for IP Payload Compression Protocol (IPComp) (RFC3173),
369 typically needed for IPsec.
371 If unsure, say Y.
373 config INET_XFRM_TUNNEL
374 tristate
375 select INET_TUNNEL
376 default n
378 config INET_TUNNEL
379 tristate
380 default n
382 config INET_XFRM_MODE_TRANSPORT
383 tristate "IP: IPsec transport mode"
384 default y
385 select XFRM
386 ---help---
387 Support for IPsec transport mode.
389 If unsure, say Y.
391 config INET_XFRM_MODE_TUNNEL
392 tristate "IP: IPsec tunnel mode"
393 default y
394 select XFRM
395 ---help---
396 Support for IPsec tunnel mode.
398 If unsure, say Y.
400 config INET_XFRM_MODE_BEET
401 tristate "IP: IPsec BEET mode"
402 default y
403 select XFRM
404 ---help---
405 Support for IPsec BEET mode.
407 If unsure, say Y.
409 config INET_LRO
410 bool "Large Receive Offload (ipv4/tcp)"
411 default y
412 ---help---
413 Support for Large Receive Offload (ipv4/tcp).
415 If unsure, say Y.
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://linux-net.osdl.org/index.php/Iproute2>.
425 If unsure, say Y.
427 config INET_TCP_DIAG
428 depends on INET_DIAG
429 def_tristate INET_DIAG
431 menuconfig 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 (CUBIC with new Reno as a fallback).
440 If unsure, say N.
442 if TCP_CONG_ADVANCED
444 config TCP_CONG_BIC
445 tristate "Binary Increase Congestion (BIC) control"
446 default m
447 ---help---
448 BIC-TCP is a sender-side only change that ensures a linear RTT
449 fairness under large windows while offering both scalability and
450 bounded TCP-friendliness. The protocol combines two schemes
451 called additive increase and binary search increase. When the
452 congestion window is large, additive increase with a large
453 increment ensures linear RTT fairness as well as good
454 scalability. Under small congestion windows, binary search
455 increase provides TCP friendliness.
456 See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/
458 config TCP_CONG_CUBIC
459 tristate "CUBIC TCP"
460 default y
461 ---help---
462 This is version 2.0 of BIC-TCP which uses a cubic growth function
463 among other techniques.
464 See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/cubic-paper.pdf
466 config TCP_CONG_WESTWOOD
467 tristate "TCP Westwood+"
468 default m
469 ---help---
470 TCP Westwood+ is a sender-side only modification of the TCP Reno
471 protocol stack that optimizes the performance of TCP congestion
472 control. It is based on end-to-end bandwidth estimation to set
473 congestion window and slow start threshold after a congestion
474 episode. Using this estimation, TCP Westwood+ adaptively sets a
475 slow start threshold and a congestion window which takes into
476 account the bandwidth used at the time congestion is experienced.
477 TCP Westwood+ significantly increases fairness wrt TCP Reno in
478 wired networks and throughput over wireless links.
480 config TCP_CONG_HTCP
481 tristate "H-TCP"
482 default m
483 ---help---
484 H-TCP is a send-side only modifications of the TCP Reno
485 protocol stack that optimizes the performance of TCP
486 congestion control for high speed network links. It uses a
487 modeswitch to change the alpha and beta parameters of TCP Reno
488 based on network conditions and in a way so as to be fair with
489 other Reno and H-TCP flows.
491 config TCP_CONG_HSTCP
492 tristate "High Speed TCP"
493 depends on EXPERIMENTAL
494 default n
495 ---help---
496 Sally Floyd's High Speed TCP (RFC 3649) congestion control.
497 A modification to TCP's congestion control mechanism for use
498 with large congestion windows. A table indicates how much to
499 increase the congestion window by when an ACK is received.
500 For more detail see http://www.icir.org/floyd/hstcp.html
502 config TCP_CONG_HYBLA
503 tristate "TCP-Hybla congestion control algorithm"
504 depends on EXPERIMENTAL
505 default n
506 ---help---
507 TCP-Hybla is a sender-side only change that eliminates penalization of
508 long-RTT, large-bandwidth connections, like when satellite legs are
509 involved, especially when sharing a common bottleneck with normal
510 terrestrial connections.
512 config TCP_CONG_VEGAS
513 tristate "TCP Vegas"
514 depends on EXPERIMENTAL
515 default n
516 ---help---
517 TCP Vegas is a sender-side only change to TCP that anticipates
518 the onset of congestion by estimating the bandwidth. TCP Vegas
519 adjusts the sending rate by modifying the congestion
520 window. TCP Vegas should provide less packet loss, but it is
521 not as aggressive as TCP Reno.
523 config TCP_CONG_SCALABLE
524 tristate "Scalable TCP"
525 depends on EXPERIMENTAL
526 default n
527 ---help---
528 Scalable TCP is a sender-side only change to TCP which uses a
529 MIMD congestion control algorithm which has some nice scaling
530 properties, though is known to have fairness issues.
531 See http://www.deneholme.net/tom/scalable/
533 config TCP_CONG_LP
534 tristate "TCP Low Priority"
535 depends on EXPERIMENTAL
536 default n
537 ---help---
538 TCP Low Priority (TCP-LP), a distributed algorithm whose goal is
539 to utilize only the excess network bandwidth as compared to the
540 ``fair share`` of bandwidth as targeted by TCP.
541 See http://www-ece.rice.edu/networks/TCP-LP/
543 config TCP_CONG_VENO
544 tristate "TCP Veno"
545 depends on EXPERIMENTAL
546 default n
547 ---help---
548 TCP Veno is a sender-side only enhancement of TCP to obtain better
549 throughput over wireless networks. TCP Veno makes use of state
550 distinguishing to circumvent the difficult judgment of the packet loss
551 type. TCP Veno cuts down less congestion window in response to random
552 loss packets.
553 See http://www.ntu.edu.sg/home5/ZHOU0022/papers/CPFu03a.pdf
555 config TCP_CONG_YEAH
556 tristate "YeAH TCP"
557 depends on EXPERIMENTAL
558 select TCP_CONG_VEGAS
559 default n
560 ---help---
561 YeAH-TCP is a sender-side high-speed enabled TCP congestion control
562 algorithm, which uses a mixed loss/delay approach to compute the
563 congestion window. It's design goals target high efficiency,
564 internal, RTT and Reno fairness, resilience to link loss while
565 keeping network elements load as low as possible.
567 For further details look here:
568 http://wil.cs.caltech.edu/pfldnet2007/paper/YeAH_TCP.pdf
570 config TCP_CONG_ILLINOIS
571 tristate "TCP Illinois"
572 depends on EXPERIMENTAL
573 default n
574 ---help---
575 TCP-Illinois is a sender-side modification of TCP Reno for
576 high speed long delay links. It uses round-trip-time to
577 adjust the alpha and beta parameters to achieve a higher average
578 throughput and maintain fairness.
580 For further details see:
581 http://www.ews.uiuc.edu/~shaoliu/tcpillinois/index.html
583 choice
584 prompt "Default TCP congestion control"
585 default DEFAULT_CUBIC
586 help
587 Select the TCP congestion control that will be used by default
588 for all connections.
590 config DEFAULT_BIC
591 bool "Bic" if TCP_CONG_BIC=y
593 config DEFAULT_CUBIC
594 bool "Cubic" if TCP_CONG_CUBIC=y
596 config DEFAULT_HTCP
597 bool "Htcp" if TCP_CONG_HTCP=y
599 config DEFAULT_VEGAS
600 bool "Vegas" if TCP_CONG_VEGAS=y
602 config DEFAULT_WESTWOOD
603 bool "Westwood" if TCP_CONG_WESTWOOD=y
605 config DEFAULT_RENO
606 bool "Reno"
608 endchoice
610 endif
612 config TCP_CONG_CUBIC
613 tristate
614 depends on !TCP_CONG_ADVANCED
615 default y
617 config DEFAULT_TCP_CONG
618 string
619 default "bic" if DEFAULT_BIC
620 default "cubic" if DEFAULT_CUBIC
621 default "htcp" if DEFAULT_HTCP
622 default "vegas" if DEFAULT_VEGAS
623 default "westwood" if DEFAULT_WESTWOOD
624 default "reno" if DEFAULT_RENO
625 default "cubic"
627 config TCP_MD5SIG
628 bool "TCP: MD5 Signature Option support (RFC2385) (EXPERIMENTAL)"
629 depends on EXPERIMENTAL
630 select CRYPTO
631 select CRYPTO_MD5
632 ---help---
633 RFC2385 specifies a method of giving MD5 protection to TCP sessions.
634 Its main (only?) use is to protect BGP sessions between core routers
635 on the Internet.
637 If unsure, say N.