1
2
3
4config 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/>. For most people, it's safe to say N.
13
14config IP_ADVANCED_ROUTER
15 bool "IP: advanced router"
16 ---help---
17 If you intend to run your Linux box mostly as a router, i.e. as a
18 computer that forwards and redistributes network packets, say Y; you
19 will then be presented with several options that allow more precise
20 control about the routing process.
21
22 The answer to this question won't directly affect the kernel:
23 answering N will just cause the configurator to skip all the
24 questions about advanced routing.
25
26 Note that your box can only act as a router if you enable IP
27 forwarding in your kernel; you can do that by saying Y to "/proc
28 file system support" and "Sysctl support" below and executing the
29 line
30
31 echo "1" > /proc/sys/net/ipv4/ip_forward
32
33 at boot time after the /proc file system has been mounted.
34
35 If you turn on IP forwarding, you should consider the rp_filter, which
36 automatically rejects incoming packets if the routing table entry
37 for their source address doesn't match the network interface they're
38 arriving on. This has security advantages because it prevents the
39 so-called IP spoofing, however it can pose problems if you use
40 asymmetric routing (packets from you to a host take a different path
41 than packets from that host to you) or if you operate a non-routing
42 host which has several IP addresses on different interfaces. To turn
43 rp_filter on use:
44
45 echo 1 > /proc/sys/net/ipv4/conf/<device>/rp_filter
46 or
47 echo 1 > /proc/sys/net/ipv4/conf/all/rp_filter
48
49 Note that some distributions enable it in startup scripts.
50 For details about rp_filter strict and loose mode read
51 <file:Documentation/networking/ip-sysctl.txt>.
52
53 If unsure, say N here.
54
55config IP_FIB_TRIE_STATS
56 bool "FIB TRIE statistics"
57 depends on IP_ADVANCED_ROUTER
58 ---help---
59 Keep track of statistics on structure of FIB TRIE table.
60 Useful for testing and measuring TRIE performance.
61
62config IP_MULTIPLE_TABLES
63 bool "IP: policy routing"
64 depends on IP_ADVANCED_ROUTER
65 select FIB_RULES
66 ---help---
67 Normally, a router decides what to do with a received packet based
68 solely on the packet's final destination address. If you say Y here,
69 the Linux router will also be able to take the packet's source
70 address into account. Furthermore, the TOS (Type-Of-Service) field
71 of the packet can be used for routing decisions as well.
72
73 If you are interested in this, please see the preliminary
74 documentation at <http://www.compendium.com.ar/policy-routing.txt>
75 and <ftp://post.tepkom.ru/pub/vol2/Linux/docs/advanced-routing.tex>.
76 You will need supporting software from
77 <ftp://ftp.tux.org/pub/net/ip-routing/>.
78
79 If unsure, say N.
80
81config IP_ROUTE_MULTIPATH
82 bool "IP: equal cost multipath"
83 depends on IP_ADVANCED_ROUTER
84 help
85 Normally, the routing tables specify a single action to be taken in
86 a deterministic manner for a given packet. If you say Y here
87 however, it becomes possible to attach several actions to a packet
88 pattern, in effect specifying several alternative paths to travel
89 for those packets. The router considers all these paths to be of
90 equal "cost" and chooses one of them in a non-deterministic fashion
91 if a matching packet arrives.
92
93config IP_ROUTE_VERBOSE
94 bool "IP: verbose route monitoring"
95 depends on IP_ADVANCED_ROUTER
96 help
97 If you say Y here, which is recommended, then the kernel will print
98 verbose messages regarding the routing, for example warnings about
99 received packets which look strange and could be evidence of an
100 attack or a misconfigured system somewhere. The information is
101 handled by the klogd daemon which is responsible for kernel messages
102 ("man klogd").
103
104config IP_ROUTE_CLASSID
105 bool
106
107config IP_PNP
108 bool "IP: kernel level autoconfiguration"
109 help
110 This enables automatic configuration of IP addresses of devices and
111 of the routing table during kernel boot, based on either information
112 supplied on the kernel command line or by BOOTP or RARP protocols.
113 You need to say Y only for diskless machines requiring network
114 access to boot (in which case you want to say Y to "Root file system
115 on NFS" as well), because all other machines configure the network
116 in their startup scripts.
117
118config IP_PNP_DHCP
119 bool "IP: DHCP support"
120 depends on IP_PNP
121 ---help---
122 If you want your Linux box to mount its whole root file system (the
123 one containing the directory /) from some other computer over the
124 net via NFS and you want the IP address of your computer to be
125 discovered automatically at boot time using the DHCP protocol (a
126 special protocol designed for doing this job), say Y here. In case
127 the boot ROM of your network card was designed for booting Linux and
128 does DHCP itself, providing all necessary information on the kernel
129 command line, you can say N here.
130
131 If unsure, say Y. Note that if you want to use DHCP, a DHCP server
132 must be operating on your network. Read
133 <file:Documentation/filesystems/nfs/nfsroot.txt> for details.
134
135config IP_PNP_BOOTP
136 bool "IP: BOOTP support"
137 depends on IP_PNP
138 ---help---
139 If you want your Linux box to mount its whole root file system (the
140 one containing the directory /) from some other computer over the
141 net via NFS and you want the IP address of your computer to be
142 discovered automatically at boot time using the BOOTP protocol (a
143 special protocol designed for doing this job), say Y here. In case
144 the boot ROM of your network card was designed for booting Linux and
145 does BOOTP itself, providing all necessary information on the kernel
146 command line, you can say N here. If unsure, say Y. Note that if you
147 want to use BOOTP, a BOOTP server must be operating on your network.
148 Read <file:Documentation/filesystems/nfs/nfsroot.txt> for details.
149
150config IP_PNP_RARP
151 bool "IP: RARP support"
152 depends on IP_PNP
153 help
154 If you want your Linux box to mount its whole root file system (the
155 one containing the directory /) from some other computer over the
156 net via NFS and you want the IP address of your computer to be
157 discovered automatically at boot time using the RARP protocol (an
158 older protocol which is being obsoleted by BOOTP and DHCP), say Y
159 here. Note that if you want to use RARP, a RARP server must be
160 operating on your network. Read
161 <file:Documentation/filesystems/nfs/nfsroot.txt> for details.
162
163config NET_IPIP
164 tristate "IP: tunneling"
165 select INET_TUNNEL
166 select NET_IP_TUNNEL
167 ---help---
168 Tunneling means encapsulating data of one protocol type within
169 another protocol and sending it over a channel that understands the
170 encapsulating protocol. This particular tunneling driver implements
171 encapsulation of IP within IP, which sounds kind of pointless, but
172 can be useful if you want to make your (or some other) machine
173 appear on a different network than it physically is, or to use
174 mobile-IP facilities (allowing laptops to seamlessly move between
175 networks without changing their IP addresses).
176
177 Saying Y to this option will produce two modules ( = code which can
178 be inserted in and removed from the running kernel whenever you
179 want). Most people won't need this and can say N.
180
181config NET_IPGRE_DEMUX
182 tristate "IP: GRE demultiplexer"
183 help
184 This is helper module to demultiplex GRE packets on GRE version field criteria.
185 Required by ip_gre and pptp modules.
186
187config NET_IP_TUNNEL
188 tristate
189 default n
190
191config NET_IPGRE
192 tristate "IP: GRE tunnels over IP"
193 depends on (IPV6 || IPV6=n) && NET_IPGRE_DEMUX
194 select NET_IP_TUNNEL
195 help
196 Tunneling means encapsulating data of one protocol type within
197 another protocol and sending it over a channel that understands the
198 encapsulating protocol. This particular tunneling driver implements
199 GRE (Generic Routing Encapsulation) and at this time allows
200 encapsulating of IPv4 or IPv6 over existing IPv4 infrastructure.
201 This driver is useful if the other endpoint is a Cisco router: Cisco
202 likes GRE much better than the other Linux tunneling driver ("IP
203 tunneling" above). In addition, GRE allows multicast redistribution
204 through the tunnel.
205
206config NET_IPGRE_BROADCAST
207 bool "IP: broadcast GRE over IP"
208 depends on IP_MULTICAST && NET_IPGRE
209 help
210 One application of GRE/IP is to construct a broadcast WAN (Wide Area
211 Network), which looks like a normal Ethernet LAN (Local Area
212 Network), but can be distributed all over the Internet. If you want
213 to do that, say Y here and to "IP multicast routing" below.
214
215config IP_MROUTE
216 bool "IP: multicast routing"
217 depends on IP_MULTICAST
218 help
219 This is used if you want your machine to act as a router for IP
220 packets that have several destination addresses. It is needed on the
221 MBONE, a high bandwidth network on top of the Internet which carries
222 audio and video broadcasts. In order to do that, you would most
223 likely run the program mrouted. If you haven't heard about it, you
224 don't need it.
225
226config IP_MROUTE_MULTIPLE_TABLES
227 bool "IP: multicast policy routing"
228 depends on IP_MROUTE && IP_ADVANCED_ROUTER
229 select FIB_RULES
230 help
231 Normally, a multicast router runs a userspace daemon and decides
232 what to do with a multicast packet based on the source and
233 destination addresses. If you say Y here, the multicast router
234 will also be able to take interfaces and packet marks into
235 account and run multiple instances of userspace daemons
236 simultaneously, each one handling a single table.
237
238 If unsure, say N.
239
240config IP_PIMSM_V1
241 bool "IP: PIM-SM version 1 support"
242 depends on IP_MROUTE
243 help
244 Kernel side support for Sparse Mode PIM (Protocol Independent
245 Multicast) version 1. This multicast routing protocol is used widely
246 because Cisco supports it. You need special software to use it
247 (pimd-v1). Please see <http://netweb.usc.edu/pim/> for more
248 information about PIM.
249
250 Say Y if you want to use PIM-SM v1. Note that you can say N here if
251 you just want to use Dense Mode PIM.
252
253config IP_PIMSM_V2
254 bool "IP: PIM-SM version 2 support"
255 depends on IP_MROUTE
256 help
257 Kernel side support for Sparse Mode PIM version 2. In order to use
258 this, you need an experimental routing daemon supporting it (pimd or
259 gated-5). This routing protocol is not used widely, so say N unless
260 you want to play with it.
261
262config SYN_COOKIES
263 bool "IP: TCP syncookie support"
264 ---help---
265 Normal TCP/IP networking is open to an attack known as "SYN
266 flooding". This denial-of-service attack prevents legitimate remote
267 users from being able to connect to your computer during an ongoing
268 attack and requires very little work from the attacker, who can
269 operate from anywhere on the Internet.
270
271 SYN cookies provide protection against this type of attack. If you
272 say Y here, the TCP/IP stack will use a cryptographic challenge
273 protocol known as "SYN cookies" to enable legitimate users to
274 continue to connect, even when your machine is under attack. There
275 is no need for the legitimate users to change their TCP/IP software;
276 SYN cookies work transparently to them. For technical information
277 about SYN cookies, check out <http://cr.yp.to/syncookies.html>.
278
279 If you are SYN flooded, the source address reported by the kernel is
280 likely to have been forged by the attacker; it is only reported as
281 an aid in tracing the packets to their actual source and should not
282 be taken as absolute truth.
283
284 SYN cookies may prevent correct error reporting on clients when the
285 server is really overloaded. If this happens frequently better turn
286 them off.
287
288 If you say Y here, you can disable SYN cookies at run time by
289 saying Y to "/proc file system support" and
290 "Sysctl support" below and executing the command
291
292 echo 0 > /proc/sys/net/ipv4/tcp_syncookies
293
294 after the /proc file system has been mounted.
295
296 If unsure, say N.
297
298config NET_IPVTI
299 tristate "Virtual (secure) IP: tunneling"
300 select INET_TUNNEL
301 select NET_IP_TUNNEL
302 depends on INET_XFRM_MODE_TUNNEL
303 ---help---
304 Tunneling means encapsulating data of one protocol type within
305 another protocol and sending it over a channel that understands the
306 encapsulating protocol. This can be used with xfrm mode tunnel to give
307 the notion of a secure tunnel for IPSEC and then use routing protocol
308 on top.
309
310config INET_AH
311 tristate "IP: AH transformation"
312 select XFRM_ALGO
313 select CRYPTO
314 select CRYPTO_HMAC
315 select CRYPTO_MD5
316 select CRYPTO_SHA1
317 ---help---
318 Support for IPsec AH.
319
320 If unsure, say Y.
321
322config INET_ESP
323 tristate "IP: ESP transformation"
324 select XFRM_ALGO
325 select CRYPTO
326 select CRYPTO_AUTHENC
327 select CRYPTO_HMAC
328 select CRYPTO_MD5
329 select CRYPTO_CBC
330 select CRYPTO_SHA1
331 select CRYPTO_DES
332 ---help---
333 Support for IPsec ESP.
334
335 If unsure, say Y.
336
337config INET_IPCOMP
338 tristate "IP: IPComp transformation"
339 select INET_XFRM_TUNNEL
340 select XFRM_IPCOMP
341 ---help---
342 Support for IP Payload Compression Protocol (IPComp) (RFC3173),
343 typically needed for IPsec.
344
345 If unsure, say Y.
346
347config INET_XFRM_TUNNEL
348 tristate
349 select INET_TUNNEL
350 default n
351
352config INET_TUNNEL
353 tristate
354 default n
355
356config INET_XFRM_MODE_TRANSPORT
357 tristate "IP: IPsec transport mode"
358 default y
359 select XFRM
360 ---help---
361 Support for IPsec transport mode.
362
363 If unsure, say Y.
364
365config INET_XFRM_MODE_TUNNEL
366 tristate "IP: IPsec tunnel mode"
367 default y
368 select XFRM
369 ---help---
370 Support for IPsec tunnel mode.
371
372 If unsure, say Y.
373
374config INET_XFRM_MODE_BEET
375 tristate "IP: IPsec BEET mode"
376 default y
377 select XFRM
378 ---help---
379 Support for IPsec BEET mode.
380
381 If unsure, say Y.
382
383config INET_LRO
384 tristate "Large Receive Offload (ipv4/tcp)"
385 default y
386 ---help---
387 Support for Large Receive Offload (ipv4/tcp).
388
389 If unsure, say Y.
390
391config INET_DIAG
392 tristate "INET: socket monitoring interface"
393 default y
394 ---help---
395 Support for INET (TCP, DCCP, etc) socket monitoring interface used by
396 native Linux tools such as ss. ss is included in iproute2, currently
397 downloadable at:
398
399 http://www.linuxfoundation.org/collaborate/workgroups/networking/iproute2
400
401 If unsure, say Y.
402
403config INET_TCP_DIAG
404 depends on INET_DIAG
405 def_tristate INET_DIAG
406
407config INET_UDP_DIAG
408 tristate "UDP: socket monitoring interface"
409 depends on INET_DIAG && (IPV6 || IPV6=n)
410 default n
411 ---help---
412 Support for UDP socket monitoring interface used by the ss tool.
413 If unsure, say Y.
414
415menuconfig TCP_CONG_ADVANCED
416 bool "TCP: advanced congestion control"
417 ---help---
418 Support for selection of various TCP congestion control
419 modules.
420
421 Nearly all users can safely say no here, and a safe default
422 selection will be made (CUBIC with new Reno as a fallback).
423
424 If unsure, say N.
425
426if TCP_CONG_ADVANCED
427
428config TCP_CONG_BIC
429 tristate "Binary Increase Congestion (BIC) control"
430 default m
431 ---help---
432 BIC-TCP is a sender-side only change that ensures a linear RTT
433 fairness under large windows while offering both scalability and
434 bounded TCP-friendliness. The protocol combines two schemes
435 called additive increase and binary search increase. When the
436 congestion window is large, additive increase with a large
437 increment ensures linear RTT fairness as well as good
438 scalability. Under small congestion windows, binary search
439 increase provides TCP friendliness.
440 See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/
441
442config TCP_CONG_CUBIC
443 tristate "CUBIC TCP"
444 default y
445 ---help---
446 This is version 2.0 of BIC-TCP which uses a cubic growth function
447 among other techniques.
448 See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/cubic-paper.pdf
449
450config TCP_CONG_WESTWOOD
451 tristate "TCP Westwood+"
452 default m
453 ---help---
454 TCP Westwood+ is a sender-side only modification of the TCP Reno
455 protocol stack that optimizes the performance of TCP congestion
456 control. It is based on end-to-end bandwidth estimation to set
457 congestion window and slow start threshold after a congestion
458 episode. Using this estimation, TCP Westwood+ adaptively sets a
459 slow start threshold and a congestion window which takes into
460 account the bandwidth used at the time congestion is experienced.
461 TCP Westwood+ significantly increases fairness wrt TCP Reno in
462 wired networks and throughput over wireless links.
463
464config TCP_CONG_HTCP
465 tristate "H-TCP"
466 default m
467 ---help---
468 H-TCP is a send-side only modifications of the TCP Reno
469 protocol stack that optimizes the performance of TCP
470 congestion control for high speed network links. It uses a
471 modeswitch to change the alpha and beta parameters of TCP Reno
472 based on network conditions and in a way so as to be fair with
473 other Reno and H-TCP flows.
474
475config TCP_CONG_HSTCP
476 tristate "High Speed TCP"
477 default n
478 ---help---
479 Sally Floyd's High Speed TCP (RFC 3649) congestion control.
480 A modification to TCP's congestion control mechanism for use
481 with large congestion windows. A table indicates how much to
482 increase the congestion window by when an ACK is received.
483 For more detail see http://www.icir.org/floyd/hstcp.html
484
485config TCP_CONG_HYBLA
486 tristate "TCP-Hybla congestion control algorithm"
487 default n
488 ---help---
489 TCP-Hybla is a sender-side only change that eliminates penalization of
490 long-RTT, large-bandwidth connections, like when satellite legs are
491 involved, especially when sharing a common bottleneck with normal
492 terrestrial connections.
493
494config TCP_CONG_VEGAS
495 tristate "TCP Vegas"
496 default n
497 ---help---
498 TCP Vegas is a sender-side only change to TCP that anticipates
499 the onset of congestion by estimating the bandwidth. TCP Vegas
500 adjusts the sending rate by modifying the congestion
501 window. TCP Vegas should provide less packet loss, but it is
502 not as aggressive as TCP Reno.
503
504config TCP_CONG_SCALABLE
505 tristate "Scalable TCP"
506 default n
507 ---help---
508 Scalable TCP is a sender-side only change to TCP which uses a
509 MIMD congestion control algorithm which has some nice scaling
510 properties, though is known to have fairness issues.
511 See http://www.deneholme.net/tom/scalable/
512
513config TCP_CONG_LP
514 tristate "TCP Low Priority"
515 default n
516 ---help---
517 TCP Low Priority (TCP-LP), a distributed algorithm whose goal is
518 to utilize only the excess network bandwidth as compared to the
519 ``fair share`` of bandwidth as targeted by TCP.
520 See http://www-ece.rice.edu/networks/TCP-LP/
521
522config TCP_CONG_VENO
523 tristate "TCP Veno"
524 default n
525 ---help---
526 TCP Veno is a sender-side only enhancement of TCP to obtain better
527 throughput over wireless networks. TCP Veno makes use of state
528 distinguishing to circumvent the difficult judgment of the packet loss
529 type. TCP Veno cuts down less congestion window in response to random
530 loss packets.
531 See <http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=1177186>
532
533config TCP_CONG_YEAH
534 tristate "YeAH TCP"
535 select TCP_CONG_VEGAS
536 default n
537 ---help---
538 YeAH-TCP is a sender-side high-speed enabled TCP congestion control
539 algorithm, which uses a mixed loss/delay approach to compute the
540 congestion window. It's design goals target high efficiency,
541 internal, RTT and Reno fairness, resilience to link loss while
542 keeping network elements load as low as possible.
543
544 For further details look here:
545 http://wil.cs.caltech.edu/pfldnet2007/paper/YeAH_TCP.pdf
546
547config TCP_CONG_ILLINOIS
548 tristate "TCP Illinois"
549 default n
550 ---help---
551 TCP-Illinois is a sender-side modification of TCP Reno for
552 high speed long delay links. It uses round-trip-time to
553 adjust the alpha and beta parameters to achieve a higher average
554 throughput and maintain fairness.
555
556 For further details see:
557 http://www.ews.uiuc.edu/~shaoliu/tcpillinois/index.html
558
559choice
560 prompt "Default TCP congestion control"
561 default DEFAULT_CUBIC
562 help
563 Select the TCP congestion control that will be used by default
564 for all connections.
565
566 config DEFAULT_BIC
567 bool "Bic" if TCP_CONG_BIC=y
568
569 config DEFAULT_CUBIC
570 bool "Cubic" if TCP_CONG_CUBIC=y
571
572 config DEFAULT_HTCP
573 bool "Htcp" if TCP_CONG_HTCP=y
574
575 config DEFAULT_HYBLA
576 bool "Hybla" if TCP_CONG_HYBLA=y
577
578 config DEFAULT_VEGAS
579 bool "Vegas" if TCP_CONG_VEGAS=y
580
581 config DEFAULT_VENO
582 bool "Veno" if TCP_CONG_VENO=y
583
584 config DEFAULT_WESTWOOD
585 bool "Westwood" if TCP_CONG_WESTWOOD=y
586
587 config DEFAULT_RENO
588 bool "Reno"
589
590endchoice
591
592endif
593
594config TCP_CONG_CUBIC
595 tristate
596 depends on !TCP_CONG_ADVANCED
597 default y
598
599config DEFAULT_TCP_CONG
600 string
601 default "bic" if DEFAULT_BIC
602 default "cubic" if DEFAULT_CUBIC
603 default "htcp" if DEFAULT_HTCP
604 default "hybla" if DEFAULT_HYBLA
605 default "vegas" if DEFAULT_VEGAS
606 default "westwood" if DEFAULT_WESTWOOD
607 default "veno" if DEFAULT_VENO
608 default "reno" if DEFAULT_RENO
609 default "cubic"
610
611config TCP_MD5SIG
612 bool "TCP: MD5 Signature Option support (RFC2385)"
613 select CRYPTO
614 select CRYPTO_MD5
615 ---help---
616 RFC2385 specifies a method of giving MD5 protection to TCP sessions.
617 Its main (only?) use is to protect BGP sessions between core routers
618 on the Internet.
619
620 If unsure, say N.
621
