Version:  2.0.40 2.2.26 2.4.37 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18


  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           <>. For most people, it's safe to say N.
 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.
 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.
 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
 31           echo "1" > /proc/sys/net/ipv4/ip_forward
 33           at boot time after the /proc file system has been mounted.
 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:
 45           echo 1 > /proc/sys/net/ipv4/conf/<device>/rp_filter
 46            or
 47           echo 1 > /proc/sys/net/ipv4/conf/all/rp_filter
 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>.
 53           If unsure, say N here.
 55 config 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.
 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.
 73           If you are interested in this, please see the preliminary
 74           documentation at <>
 75           and <>.
 76           You will need supporting software from
 77           <>.
 79           If unsure, say N.
 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.
 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").
105         bool
107 config 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.
118 config 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.
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.
135 config 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.
150 config 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.
163 config 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).
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.
181 config 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.
187 config NET_IP_TUNNEL
188         tristate
189         default n
191 config 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.
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.
215 config 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.
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.
238           If unsure, say N.
240 config 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 <> for more
248           information about PIM.
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.
253 config 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.
262 config 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.
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 <>.
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.
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.
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
292           echo 0 > /proc/sys/net/ipv4/tcp_syncookies
294           after the /proc file system has been mounted.
296           If unsure, say N.
298 config 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.
310 config NET_UDP_TUNNEL
311         tristate
312         select NET_IP_TUNNEL
313         default n
315 config NET_FOU
316         tristate "IP: Foo (IP protocols) over UDP"
317         select XFRM
318         select NET_UDP_TUNNEL
319         ---help---
320           Foo over UDP allows any IP protocol to be directly encapsulated
321           over UDP include tunnels (IPIP, GRE, SIT). By encapsulating in UDP
322           network mechanisms and optimizations for UDP (such as ECMP
323           and RSS) can be leveraged to provide better service.
325 config GENEVE
326         tristate "Generic Network Virtualization Encapsulation (Geneve)"
327         depends on INET
328         select NET_UDP_TUNNEL
329         ---help---
330         This allows one to create Geneve virtual interfaces that provide
331         Layer 2 Networks over Layer 3 Networks. Geneve is often used
332         to tunnel virtual network infrastructure in virtualized environments.
333         For more information see:
336           To compile this driver as a module, choose M here: the module
339 config INET_AH
340         tristate "IP: AH transformation"
341         select XFRM_ALGO
342         select CRYPTO
343         select CRYPTO_HMAC
344         select CRYPTO_MD5
345         select CRYPTO_SHA1
346         ---help---
347           Support for IPsec AH.
349           If unsure, say Y.
351 config INET_ESP
352         tristate "IP: ESP transformation"
353         select XFRM_ALGO
354         select CRYPTO
355         select CRYPTO_AUTHENC
356         select CRYPTO_HMAC
357         select CRYPTO_MD5
358         select CRYPTO_CBC
359         select CRYPTO_SHA1
360         select CRYPTO_DES
361         ---help---
362           Support for IPsec ESP.
364           If unsure, say Y.
366 config INET_IPCOMP
367         tristate "IP: IPComp transformation"
368         select INET_XFRM_TUNNEL
369         select XFRM_IPCOMP
370         ---help---
371           Support for IP Payload Compression Protocol (IPComp) (RFC3173),
372           typically needed for IPsec.
374           If unsure, say Y.
377         tristate
378         select INET_TUNNEL
379         default n
381 config INET_TUNNEL
382         tristate
383         default n
386         tristate "IP: IPsec transport mode"
387         default y
388         select XFRM
389         ---help---
390           Support for IPsec transport mode.
392           If unsure, say Y.
395         tristate "IP: IPsec tunnel mode"
396         default y
397         select XFRM
398         ---help---
399           Support for IPsec tunnel mode.
401           If unsure, say Y.
404         tristate "IP: IPsec BEET mode"
405         default y
406         select XFRM
407         ---help---
408           Support for IPsec BEET mode.
410           If unsure, say Y.
412 config INET_LRO
413         tristate "Large Receive Offload (ipv4/tcp)"
414         default y
415         ---help---
416           Support for Large Receive Offload (ipv4/tcp).
418           If unsure, say Y.
420 config INET_DIAG
421         tristate "INET: socket monitoring interface"
422         default y
423         ---help---
424           Support for INET (TCP, DCCP, etc) socket monitoring interface used by
425           native Linux tools such as ss. ss is included in iproute2, currently
426           downloadable at:
430           If unsure, say Y.
432 config INET_TCP_DIAG
433         depends on INET_DIAG
434         def_tristate INET_DIAG
436 config INET_UDP_DIAG
437         tristate "UDP: socket monitoring interface"
438         depends on INET_DIAG && (IPV6 || IPV6=n)
439         default n
440         ---help---
441           Support for UDP socket monitoring interface used by the ss tool.
442           If unsure, say Y.
444 menuconfig TCP_CONG_ADVANCED
445         bool "TCP: advanced congestion control"
446         ---help---
447           Support for selection of various TCP congestion control
448           modules.
450           Nearly all users can safely say no here, and a safe default
451           selection will be made (CUBIC with new Reno as a fallback).
453           If unsure, say N.
457 config TCP_CONG_BIC
458         tristate "Binary Increase Congestion (BIC) control"
459         default m
460         ---help---
461         BIC-TCP is a sender-side only change that ensures a linear RTT
462         fairness under large windows while offering both scalability and
463         bounded TCP-friendliness. The protocol combines two schemes
464         called additive increase and binary search increase. When the
465         congestion window is large, additive increase with a large
466         increment ensures linear RTT fairness as well as good
467         scalability. Under small congestion windows, binary search
468         increase provides TCP friendliness.
469         See
471 config TCP_CONG_CUBIC
472         tristate "CUBIC TCP"
473         default y
474         ---help---
475         This is version 2.0 of BIC-TCP which uses a cubic growth function
476         among other techniques.
477         See
480         tristate "TCP Westwood+"
481         default m
482         ---help---
483         TCP Westwood+ is a sender-side only modification of the TCP Reno
484         protocol stack that optimizes the performance of TCP congestion
485         control. It is based on end-to-end bandwidth estimation to set
486         congestion window and slow start threshold after a congestion
487         episode. Using this estimation, TCP Westwood+ adaptively sets a
488         slow start threshold and a congestion window which takes into
489         account the bandwidth used  at the time congestion is experienced.
490         TCP Westwood+ significantly increases fairness wrt TCP Reno in
491         wired networks and throughput over wireless links.
493 config TCP_CONG_HTCP
494         tristate "H-TCP"
495         default m
496         ---help---
497         H-TCP is a send-side only modifications of the TCP Reno
498         protocol stack that optimizes the performance of TCP
499         congestion control for high speed network links. It uses a
500         modeswitch to change the alpha and beta parameters of TCP Reno
501         based on network conditions and in a way so as to be fair with
502         other Reno and H-TCP flows.
504 config TCP_CONG_HSTCP
505         tristate "High Speed TCP"
506         default n
507         ---help---
508         Sally Floyd's High Speed TCP (RFC 3649) congestion control.
509         A modification to TCP's congestion control mechanism for use
510         with large congestion windows. A table indicates how much to
511         increase the congestion window by when an ACK is received.
512         For more detail see
514 config TCP_CONG_HYBLA
515         tristate "TCP-Hybla congestion control algorithm"
516         default n
517         ---help---
518         TCP-Hybla is a sender-side only change that eliminates penalization of
519         long-RTT, large-bandwidth connections, like when satellite legs are
520         involved, especially when sharing a common bottleneck with normal
521         terrestrial connections.
523 config TCP_CONG_VEGAS
524         tristate "TCP Vegas"
525         default n
526         ---help---
527         TCP Vegas is a sender-side only change to TCP that anticipates
528         the onset of congestion by estimating the bandwidth. TCP Vegas
529         adjusts the sending rate by modifying the congestion
530         window. TCP Vegas should provide less packet loss, but it is
531         not as aggressive as TCP Reno.
534         tristate "Scalable TCP"
535         default n
536         ---help---
537         Scalable TCP is a sender-side only change to TCP which uses a
538         MIMD congestion control algorithm which has some nice scaling
539         properties, though is known to have fairness issues.
540         See
542 config TCP_CONG_LP
543         tristate "TCP Low Priority"
544         default n
545         ---help---
546         TCP Low Priority (TCP-LP), a distributed algorithm whose goal is
547         to utilize only the excess network bandwidth as compared to the
548         ``fair share`` of bandwidth as targeted by TCP.
549         See
551 config TCP_CONG_VENO
552         tristate "TCP Veno"
553         default n
554         ---help---
555         TCP Veno is a sender-side only enhancement of TCP to obtain better
556         throughput over wireless networks. TCP Veno makes use of state
557         distinguishing to circumvent the difficult judgment of the packet loss
558         type. TCP Veno cuts down less congestion window in response to random
559         loss packets.
560         See <> 
562 config TCP_CONG_YEAH
563         tristate "YeAH TCP"
564         select TCP_CONG_VEGAS
565         default n
566         ---help---
567         YeAH-TCP is a sender-side high-speed enabled TCP congestion control
568         algorithm, which uses a mixed loss/delay approach to compute the
569         congestion window. It's design goals target high efficiency,
570         internal, RTT and Reno fairness, resilience to link loss while
571         keeping network elements load as low as possible.
573         For further details look here:
577         tristate "TCP Illinois"
578         default n
579         ---help---
580         TCP-Illinois is a sender-side modification of TCP Reno for
581         high speed long delay links. It uses round-trip-time to
582         adjust the alpha and beta parameters to achieve a higher average
583         throughput and maintain fairness.
585         For further details see:
588 config TCP_CONG_DCTCP
589         tristate "DataCenter TCP (DCTCP)"
590         default n
591         ---help---
592         DCTCP leverages Explicit Congestion Notification (ECN) in the network to
593         provide multi-bit feedback to the end hosts. It is designed to provide:
595         - High burst tolerance (incast due to partition/aggregate),
596         - Low latency (short flows, queries),
597         - High throughput (continuous data updates, large file transfers) with
598           commodity, shallow-buffered switches.
600         All switches in the data center network running DCTCP must support
601         ECN marking and be configured for marking when reaching defined switch
602         buffer thresholds. The default ECN marking threshold heuristic for
603         DCTCP on switches is 20 packets (30KB) at 1Gbps, and 65 packets
604         (~100KB) at 10Gbps, but might need further careful tweaking.
606         For further details see:
609 choice
610         prompt "Default TCP congestion control"
611         default DEFAULT_CUBIC
612         help
613           Select the TCP congestion control that will be used by default
614           for all connections.
616         config DEFAULT_BIC
617                 bool "Bic" if TCP_CONG_BIC=y
619         config DEFAULT_CUBIC
620                 bool "Cubic" if TCP_CONG_CUBIC=y
622         config DEFAULT_HTCP
623                 bool "Htcp" if TCP_CONG_HTCP=y
625         config DEFAULT_HYBLA
626                 bool "Hybla" if TCP_CONG_HYBLA=y
628         config DEFAULT_VEGAS
629                 bool "Vegas" if TCP_CONG_VEGAS=y
631         config DEFAULT_VENO
632                 bool "Veno" if TCP_CONG_VENO=y
634         config DEFAULT_WESTWOOD
635                 bool "Westwood" if TCP_CONG_WESTWOOD=y
637         config DEFAULT_DCTCP
638                 bool "DCTCP" if TCP_CONG_DCTCP=y
640         config DEFAULT_RENO
641                 bool "Reno"
642 endchoice
644 endif
646 config TCP_CONG_CUBIC
647         tristate
648         depends on !TCP_CONG_ADVANCED
649         default y
652         string
653         default "bic" if DEFAULT_BIC
654         default "cubic" if DEFAULT_CUBIC
655         default "htcp" if DEFAULT_HTCP
656         default "hybla" if DEFAULT_HYBLA
657         default "vegas" if DEFAULT_VEGAS
658         default "westwood" if DEFAULT_WESTWOOD
659         default "veno" if DEFAULT_VENO
660         default "reno" if DEFAULT_RENO
661         default "dctcp" if DEFAULT_DCTCP
662         default "cubic"
664 config TCP_MD5SIG
665         bool "TCP: MD5 Signature Option support (RFC2385)"
666         select CRYPTO
667         select CRYPTO_MD5
668         ---help---
669           RFC2385 specifies a method of giving MD5 protection to TCP sessions.
670           Its main (only?) use is to protect BGP sessions between core routers
671           on the Internet.
673           If unsure, say N.

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