net/ipv4/Kconfig

   1 #
   2 # IP configuration
   3 #
   4 config IP_MULTICAST
   5         bool "IP: multicasting"
   6         help
   7           This is code for addressing several networked computers at once,
   8           enlarging your kernel by about 2 KB. You need multicasting if you
   9           intend to participate in the MBONE, a high bandwidth network on top
  10           of the Internet which carries audio and video broadcasts. More
  11           information about the MBONE is on the WWW at
  12           <http://www-itg.lbl.gov/mbone/>. Information about the multicast
  13           capabilities of the various network cards is contained in
  14           <file:Documentation/networking/multicast.txt>. For most people, it's
  15           safe to say N.
  16
  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.
  24
  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.
  28
  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
  33
  34           echo "1" > /proc/sys/net/ipv4/ip_forward
  35
  36           at boot time after the /proc file system has been mounted.
  37
  38           If you turn on IP forwarding, you will also get the rp_filter, which
  39           automatically rejects incoming packets if the routing table entry
  40           for their source address doesn't match the network interface they're
  41           arriving on. This has security advantages because it prevents the
  42           so-called IP spoofing, however it can pose problems if you use
  43           asymmetric routing (packets from you to a host take a different path
  44           than packets from that host to you) or if you operate a non-routing
  45           host which has several IP addresses on different interfaces. To turn
  46           rp_filter off use:
  47
  48           echo 0 > /proc/sys/net/ipv4/conf/<device>/rp_filter
  49           or
  50           echo 0 > /proc/sys/net/ipv4/conf/all/rp_filter
  51
  52           If unsure, say N here.
  53
  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
  58
  59 config ASK_IP_FIB_HASH
  60         bool "FIB_HASH"
  61         ---help---
  62         Current FIB is very proven and good enough for most users.
  63
  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.
  70
  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.
  74
  75         LC-trie is described in:
  76
  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/
  82
  83 endchoice
  84
  85 config IP_FIB_HASH
  86         def_bool ASK_IP_FIB_HASH || !IP_ADVANCED_ROUTER
  87
  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.
  98
  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/>.
 104
 105           If unsure, say N.
 106
 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.
 118
 119 config IP_ROUTE_MULTIPATH_CACHED
 120         bool "IP: equal cost multipath with caching support (EXPERIMENTAL)"
 121         depends on IP_ROUTE_MULTIPATH
 122         help
 123           Normally, equal cost multipath routing is not supported by the
 124           routing cache. If you say Y here, alternative routes are cached
 125           and on cache lookup a route is chosen in a configurable fashion.
 126
 127           If unsure, say N.
 128
 129 config IP_ROUTE_MULTIPATH_RR
 130         tristate "MULTIPATH: round robin algorithm"
 131         depends on IP_ROUTE_MULTIPATH_CACHED
 132         help
 133           Mulitpath routes are chosen according to Round Robin
 134
 135 config IP_ROUTE_MULTIPATH_RANDOM
 136         tristate "MULTIPATH: random algorithm"
 137         depends on IP_ROUTE_MULTIPATH_CACHED
 138         help
 139           Multipath routes are chosen in a random fashion. Actually,
 140           there is no weight for a route. The advantage of this policy
 141           is that it is implemented stateless and therefore introduces only
 142           a very small delay.
 143
 144 config IP_ROUTE_MULTIPATH_WRANDOM
 145         tristate "MULTIPATH: weighted random algorithm"
 146         depends on IP_ROUTE_MULTIPATH_CACHED
 147         help
 148           Multipath routes are chosen in a weighted random fashion.
 149           The per route weights are the weights visible via ip route 2. As the
 150           corresponding state management introduces some overhead routing delay
 151           is increased.
 152
 153 config IP_ROUTE_MULTIPATH_DRR
 154         tristate "MULTIPATH: interface round robin algorithm"
 155         depends on IP_ROUTE_MULTIPATH_CACHED
 156         help
 157           Connections are distributed in a round robin fashion over the
 158           available interfaces. This policy makes sense if the connections
 159           should be primarily distributed on interfaces and not on routes.
 160
 161 config IP_ROUTE_VERBOSE
 162         bool "IP: verbose route monitoring"
 163         depends on IP_ADVANCED_ROUTER
 164         help
 165           If you say Y here, which is recommended, then the kernel will print
 166           verbose messages regarding the routing, for example warnings about
 167           received packets which look strange and could be evidence of an
 168           attack or a misconfigured system somewhere. The information is
 169           handled by the klogd daemon which is responsible for kernel messages
 170           ("man klogd").
 171
 172 config IP_PNP
 173         bool "IP: kernel level autoconfiguration"
 174         help
 175           This enables automatic configuration of IP addresses of devices and
 176           of the routing table during kernel boot, based on either information
 177           supplied on the kernel command line or by BOOTP or RARP protocols.
 178           You need to say Y only for diskless machines requiring network
 179           access to boot (in which case you want to say Y to "Root file system
 180           on NFS" as well), because all other machines configure the network
 181           in their startup scripts.
 182
 183 config IP_PNP_DHCP
 184         bool "IP: DHCP support"
 185         depends on IP_PNP
 186         ---help---
 187           If you want your Linux box to mount its whole root file system (the
 188           one containing the directory /) from some other computer over the
 189           net via NFS and you want the IP address of your computer to be
 190           discovered automatically at boot time using the DHCP protocol (a
 191           special protocol designed for doing this job), say Y here. In case
 192           the boot ROM of your network card was designed for booting Linux and
 193           does DHCP itself, providing all necessary information on the kernel
 194           command line, you can say N here.
 195
 196           If unsure, say Y. Note that if you want to use DHCP, a DHCP server
 197           must be operating on your network.  Read
 198           <file:Documentation/nfsroot.txt> for details.
 199
 200 config IP_PNP_BOOTP
 201         bool "IP: BOOTP support"
 202         depends on IP_PNP
 203         ---help---
 204           If you want your Linux box to mount its whole root file system (the
 205           one containing the directory /) from some other computer over the
 206           net via NFS and you want the IP address of your computer to be
 207           discovered automatically at boot time using the BOOTP protocol (a
 208           special protocol designed for doing this job), say Y here. In case
 209           the boot ROM of your network card was designed for booting Linux and
 210           does BOOTP itself, providing all necessary information on the kernel
 211           command line, you can say N here. If unsure, say Y. Note that if you
 212           want to use BOOTP, a BOOTP server must be operating on your network.
 213           Read <file:Documentation/nfsroot.txt> for details.
 214
 215 config IP_PNP_RARP
 216         bool "IP: RARP support"
 217         depends on IP_PNP
 218         help
 219           If you want your Linux box to mount its whole root file system (the
 220           one containing the directory /) from some other computer over the
 221           net via NFS and you want the IP address of your computer to be
 222           discovered automatically at boot time using the RARP protocol (an
 223           older protocol which is being obsoleted by BOOTP and DHCP), say Y
 224           here. Note that if you want to use RARP, a RARP server must be
 225           operating on your network. Read <file:Documentation/nfsroot.txt> for
 226           details.
 227
 228 # not yet ready..
 229 #   bool '    IP: ARP support' CONFIG_IP_PNP_ARP
 230 config NET_IPIP
 231         tristate "IP: tunneling"
 232         select INET_TUNNEL
 233         ---help---
 234           Tunneling means encapsulating data of one protocol type within
 235           another protocol and sending it over a channel that understands the
 236           encapsulating protocol. This particular tunneling driver implements
 237           encapsulation of IP within IP, which sounds kind of pointless, but
 238           can be useful if you want to make your (or some other) machine
 239           appear on a different network than it physically is, or to use
 240           mobile-IP facilities (allowing laptops to seamlessly move between
 241           networks without changing their IP addresses).
 242
 243           Saying Y to this option will produce two modules ( = code which can
 244           be inserted in and removed from the running kernel whenever you
 245           want). Most people won't need this and can say N.
 246
 247 config NET_IPGRE
 248         tristate "IP: GRE tunnels over IP"
 249         help
 250           Tunneling means encapsulating data of one protocol type within
 251           another protocol and sending it over a channel that understands the
 252           encapsulating protocol. This particular tunneling driver implements
 253           GRE (Generic Routing Encapsulation) and at this time allows
 254           encapsulating of IPv4 or IPv6 over existing IPv4 infrastructure.
 255           This driver is useful if the other endpoint is a Cisco router: Cisco
 256           likes GRE much better than the other Linux tunneling driver ("IP
 257           tunneling" above). In addition, GRE allows multicast redistribution
 258           through the tunnel.
 259
 260 config NET_IPGRE_BROADCAST
 261         bool "IP: broadcast GRE over IP"
 262         depends on IP_MULTICAST && NET_IPGRE
 263         help
 264           One application of GRE/IP is to construct a broadcast WAN (Wide Area
 265           Network), which looks like a normal Ethernet LAN (Local Area
 266           Network), but can be distributed all over the Internet. If you want
 267           to do that, say Y here and to "IP multicast routing" below.
 268
 269 config IP_MROUTE
 270         bool "IP: multicast routing"
 271         depends on IP_MULTICAST
 272         help
 273           This is used if you want your machine to act as a router for IP
 274           packets that have several destination addresses. It is needed on the
 275           MBONE, a high bandwidth network on top of the Internet which carries
 276           audio and video broadcasts. In order to do that, you would most
 277           likely run the program mrouted. Information about the multicast
 278           capabilities of the various network cards is contained in
 279           <file:Documentation/networking/multicast.txt>. If you haven't heard
 280           about it, you don't need it.
 281
 282 config IP_PIMSM_V1
 283         bool "IP: PIM-SM version 1 support"
 284         depends on IP_MROUTE
 285         help
 286           Kernel side support for Sparse Mode PIM (Protocol Independent
 287           Multicast) version 1. This multicast routing protocol is used widely
 288           because Cisco supports it. You need special software to use it
 289           (pimd-v1). Please see <http://netweb.usc.edu/pim/> for more
 290           information about PIM.
 291
 292           Say Y if you want to use PIM-SM v1. Note that you can say N here if
 293           you just want to use Dense Mode PIM.
 294
 295 config IP_PIMSM_V2
 296         bool "IP: PIM-SM version 2 support"
 297         depends on IP_MROUTE
 298         help
 299           Kernel side support for Sparse Mode PIM version 2. In order to use
 300           this, you need an experimental routing daemon supporting it (pimd or
 301           gated-5). This routing protocol is not used widely, so say N unless
 302           you want to play with it.
 303
 304 config ARPD
 305         bool "IP: ARP daemon support (EXPERIMENTAL)"
 306         depends on EXPERIMENTAL
 307         ---help---
 308           Normally, the kernel maintains an internal cache which maps IP
 309           addresses to hardware addresses on the local network, so that
 310           Ethernet/Token Ring/ etc. frames are sent to the proper address on
 311           the physical networking layer. For small networks having a few
 312           hundred directly connected hosts or less, keeping this address
 313           resolution (ARP) cache inside the kernel works well. However,
 314           maintaining an internal ARP cache does not work well for very large
 315           switched networks, and will use a lot of kernel memory if TCP/IP
 316           connections are made to many machines on the network.
 317
 318           If you say Y here, the kernel's internal ARP cache will never grow
 319           to more than 256 entries (the oldest entries are expired in a LIFO
 320           manner) and communication will be attempted with the user space ARP
 321           daemon arpd. Arpd then answers the address resolution request either
 322           from its own cache or by asking the net.
 323
 324           This code is experimental and also obsolete. If you want to use it,
 325           you need to find a version of the daemon arpd on the net somewhere,
 326           and you should also say Y to "Kernel/User network link driver",
 327           below. If unsure, say N.
 328
 329 config SYN_COOKIES
 330         bool "IP: TCP syncookie support (disabled per default)"
 331         ---help---
 332           Normal TCP/IP networking is open to an attack known as "SYN
 333           flooding". This denial-of-service attack prevents legitimate remote
 334           users from being able to connect to your computer during an ongoing
 335           attack and requires very little work from the attacker, who can
 336           operate from anywhere on the Internet.
 337
 338           SYN cookies provide protection against this type of attack. If you
 339           say Y here, the TCP/IP stack will use a cryptographic challenge
 340           protocol known as "SYN cookies" to enable legitimate users to
 341           continue to connect, even when your machine is under attack. There
 342           is no need for the legitimate users to change their TCP/IP software;
 343           SYN cookies work transparently to them. For technical information
 344           about SYN cookies, check out <http://cr.yp.to/syncookies.html>.
 345
 346           If you are SYN flooded, the source address reported by the kernel is
 347           likely to have been forged by the attacker; it is only reported as
 348           an aid in tracing the packets to their actual source and should not
 349           be taken as absolute truth.
 350
 351           SYN cookies may prevent correct error reporting on clients when the
 352           server is really overloaded. If this happens frequently better turn
 353           them off.
 354
 355           If you say Y here, note that SYN cookies aren't enabled by default;
 356           you can enable them by saying Y to "/proc file system support" and
 357           "Sysctl support" below and executing the command
 358
 359           echo 1 >/proc/sys/net/ipv4/tcp_syncookies
 360
 361           at boot time after the /proc file system has been mounted.
 362
 363           If unsure, say N.
 364
 365 config INET_AH
 366         tristate "IP: AH transformation"
 367         select XFRM
 368         select CRYPTO
 369         select CRYPTO_HMAC
 370         select CRYPTO_MD5
 371         select CRYPTO_SHA1
 372         ---help---
 373           Support for IPsec AH.
 374
 375           If unsure, say Y.
 376
 377 config INET_ESP
 378         tristate "IP: ESP transformation"
 379         select XFRM
 380         select CRYPTO
 381         select CRYPTO_HMAC
 382         select CRYPTO_MD5
 383         select CRYPTO_CBC
 384         select CRYPTO_SHA1
 385         select CRYPTO_DES
 386         ---help---
 387           Support for IPsec ESP.
 388
 389           If unsure, say Y.
 390
 391 config INET_IPCOMP
 392         tristate "IP: IPComp transformation"
 393         select XFRM
 394         select INET_XFRM_TUNNEL
 395         select CRYPTO
 396         select CRYPTO_DEFLATE
 397         ---help---
 398           Support for IP Payload Compression Protocol (IPComp) (RFC3173),
 399           typically needed for IPsec.
 400
 401           If unsure, say Y.
 402
 403 config INET_XFRM_TUNNEL
 404         tristate
 405         select INET_TUNNEL
 406         default n
 407
 408 config INET_TUNNEL
 409         tristate
 410         default n
 411
 412 config INET_XFRM_MODE_TRANSPORT
 413         tristate "IP: IPsec transport mode"
 414         default y
 415         select XFRM
 416         ---help---
 417           Support for IPsec transport mode.
 418
 419           If unsure, say Y.
 420
 421 config INET_XFRM_MODE_TUNNEL
 422         tristate "IP: IPsec tunnel mode"
 423         default y
 424         select XFRM
 425         ---help---
 426           Support for IPsec tunnel mode.
 427
 428           If unsure, say Y.
 429
 430 config INET_XFRM_MODE_BEET
 431         tristate "IP: IPsec BEET mode"
 432         default y
 433         select XFRM
 434         ---help---
 435           Support for IPsec BEET mode.
 436
 437           If unsure, say Y.
 438
 439 config INET_DIAG
 440         tristate "INET: socket monitoring interface"
 441         default y
 442         ---help---
 443           Support for INET (TCP, DCCP, etc) socket monitoring interface used by
 444           native Linux tools such as ss. ss is included in iproute2, currently
 445           downloadable at <http://developer.osdl.org/dev/iproute2>.
 446
 447           If unsure, say Y.
 448
 449 config INET_TCP_DIAG
 450         depends on INET_DIAG
 451         def_tristate INET_DIAG
 452
 453 menuconfig TCP_CONG_ADVANCED
 454         bool "TCP: advanced congestion control"
 455         ---help---
 456           Support for selection of various TCP congestion control
 457           modules.
 458
 459           Nearly all users can safely say no here, and a safe default
 460           selection will be made (CUBIC with new Reno as a fallback).
 461
 462           If unsure, say N.
 463
 464 if TCP_CONG_ADVANCED
 465
 466 config TCP_CONG_BIC
 467         tristate "Binary Increase Congestion (BIC) control"
 468         default m
 469         ---help---
 470         BIC-TCP is a sender-side only change that ensures a linear RTT
 471         fairness under large windows while offering both scalability and
 472         bounded TCP-friendliness. The protocol combines two schemes
 473         called additive increase and binary search increase. When the
 474         congestion window is large, additive increase with a large
 475         increment ensures linear RTT fairness as well as good
 476         scalability. Under small congestion windows, binary search
 477         increase provides TCP friendliness.
 478         See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/
 479
 480 config TCP_CONG_CUBIC
 481         tristate "CUBIC TCP"
 482         default y
 483         ---help---
 484         This is version 2.0 of BIC-TCP which uses a cubic growth function
 485         among other techniques.
 486         See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/cubic-paper.pdf
 487
 488 config TCP_CONG_WESTWOOD
 489         tristate "TCP Westwood+"
 490         default m
 491         ---help---
 492         TCP Westwood+ is a sender-side only modification of the TCP Reno
 493         protocol stack that optimizes the performance of TCP congestion
 494         control. It is based on end-to-end bandwidth estimation to set
 495         congestion window and slow start threshold after a congestion
 496         episode. Using this estimation, TCP Westwood+ adaptively sets a
 497         slow start threshold and a congestion window which takes into
 498         account the bandwidth used  at the time congestion is experienced.
 499         TCP Westwood+ significantly increases fairness wrt TCP Reno in
 500         wired networks and throughput over wireless links.
 501
 502 config TCP_CONG_HTCP
 503         tristate "H-TCP"
 504         default m
 505         ---help---
 506         H-TCP is a send-side only modifications of the TCP Reno
 507         protocol stack that optimizes the performance of TCP
 508         congestion control for high speed network links. It uses a
 509         modeswitch to change the alpha and beta parameters of TCP Reno
 510         based on network conditions and in a way so as to be fair with
 511         other Reno and H-TCP flows.
 512
 513 config TCP_CONG_HSTCP
 514         tristate "High Speed TCP"
 515         depends on EXPERIMENTAL
 516         default n
 517         ---help---
 518         Sally Floyd's High Speed TCP (RFC 3649) congestion control.
 519         A modification to TCP's congestion control mechanism for use
 520         with large congestion windows. A table indicates how much to
 521         increase the congestion window by when an ACK is received.
 522         For more detail see http://www.icir.org/floyd/hstcp.html
 523
 524 config TCP_CONG_HYBLA
 525         tristate "TCP-Hybla congestion control algorithm"
 526         depends on EXPERIMENTAL
 527         default n
 528         ---help---
 529         TCP-Hybla is a sender-side only change that eliminates penalization of
 530         long-RTT, large-bandwidth connections, like when satellite legs are
 531         involved, especially when sharing a common bottleneck with normal
 532         terrestrial connections.
 533
 534 config TCP_CONG_VEGAS
 535         tristate "TCP Vegas"
 536         depends on EXPERIMENTAL
 537         default n
 538         ---help---
 539         TCP Vegas is a sender-side only change to TCP that anticipates
 540         the onset of congestion by estimating the bandwidth. TCP Vegas
 541         adjusts the sending rate by modifying the congestion
 542         window. TCP Vegas should provide less packet loss, but it is
 543         not as aggressive as TCP Reno.
 544
 545 config TCP_CONG_SCALABLE
 546         tristate "Scalable TCP"
 547         depends on EXPERIMENTAL
 548         default n
 549         ---help---
 550         Scalable TCP is a sender-side only change to TCP which uses a
 551         MIMD congestion control algorithm which has some nice scaling
 552         properties, though is known to have fairness issues.
 553         See http://www-lce.eng.cam.ac.uk/~ctk21/scalable/
 554
 555 config TCP_CONG_LP
 556         tristate "TCP Low Priority"
 557         depends on EXPERIMENTAL
 558         default n
 559         ---help---
 560         TCP Low Priority (TCP-LP), a distributed algorithm whose goal is
 561         to utilize only the excess network bandwidth as compared to the
 562         ``fair share`` of bandwidth as targeted by TCP.
 563         See http://www-ece.rice.edu/networks/TCP-LP/
 564
 565 config TCP_CONG_VENO
 566         tristate "TCP Veno"
 567         depends on EXPERIMENTAL
 568         default n
 569         ---help---
 570         TCP Veno is a sender-side only enhancement of TCP to obtain better
 571         throughput over wireless networks. TCP Veno makes use of state
 572         distinguishing to circumvent the difficult judgment of the packet loss
 573         type. TCP Veno cuts down less congestion window in response to random
 574         loss packets.
 575         See http://www.ntu.edu.sg/home5/ZHOU0022/papers/CPFu03a.pdf
 576
 577 choice
 578         prompt "Default TCP congestion control"
 579         default DEFAULT_CUBIC
 580         help
 581           Select the TCP congestion control that will be used by default
 582           for all connections.
 583
 584         config DEFAULT_BIC
 585                 bool "Bic" if TCP_CONG_BIC=y
 586
 587         config DEFAULT_CUBIC
 588                 bool "Cubic" if TCP_CONG_CUBIC=y
 589
 590         config DEFAULT_HTCP
 591                 bool "Htcp" if TCP_CONG_HTCP=y
 592
 593         config DEFAULT_VEGAS
 594                 bool "Vegas" if TCP_CONG_VEGAS=y
 595
 596         config DEFAULT_WESTWOOD
 597                 bool "Westwood" if TCP_CONG_WESTWOOD=y
 598
 599         config DEFAULT_RENO
 600                 bool "Reno"
 601
 602 endchoice
 603
 604 endif
 605
 606 config TCP_CONG_CUBIC
 607         tristate
 608         depends on !TCP_CONG_ADVANCED
 609         default y
 610
 611 config DEFAULT_TCP_CONG
 612         string
 613         default "bic" if DEFAULT_BIC
 614         default "cubic" if DEFAULT_CUBIC
 615         default "htcp" if DEFAULT_HTCP
 616         default "vegas" if DEFAULT_VEGAS
 617         default "westwood" if DEFAULT_WESTWOOD
 618         default "reno" if DEFAULT_RENO
 619         default "cubic"
 620
 621 config TCP_MD5SIG
 622         bool "TCP: MD5 Signature Option support (RFC2385) (EXPERIMENTAL)"
 623         depends on EXPERIMENTAL
 624         select CRYPTO
 625         select CRYPTO_MD5
 626         ---help---
 627           RFC2385 specifices a method of giving MD5 protection to TCP sessions.
 628           Its main (only?) use is to protect BGP sessions between core routers
 629           on the Internet.
 630
 631           If unsure, say N.
 632
 633 config TCP_MD5SIG_DEBUG
 634         bool "TCP: MD5 Signature Option debugging"
 635         depends on TCP_MD5SIG
 636
 637 source "net/ipv4/ipvs/Kconfig"
 638