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.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.
  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 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:
  47
  48           echo 1 > /proc/sys/net/ipv4/conf/<device>/rp_filter
  49            or
  50           echo 1 > /proc/sys/net/ipv4/conf/all/rp_filter
  51
  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>.
  55
  56           If unsure, say N here.
  57
  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
  62
  63 config ASK_IP_FIB_HASH
  64         bool "FIB_HASH"
  65         ---help---
  66           Current FIB is very proven and good enough for most users.
  67
  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.
  74
  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.
  78
  79           LC-trie is described in:
  80
  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
  84
  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.csc.kth.se/~snilsson/software/dyntrie2/>
  88
  89 endchoice
  90
  91 config IP_FIB_HASH
  92         def_bool ASK_IP_FIB_HASH || !IP_ADVANCED_ROUTER
  93
  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.
 100
 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.
 111
 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/>.
 117
 118           If unsure, say N.
 119
 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.
 131
 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").
 142
 143 config IP_ROUTE_CLASSID
 144         bool
 145
 146 config IP_PNP
 147         bool "IP: kernel level autoconfiguration"
 148         help
 149           This enables automatic configuration of IP addresses of devices and
 150           of the routing table during kernel boot, based on either information
 151           supplied on the kernel command line or by BOOTP or RARP protocols.
 152           You need to say Y only for diskless machines requiring network
 153           access to boot (in which case you want to say Y to "Root file system
 154           on NFS" as well), because all other machines configure the network
 155           in their startup scripts.
 156
 157 config IP_PNP_DHCP
 158         bool "IP: DHCP support"
 159         depends on IP_PNP
 160         ---help---
 161           If you want your Linux box to mount its whole root file system (the
 162           one containing the directory /) from some other computer over the
 163           net via NFS and you want the IP address of your computer to be
 164           discovered automatically at boot time using the DHCP protocol (a
 165           special protocol designed for doing this job), say Y here. In case
 166           the boot ROM of your network card was designed for booting Linux and
 167           does DHCP itself, providing all necessary information on the kernel
 168           command line, you can say N here.
 169
 170           If unsure, say Y. Note that if you want to use DHCP, a DHCP server
 171           must be operating on your network.  Read
 172           <file:Documentation/filesystems/nfs/nfsroot.txt> for details.
 173
 174 config IP_PNP_BOOTP
 175         bool "IP: BOOTP support"
 176         depends on IP_PNP
 177         ---help---
 178           If you want your Linux box to mount its whole root file system (the
 179           one containing the directory /) from some other computer over the
 180           net via NFS and you want the IP address of your computer to be
 181           discovered automatically at boot time using the BOOTP protocol (a
 182           special protocol designed for doing this job), say Y here. In case
 183           the boot ROM of your network card was designed for booting Linux and
 184           does BOOTP itself, providing all necessary information on the kernel
 185           command line, you can say N here. If unsure, say Y. Note that if you
 186           want to use BOOTP, a BOOTP server must be operating on your network.
 187           Read <file:Documentation/filesystems/nfs/nfsroot.txt> for details.
 188
 189 config IP_PNP_RARP
 190         bool "IP: RARP support"
 191         depends on IP_PNP
 192         help
 193           If you want your Linux box to mount its whole root file system (the
 194           one containing the directory /) from some other computer over the
 195           net via NFS and you want the IP address of your computer to be
 196           discovered automatically at boot time using the RARP protocol (an
 197           older protocol which is being obsoleted by BOOTP and DHCP), say Y
 198           here. Note that if you want to use RARP, a RARP server must be
 199           operating on your network. Read
 200           <file:Documentation/filesystems/nfs/nfsroot.txt> for details.
 201
 202 # not yet ready..
 203 #   bool '    IP: ARP support' CONFIG_IP_PNP_ARP
 204 config NET_IPIP
 205         tristate "IP: tunneling"
 206         select INET_TUNNEL
 207         ---help---
 208           Tunneling means encapsulating data of one protocol type within
 209           another protocol and sending it over a channel that understands the
 210           encapsulating protocol. This particular tunneling driver implements
 211           encapsulation of IP within IP, which sounds kind of pointless, but
 212           can be useful if you want to make your (or some other) machine
 213           appear on a different network than it physically is, or to use
 214           mobile-IP facilities (allowing laptops to seamlessly move between
 215           networks without changing their IP addresses).
 216
 217           Saying Y to this option will produce two modules ( = code which can
 218           be inserted in and removed from the running kernel whenever you
 219           want). Most people won't need this and can say N.
 220
 221 config NET_IPGRE_DEMUX
 222         tristate "IP: GRE demultiplexer"
 223         help
 224          This is helper module to demultiplex GRE packets on GRE version field criteria.
 225          Required by ip_gre and pptp modules.
 226
 227 config NET_IPGRE
 228         tristate "IP: GRE tunnels over IP"
 229         depends on (IPV6 || IPV6=n) && NET_IPGRE_DEMUX
 230         help
 231           Tunneling means encapsulating data of one protocol type within
 232           another protocol and sending it over a channel that understands the
 233           encapsulating protocol. This particular tunneling driver implements
 234           GRE (Generic Routing Encapsulation) and at this time allows
 235           encapsulating of IPv4 or IPv6 over existing IPv4 infrastructure.
 236           This driver is useful if the other endpoint is a Cisco router: Cisco
 237           likes GRE much better than the other Linux tunneling driver ("IP
 238           tunneling" above). In addition, GRE allows multicast redistribution
 239           through the tunnel.
 240
 241 config NET_IPGRE_BROADCAST
 242         bool "IP: broadcast GRE over IP"
 243         depends on IP_MULTICAST && NET_IPGRE
 244         help
 245           One application of GRE/IP is to construct a broadcast WAN (Wide Area
 246           Network), which looks like a normal Ethernet LAN (Local Area
 247           Network), but can be distributed all over the Internet. If you want
 248           to do that, say Y here and to "IP multicast routing" below.
 249
 250 config IP_MROUTE
 251         bool "IP: multicast routing"
 252         depends on IP_MULTICAST
 253         help
 254           This is used if you want your machine to act as a router for IP
 255           packets that have several destination addresses. It is needed on the
 256           MBONE, a high bandwidth network on top of the Internet which carries
 257           audio and video broadcasts. In order to do that, you would most
 258           likely run the program mrouted. Information about the multicast
 259           capabilities of the various network cards is contained in
 260           <file:Documentation/networking/multicast.txt>. If you haven't heard
 261           about it, you don't need it.
 262
 263 config IP_MROUTE_MULTIPLE_TABLES
 264         bool "IP: multicast policy routing"
 265         depends on IP_MROUTE && IP_ADVANCED_ROUTER
 266         select FIB_RULES
 267         help
 268           Normally, a multicast router runs a userspace daemon and decides
 269           what to do with a multicast packet based on the source and
 270           destination addresses. If you say Y here, the multicast router
 271           will also be able to take interfaces and packet marks into
 272           account and run multiple instances of userspace daemons
 273           simultaneously, each one handling a single table.
 274
 275           If unsure, say N.
 276
 277 config IP_PIMSM_V1
 278         bool "IP: PIM-SM version 1 support"
 279         depends on IP_MROUTE
 280         help
 281           Kernel side support for Sparse Mode PIM (Protocol Independent
 282           Multicast) version 1. This multicast routing protocol is used widely
 283           because Cisco supports it. You need special software to use it
 284           (pimd-v1). Please see <http://netweb.usc.edu/pim/> for more
 285           information about PIM.
 286
 287           Say Y if you want to use PIM-SM v1. Note that you can say N here if
 288           you just want to use Dense Mode PIM.
 289
 290 config IP_PIMSM_V2
 291         bool "IP: PIM-SM version 2 support"
 292         depends on IP_MROUTE
 293         help
 294           Kernel side support for Sparse Mode PIM version 2. In order to use
 295           this, you need an experimental routing daemon supporting it (pimd or
 296           gated-5). This routing protocol is not used widely, so say N unless
 297           you want to play with it.
 298
 299 config ARPD
 300         bool "IP: ARP daemon support"
 301         ---help---
 302           The kernel maintains an internal cache which maps IP addresses to
 303           hardware addresses on the local network, so that Ethernet/Token Ring/
 304           etc. frames are sent to the proper address on the physical networking
 305           layer. Normally, kernel uses the ARP protocol to resolve these
 306           mappings.
 307
 308           Saying Y here adds support to have an user space daemon to do this
 309           resolution instead. This is useful for implementing an alternate
 310           address resolution protocol (e.g. NHRP on mGRE tunnels) and also for
 311           testing purposes.
 312
 313           If unsure, say N.
 314
 315 config SYN_COOKIES
 316         bool "IP: TCP syncookie support"
 317         ---help---
 318           Normal TCP/IP networking is open to an attack known as "SYN
 319           flooding". This denial-of-service attack prevents legitimate remote
 320           users from being able to connect to your computer during an ongoing
 321           attack and requires very little work from the attacker, who can
 322           operate from anywhere on the Internet.
 323
 324           SYN cookies provide protection against this type of attack. If you
 325           say Y here, the TCP/IP stack will use a cryptographic challenge
 326           protocol known as "SYN cookies" to enable legitimate users to
 327           continue to connect, even when your machine is under attack. There
 328           is no need for the legitimate users to change their TCP/IP software;
 329           SYN cookies work transparently to them. For technical information
 330           about SYN cookies, check out <http://cr.yp.to/syncookies.html>.
 331
 332           If you are SYN flooded, the source address reported by the kernel is
 333           likely to have been forged by the attacker; it is only reported as
 334           an aid in tracing the packets to their actual source and should not
 335           be taken as absolute truth.
 336
 337           SYN cookies may prevent correct error reporting on clients when the
 338           server is really overloaded. If this happens frequently better turn
 339           them off.
 340
 341           If you say Y here, you can disable SYN cookies at run time by
 342           saying Y to "/proc file system support" and
 343           "Sysctl support" below and executing the command
 344
 345           echo 0 > /proc/sys/net/ipv4/tcp_syncookies
 346
 347           after the /proc file system has been mounted.
 348
 349           If unsure, say N.
 350
 351 config INET_AH
 352         tristate "IP: AH transformation"
 353         select XFRM
 354         select CRYPTO
 355         select CRYPTO_HMAC
 356         select CRYPTO_MD5
 357         select CRYPTO_SHA1
 358         ---help---
 359           Support for IPsec AH.
 360
 361           If unsure, say Y.
 362
 363 config INET_ESP
 364         tristate "IP: ESP transformation"
 365         select XFRM
 366         select CRYPTO
 367         select CRYPTO_AUTHENC
 368         select CRYPTO_HMAC
 369         select CRYPTO_MD5
 370         select CRYPTO_CBC
 371         select CRYPTO_SHA1
 372         select CRYPTO_DES
 373         ---help---
 374           Support for IPsec ESP.
 375
 376           If unsure, say Y.
 377
 378 config INET_IPCOMP
 379         tristate "IP: IPComp transformation"
 380         select INET_XFRM_TUNNEL
 381         select XFRM_IPCOMP
 382         ---help---
 383           Support for IP Payload Compression Protocol (IPComp) (RFC3173),
 384           typically needed for IPsec.
 385
 386           If unsure, say Y.
 387
 388 config INET_XFRM_TUNNEL
 389         tristate
 390         select INET_TUNNEL
 391         default n
 392
 393 config INET_TUNNEL
 394         tristate
 395         default n
 396
 397 config INET_XFRM_MODE_TRANSPORT
 398         tristate "IP: IPsec transport mode"
 399         default y
 400         select XFRM
 401         ---help---
 402           Support for IPsec transport mode.
 403
 404           If unsure, say Y.
 405
 406 config INET_XFRM_MODE_TUNNEL
 407         tristate "IP: IPsec tunnel mode"
 408         default y
 409         select XFRM
 410         ---help---
 411           Support for IPsec tunnel mode.
 412
 413           If unsure, say Y.
 414
 415 config INET_XFRM_MODE_BEET
 416         tristate "IP: IPsec BEET mode"
 417         default y
 418         select XFRM
 419         ---help---
 420           Support for IPsec BEET mode.
 421
 422           If unsure, say Y.
 423
 424 config INET_LRO
 425         tristate "Large Receive Offload (ipv4/tcp)"
 426         default y
 427         ---help---
 428           Support for Large Receive Offload (ipv4/tcp).
 429
 430           If unsure, say Y.
 431
 432 config INET_DIAG
 433         tristate "INET: socket monitoring interface"
 434         default y
 435         ---help---
 436           Support for INET (TCP, DCCP, etc) socket monitoring interface used by
 437           native Linux tools such as ss. ss is included in iproute2, currently
 438           downloadable at:
 439
 440             http://www.linuxfoundation.org/collaborate/workgroups/networking/iproute2
 441
 442           If unsure, say Y.
 443
 444 config INET_TCP_DIAG
 445         depends on INET_DIAG
 446         def_tristate INET_DIAG
 447
 448 menuconfig TCP_CONG_ADVANCED
 449         bool "TCP: advanced congestion control"
 450         ---help---
 451           Support for selection of various TCP congestion control
 452           modules.
 453
 454           Nearly all users can safely say no here, and a safe default
 455           selection will be made (CUBIC with new Reno as a fallback).
 456
 457           If unsure, say N.
 458
 459 if TCP_CONG_ADVANCED
 460
 461 config TCP_CONG_BIC
 462         tristate "Binary Increase Congestion (BIC) control"
 463         default m
 464         ---help---
 465         BIC-TCP is a sender-side only change that ensures a linear RTT
 466         fairness under large windows while offering both scalability and
 467         bounded TCP-friendliness. The protocol combines two schemes
 468         called additive increase and binary search increase. When the
 469         congestion window is large, additive increase with a large
 470         increment ensures linear RTT fairness as well as good
 471         scalability. Under small congestion windows, binary search
 472         increase provides TCP friendliness.
 473         See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/
 474
 475 config TCP_CONG_CUBIC
 476         tristate "CUBIC TCP"
 477         default y
 478         ---help---
 479         This is version 2.0 of BIC-TCP which uses a cubic growth function
 480         among other techniques.
 481         See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/cubic-paper.pdf
 482
 483 config TCP_CONG_WESTWOOD
 484         tristate "TCP Westwood+"
 485         default m
 486         ---help---
 487         TCP Westwood+ is a sender-side only modification of the TCP Reno
 488         protocol stack that optimizes the performance of TCP congestion
 489         control. It is based on end-to-end bandwidth estimation to set
 490         congestion window and slow start threshold after a congestion
 491         episode. Using this estimation, TCP Westwood+ adaptively sets a
 492         slow start threshold and a congestion window which takes into
 493         account the bandwidth used  at the time congestion is experienced.
 494         TCP Westwood+ significantly increases fairness wrt TCP Reno in
 495         wired networks and throughput over wireless links.
 496
 497 config TCP_CONG_HTCP
 498         tristate "H-TCP"
 499         default m
 500         ---help---
 501         H-TCP is a send-side only modifications of the TCP Reno
 502         protocol stack that optimizes the performance of TCP
 503         congestion control for high speed network links. It uses a
 504         modeswitch to change the alpha and beta parameters of TCP Reno
 505         based on network conditions and in a way so as to be fair with
 506         other Reno and H-TCP flows.
 507
 508 config TCP_CONG_HSTCP
 509         tristate "High Speed TCP"
 510         depends on EXPERIMENTAL
 511         default n
 512         ---help---
 513         Sally Floyd's High Speed TCP (RFC 3649) congestion control.
 514         A modification to TCP's congestion control mechanism for use
 515         with large congestion windows. A table indicates how much to
 516         increase the congestion window by when an ACK is received.
 517         For more detail see http://www.icir.org/floyd/hstcp.html
 518
 519 config TCP_CONG_HYBLA
 520         tristate "TCP-Hybla congestion control algorithm"
 521         depends on EXPERIMENTAL
 522         default n
 523         ---help---
 524         TCP-Hybla is a sender-side only change that eliminates penalization of
 525         long-RTT, large-bandwidth connections, like when satellite legs are
 526         involved, especially when sharing a common bottleneck with normal
 527         terrestrial connections.
 528
 529 config TCP_CONG_VEGAS
 530         tristate "TCP Vegas"
 531         depends on EXPERIMENTAL
 532         default n
 533         ---help---
 534         TCP Vegas is a sender-side only change to TCP that anticipates
 535         the onset of congestion by estimating the bandwidth. TCP Vegas
 536         adjusts the sending rate by modifying the congestion
 537         window. TCP Vegas should provide less packet loss, but it is
 538         not as aggressive as TCP Reno.
 539
 540 config TCP_CONG_SCALABLE
 541         tristate "Scalable TCP"
 542         depends on EXPERIMENTAL
 543         default n
 544         ---help---
 545         Scalable TCP is a sender-side only change to TCP which uses a
 546         MIMD congestion control algorithm which has some nice scaling
 547         properties, though is known to have fairness issues.
 548         See http://www.deneholme.net/tom/scalable/
 549
 550 config TCP_CONG_LP
 551         tristate "TCP Low Priority"
 552         depends on EXPERIMENTAL
 553         default n
 554         ---help---
 555         TCP Low Priority (TCP-LP), a distributed algorithm whose goal is
 556         to utilize only the excess network bandwidth as compared to the
 557         ``fair share`` of bandwidth as targeted by TCP.
 558         See http://www-ece.rice.edu/networks/TCP-LP/
 559
 560 config TCP_CONG_VENO
 561         tristate "TCP Veno"
 562         depends on EXPERIMENTAL
 563         default n
 564         ---help---
 565         TCP Veno is a sender-side only enhancement of TCP to obtain better
 566         throughput over wireless networks. TCP Veno makes use of state
 567         distinguishing to circumvent the difficult judgment of the packet loss
 568         type. TCP Veno cuts down less congestion window in response to random
 569         loss packets.
 570         See <http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=1177186>
 571
 572 config TCP_CONG_YEAH
 573         tristate "YeAH TCP"
 574         depends on EXPERIMENTAL
 575         select TCP_CONG_VEGAS
 576         default n
 577         ---help---
 578         YeAH-TCP is a sender-side high-speed enabled TCP congestion control
 579         algorithm, which uses a mixed loss/delay approach to compute the
 580         congestion window. It's design goals target high efficiency,
 581         internal, RTT and Reno fairness, resilience to link loss while
 582         keeping network elements load as low as possible.
 583
 584         For further details look here:
 585           http://wil.cs.caltech.edu/pfldnet2007/paper/YeAH_TCP.pdf
 586
 587 config TCP_CONG_ILLINOIS
 588         tristate "TCP Illinois"
 589         depends on EXPERIMENTAL
 590         default n
 591         ---help---
 592         TCP-Illinois is a sender-side modification of TCP Reno for
 593         high speed long delay links. It uses round-trip-time to
 594         adjust the alpha and beta parameters to achieve a higher average
 595         throughput and maintain fairness.
 596
 597         For further details see:
 598           http://www.ews.uiuc.edu/~shaoliu/tcpillinois/index.html
 599
 600 choice
 601         prompt "Default TCP congestion control"
 602         default DEFAULT_CUBIC
 603         help
 604           Select the TCP congestion control that will be used by default
 605           for all connections.
 606
 607         config DEFAULT_BIC
 608                 bool "Bic" if TCP_CONG_BIC=y
 609
 610         config DEFAULT_CUBIC
 611                 bool "Cubic" if TCP_CONG_CUBIC=y
 612
 613         config DEFAULT_HTCP
 614                 bool "Htcp" if TCP_CONG_HTCP=y
 615
 616         config DEFAULT_HYBLA
 617                 bool "Hybla" if TCP_CONG_HYBLA=y
 618
 619         config DEFAULT_VEGAS
 620                 bool "Vegas" if TCP_CONG_VEGAS=y
 621
 622         config DEFAULT_VENO
 623                 bool "Veno" if TCP_CONG_VENO=y
 624
 625         config DEFAULT_WESTWOOD
 626                 bool "Westwood" if TCP_CONG_WESTWOOD=y
 627
 628         config DEFAULT_RENO
 629                 bool "Reno"
 630
 631 endchoice
 632
 633 endif
 634
 635 config TCP_CONG_CUBIC
 636         tristate
 637         depends on !TCP_CONG_ADVANCED
 638         default y
 639
 640 config DEFAULT_TCP_CONG
 641         string
 642         default "bic" if DEFAULT_BIC
 643         default "cubic" if DEFAULT_CUBIC
 644         default "htcp" if DEFAULT_HTCP
 645         default "hybla" if DEFAULT_HYBLA
 646         default "vegas" if DEFAULT_VEGAS
 647         default "westwood" if DEFAULT_WESTWOOD
 648         default "veno" if DEFAULT_VENO
 649         default "reno" if DEFAULT_RENO
 650         default "cubic"
 651
 652 config TCP_MD5SIG
 653         bool "TCP: MD5 Signature Option support (RFC2385) (EXPERIMENTAL)"
 654         depends on EXPERIMENTAL
 655         select CRYPTO
 656         select CRYPTO_MD5
 657         ---help---
 658           RFC2385 specifies a method of giving MD5 protection to TCP sessions.
 659           Its main (only?) use is to protect BGP sessions between core routers
 660           on the Internet.
 661
 662           If unsure, say N.