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/>. For most people, it's safe to say N.
  13
  14 config 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
  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.
  61
  62 config 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 need more information, see the Linux Advanced
  74           Routing and Traffic Control documentation at
  75           <http://lartc.org/howto/lartc.rpdb.html>
  76
  77           If unsure, say N.
  78
  79 config IP_ROUTE_MULTIPATH
  80         bool "IP: equal cost multipath"
  81         depends on IP_ADVANCED_ROUTER
  82         help
  83           Normally, the routing tables specify a single action to be taken in
  84           a deterministic manner for a given packet. If you say Y here
  85           however, it becomes possible to attach several actions to a packet
  86           pattern, in effect specifying several alternative paths to travel
  87           for those packets. The router considers all these paths to be of
  88           equal "cost" and chooses one of them in a non-deterministic fashion
  89           if a matching packet arrives.
  90
  91 config IP_ROUTE_VERBOSE
  92         bool "IP: verbose route monitoring"
  93         depends on IP_ADVANCED_ROUTER
  94         help
  95           If you say Y here, which is recommended, then the kernel will print
  96           verbose messages regarding the routing, for example warnings about
  97           received packets which look strange and could be evidence of an
  98           attack or a misconfigured system somewhere. The information is
  99           handled by the klogd daemon which is responsible for kernel messages
 100           ("man klogd").
 101
 102 config IP_ROUTE_CLASSID
 103         bool
 104
 105 config IP_PNP
 106         bool "IP: kernel level autoconfiguration"
 107         help
 108           This enables automatic configuration of IP addresses of devices and
 109           of the routing table during kernel boot, based on either information
 110           supplied on the kernel command line or by BOOTP or RARP protocols.
 111           You need to say Y only for diskless machines requiring network
 112           access to boot (in which case you want to say Y to "Root file system
 113           on NFS" as well), because all other machines configure the network
 114           in their startup scripts.
 115
 116 config IP_PNP_DHCP
 117         bool "IP: DHCP support"
 118         depends on IP_PNP
 119         ---help---
 120           If you want your Linux box to mount its whole root file system (the
 121           one containing the directory /) from some other computer over the
 122           net via NFS and you want the IP address of your computer to be
 123           discovered automatically at boot time using the DHCP protocol (a
 124           special protocol designed for doing this job), say Y here. In case
 125           the boot ROM of your network card was designed for booting Linux and
 126           does DHCP itself, providing all necessary information on the kernel
 127           command line, you can say N here.
 128
 129           If unsure, say Y. Note that if you want to use DHCP, a DHCP server
 130           must be operating on your network.  Read
 131           <file:Documentation/filesystems/nfs/nfsroot.txt> for details.
 132
 133 config IP_PNP_BOOTP
 134         bool "IP: BOOTP support"
 135         depends on IP_PNP
 136         ---help---
 137           If you want your Linux box to mount its whole root file system (the
 138           one containing the directory /) from some other computer over the
 139           net via NFS and you want the IP address of your computer to be
 140           discovered automatically at boot time using the BOOTP protocol (a
 141           special protocol designed for doing this job), say Y here. In case
 142           the boot ROM of your network card was designed for booting Linux and
 143           does BOOTP itself, providing all necessary information on the kernel
 144           command line, you can say N here. If unsure, say Y. Note that if you
 145           want to use BOOTP, a BOOTP server must be operating on your network.
 146           Read <file:Documentation/filesystems/nfs/nfsroot.txt> for details.
 147
 148 config IP_PNP_RARP
 149         bool "IP: RARP support"
 150         depends on IP_PNP
 151         help
 152           If you want your Linux box to mount its whole root file system (the
 153           one containing the directory /) from some other computer over the
 154           net via NFS and you want the IP address of your computer to be
 155           discovered automatically at boot time using the RARP protocol (an
 156           older protocol which is being obsoleted by BOOTP and DHCP), say Y
 157           here. Note that if you want to use RARP, a RARP server must be
 158           operating on your network. Read
 159           <file:Documentation/filesystems/nfs/nfsroot.txt> for details.
 160
 161 config NET_IPIP
 162         tristate "IP: tunneling"
 163         select INET_TUNNEL
 164         select NET_IP_TUNNEL
 165         ---help---
 166           Tunneling means encapsulating data of one protocol type within
 167           another protocol and sending it over a channel that understands the
 168           encapsulating protocol. This particular tunneling driver implements
 169           encapsulation of IP within IP, which sounds kind of pointless, but
 170           can be useful if you want to make your (or some other) machine
 171           appear on a different network than it physically is, or to use
 172           mobile-IP facilities (allowing laptops to seamlessly move between
 173           networks without changing their IP addresses).
 174
 175           Saying Y to this option will produce two modules ( = code which can
 176           be inserted in and removed from the running kernel whenever you
 177           want). Most people won't need this and can say N.
 178
 179 config NET_IPGRE_DEMUX
 180         tristate "IP: GRE demultiplexer"
 181         help
 182          This is helper module to demultiplex GRE packets on GRE version field criteria.
 183          Required by ip_gre and pptp modules.
 184
 185 config NET_IP_TUNNEL
 186         tristate
 187         select DST_CACHE
 188         select GRO_CELLS
 189         default n
 190
 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.
 205
 206 config 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
 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.
 225
 226 config 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
 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 <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
 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.
 261
 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.
 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
 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.
 309
 310 config NET_UDP_TUNNEL
 311         tristate
 312         select NET_IP_TUNNEL
 313         default n
 314
 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.
 324
 325 config NET_FOU_IP_TUNNELS
 326         bool "IP: FOU encapsulation of IP tunnels"
 327         depends on NET_IPIP || NET_IPGRE || IPV6_SIT
 328         select NET_FOU
 329         ---help---
 330           Allow configuration of FOU or GUE encapsulation for IP tunnels.
 331           When this option is enabled IP tunnels can be configured to use
 332           FOU or GUE encapsulation.
 333
 334 config INET_AH
 335         tristate "IP: AH transformation"
 336         select XFRM_ALGO
 337         select CRYPTO
 338         select CRYPTO_HMAC
 339         select CRYPTO_MD5
 340         select CRYPTO_SHA1
 341         ---help---
 342           Support for IPsec AH.
 343
 344           If unsure, say Y.
 345
 346 config INET_ESP
 347         tristate "IP: ESP transformation"
 348         select XFRM_ALGO
 349         select CRYPTO
 350         select CRYPTO_AUTHENC
 351         select CRYPTO_HMAC
 352         select CRYPTO_MD5
 353         select CRYPTO_CBC
 354         select CRYPTO_SHA1
 355         select CRYPTO_DES
 356         select CRYPTO_ECHAINIV
 357         ---help---
 358           Support for IPsec ESP.
 359
 360           If unsure, say Y.
 361
 362 config INET_ESP_OFFLOAD
 363         tristate "IP: ESP transformation offload"
 364         depends on INET_ESP
 365         select XFRM_OFFLOAD
 366         default n
 367         ---help---
 368           Support for ESP transformation offload. This makes sense
 369           only if this system really does IPsec and want to do it
 370           with high throughput. A typical desktop system does not
 371           need it, even if it does IPsec.
 372
 373           If unsure, say N.
 374
 375 config INET_IPCOMP
 376         tristate "IP: IPComp transformation"
 377         select INET_XFRM_TUNNEL
 378         select XFRM_IPCOMP
 379         ---help---
 380           Support for IP Payload Compression Protocol (IPComp) (RFC3173),
 381           typically needed for IPsec.
 382
 383           If unsure, say Y.
 384
 385 config INET_XFRM_TUNNEL
 386         tristate
 387         select INET_TUNNEL
 388         default n
 389
 390 config INET_TUNNEL
 391         tristate
 392         default n
 393
 394 config INET_XFRM_MODE_TRANSPORT
 395         tristate "IP: IPsec transport mode"
 396         default y
 397         select XFRM
 398         ---help---
 399           Support for IPsec transport mode.
 400
 401           If unsure, say Y.
 402
 403 config INET_XFRM_MODE_TUNNEL
 404         tristate "IP: IPsec tunnel mode"
 405         default y
 406         select XFRM
 407         ---help---
 408           Support for IPsec tunnel mode.
 409
 410           If unsure, say Y.
 411
 412 config INET_XFRM_MODE_BEET
 413         tristate "IP: IPsec BEET mode"
 414         default y
 415         select XFRM
 416         ---help---
 417           Support for IPsec BEET mode.
 418
 419           If unsure, say Y.
 420
 421 config INET_DIAG
 422         tristate "INET: socket monitoring interface"
 423         default y
 424         ---help---
 425           Support for INET (TCP, DCCP, etc) socket monitoring interface used by
 426           native Linux tools such as ss. ss is included in iproute2, currently
 427           downloadable at:
 428
 429             http://www.linuxfoundation.org/collaborate/workgroups/networking/iproute2
 430
 431           If unsure, say Y.
 432
 433 config INET_TCP_DIAG
 434         depends on INET_DIAG
 435         def_tristate INET_DIAG
 436
 437 config INET_UDP_DIAG
 438         tristate "UDP: socket monitoring interface"
 439         depends on INET_DIAG && (IPV6 || IPV6=n)
 440         default n
 441         ---help---
 442           Support for UDP socket monitoring interface used by the ss tool.
 443           If unsure, say Y.
 444
 445 config INET_RAW_DIAG
 446         tristate "RAW: socket monitoring interface"
 447         depends on INET_DIAG && (IPV6 || IPV6=n)
 448         default n
 449         ---help---
 450           Support for RAW socket monitoring interface used by the ss tool.
 451           If unsure, say Y.
 452
 453 config INET_DIAG_DESTROY
 454         bool "INET: allow privileged process to administratively close sockets"
 455         depends on INET_DIAG
 456         default n
 457         ---help---
 458           Provides a SOCK_DESTROY operation that allows privileged processes
 459           (e.g., a connection manager or a network administration tool such as
 460           ss) to close sockets opened by other processes. Closing a socket in
 461           this way interrupts any blocking read/write/connect operations on
 462           the socket and causes future socket calls to behave as if the socket
 463           had been disconnected.
 464           If unsure, say N.
 465
 466 menuconfig TCP_CONG_ADVANCED
 467         bool "TCP: advanced congestion control"
 468         ---help---
 469           Support for selection of various TCP congestion control
 470           modules.
 471
 472           Nearly all users can safely say no here, and a safe default
 473           selection will be made (CUBIC with new Reno as a fallback).
 474
 475           If unsure, say N.
 476
 477 if TCP_CONG_ADVANCED
 478
 479 config TCP_CONG_BIC
 480         tristate "Binary Increase Congestion (BIC) control"
 481         default m
 482         ---help---
 483         BIC-TCP is a sender-side only change that ensures a linear RTT
 484         fairness under large windows while offering both scalability and
 485         bounded TCP-friendliness. The protocol combines two schemes
 486         called additive increase and binary search increase. When the
 487         congestion window is large, additive increase with a large
 488         increment ensures linear RTT fairness as well as good
 489         scalability. Under small congestion windows, binary search
 490         increase provides TCP friendliness.
 491         See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/
 492
 493 config TCP_CONG_CUBIC
 494         tristate "CUBIC TCP"
 495         default y
 496         ---help---
 497         This is version 2.0 of BIC-TCP which uses a cubic growth function
 498         among other techniques.
 499         See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/cubic-paper.pdf
 500
 501 config TCP_CONG_WESTWOOD
 502         tristate "TCP Westwood+"
 503         default m
 504         ---help---
 505         TCP Westwood+ is a sender-side only modification of the TCP Reno
 506         protocol stack that optimizes the performance of TCP congestion
 507         control. It is based on end-to-end bandwidth estimation to set
 508         congestion window and slow start threshold after a congestion
 509         episode. Using this estimation, TCP Westwood+ adaptively sets a
 510         slow start threshold and a congestion window which takes into
 511         account the bandwidth used  at the time congestion is experienced.
 512         TCP Westwood+ significantly increases fairness wrt TCP Reno in
 513         wired networks and throughput over wireless links.
 514
 515 config TCP_CONG_HTCP
 516         tristate "H-TCP"
 517         default m
 518         ---help---
 519         H-TCP is a send-side only modifications of the TCP Reno
 520         protocol stack that optimizes the performance of TCP
 521         congestion control for high speed network links. It uses a
 522         modeswitch to change the alpha and beta parameters of TCP Reno
 523         based on network conditions and in a way so as to be fair with
 524         other Reno and H-TCP flows.
 525
 526 config TCP_CONG_HSTCP
 527         tristate "High Speed TCP"
 528         default n
 529         ---help---
 530         Sally Floyd's High Speed TCP (RFC 3649) congestion control.
 531         A modification to TCP's congestion control mechanism for use
 532         with large congestion windows. A table indicates how much to
 533         increase the congestion window by when an ACK is received.
 534         For more detail see http://www.icir.org/floyd/hstcp.html
 535
 536 config TCP_CONG_HYBLA
 537         tristate "TCP-Hybla congestion control algorithm"
 538         default n
 539         ---help---
 540         TCP-Hybla is a sender-side only change that eliminates penalization of
 541         long-RTT, large-bandwidth connections, like when satellite legs are
 542         involved, especially when sharing a common bottleneck with normal
 543         terrestrial connections.
 544
 545 config TCP_CONG_VEGAS
 546         tristate "TCP Vegas"
 547         default n
 548         ---help---
 549         TCP Vegas is a sender-side only change to TCP that anticipates
 550         the onset of congestion by estimating the bandwidth. TCP Vegas
 551         adjusts the sending rate by modifying the congestion
 552         window. TCP Vegas should provide less packet loss, but it is
 553         not as aggressive as TCP Reno.
 554
 555 config TCP_CONG_NV
 556        tristate "TCP NV"
 557        default n
 558        ---help---
 559        TCP NV is a follow up to TCP Vegas. It has been modified to deal with
 560        10G networks, measurement noise introduced by LRO, GRO and interrupt
 561        coalescence. In addition, it will decrease its cwnd multiplicatively
 562        instead of linearly.
 563
 564        Note that in general congestion avoidance (cwnd decreased when # packets
 565        queued grows) cannot coexist with congestion control (cwnd decreased only
 566        when there is packet loss) due to fairness issues. One scenario when they
 567        can coexist safely is when the CA flows have RTTs << CC flows RTTs.
 568
 569        For further details see http://www.brakmo.org/networking/tcp-nv/
 570
 571 config TCP_CONG_SCALABLE
 572         tristate "Scalable TCP"
 573         default n
 574         ---help---
 575         Scalable TCP is a sender-side only change to TCP which uses a
 576         MIMD congestion control algorithm which has some nice scaling
 577         properties, though is known to have fairness issues.
 578         See http://www.deneholme.net/tom/scalable/
 579
 580 config TCP_CONG_LP
 581         tristate "TCP Low Priority"
 582         default n
 583         ---help---
 584         TCP Low Priority (TCP-LP), a distributed algorithm whose goal is
 585         to utilize only the excess network bandwidth as compared to the
 586         ``fair share`` of bandwidth as targeted by TCP.
 587         See http://www-ece.rice.edu/networks/TCP-LP/
 588
 589 config TCP_CONG_VENO
 590         tristate "TCP Veno"
 591         default n
 592         ---help---
 593         TCP Veno is a sender-side only enhancement of TCP to obtain better
 594         throughput over wireless networks. TCP Veno makes use of state
 595         distinguishing to circumvent the difficult judgment of the packet loss
 596         type. TCP Veno cuts down less congestion window in response to random
 597         loss packets.
 598         See <http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=1177186>
 599
 600 config TCP_CONG_YEAH
 601         tristate "YeAH TCP"
 602         select TCP_CONG_VEGAS
 603         default n
 604         ---help---
 605         YeAH-TCP is a sender-side high-speed enabled TCP congestion control
 606         algorithm, which uses a mixed loss/delay approach to compute the
 607         congestion window. It's design goals target high efficiency,
 608         internal, RTT and Reno fairness, resilience to link loss while
 609         keeping network elements load as low as possible.
 610
 611         For further details look here:
 612           http://wil.cs.caltech.edu/pfldnet2007/paper/YeAH_TCP.pdf
 613
 614 config TCP_CONG_ILLINOIS
 615         tristate "TCP Illinois"
 616         default n
 617         ---help---
 618         TCP-Illinois is a sender-side modification of TCP Reno for
 619         high speed long delay links. It uses round-trip-time to
 620         adjust the alpha and beta parameters to achieve a higher average
 621         throughput and maintain fairness.
 622
 623         For further details see:
 624           http://www.ews.uiuc.edu/~shaoliu/tcpillinois/index.html
 625
 626 config TCP_CONG_DCTCP
 627         tristate "DataCenter TCP (DCTCP)"
 628         default n
 629         ---help---
 630         DCTCP leverages Explicit Congestion Notification (ECN) in the network to
 631         provide multi-bit feedback to the end hosts. It is designed to provide:
 632
 633         - High burst tolerance (incast due to partition/aggregate),
 634         - Low latency (short flows, queries),
 635         - High throughput (continuous data updates, large file transfers) with
 636           commodity, shallow-buffered switches.
 637
 638         All switches in the data center network running DCTCP must support
 639         ECN marking and be configured for marking when reaching defined switch
 640         buffer thresholds. The default ECN marking threshold heuristic for
 641         DCTCP on switches is 20 packets (30KB) at 1Gbps, and 65 packets
 642         (~100KB) at 10Gbps, but might need further careful tweaking.
 643
 644         For further details see:
 645           http://simula.stanford.edu/~alizade/Site/DCTCP_files/dctcp-final.pdf
 646
 647 config TCP_CONG_CDG
 648         tristate "CAIA Delay-Gradient (CDG)"
 649         default n
 650         ---help---
 651         CAIA Delay-Gradient (CDG) is a TCP congestion control that modifies
 652         the TCP sender in order to:
 653
 654           o Use the delay gradient as a congestion signal.
 655           o Back off with an average probability that is independent of the RTT.
 656           o Coexist with flows that use loss-based congestion control.
 657           o Tolerate packet loss unrelated to congestion.
 658
 659         For further details see:
 660           D.A. Hayes and G. Armitage. "Revisiting TCP congestion control using
 661           delay gradients." In Networking 2011. Preprint: http://goo.gl/No3vdg
 662
 663 config TCP_CONG_BBR
 664         tristate "BBR TCP"
 665         default n
 666         ---help---
 667
 668         BBR (Bottleneck Bandwidth and RTT) TCP congestion control aims to
 669         maximize network utilization and minimize queues. It builds an explicit
 670         model of the the bottleneck delivery rate and path round-trip
 671         propagation delay. It tolerates packet loss and delay unrelated to
 672         congestion. It can operate over LAN, WAN, cellular, wifi, or cable
 673         modem links. It can coexist with flows that use loss-based congestion
 674         control, and can operate with shallow buffers, deep buffers,
 675         bufferbloat, policers, or AQM schemes that do not provide a delay
 676         signal. It requires the fq ("Fair Queue") pacing packet scheduler.
 677
 678 choice
 679         prompt "Default TCP congestion control"
 680         default DEFAULT_CUBIC
 681         help
 682           Select the TCP congestion control that will be used by default
 683           for all connections.
 684
 685         config DEFAULT_BIC
 686                 bool "Bic" if TCP_CONG_BIC=y
 687
 688         config DEFAULT_CUBIC
 689                 bool "Cubic" if TCP_CONG_CUBIC=y
 690
 691         config DEFAULT_HTCP
 692                 bool "Htcp" if TCP_CONG_HTCP=y
 693
 694         config DEFAULT_HYBLA
 695                 bool "Hybla" if TCP_CONG_HYBLA=y
 696
 697         config DEFAULT_VEGAS
 698                 bool "Vegas" if TCP_CONG_VEGAS=y
 699
 700         config DEFAULT_VENO
 701                 bool "Veno" if TCP_CONG_VENO=y
 702
 703         config DEFAULT_WESTWOOD
 704                 bool "Westwood" if TCP_CONG_WESTWOOD=y
 705
 706         config DEFAULT_DCTCP
 707                 bool "DCTCP" if TCP_CONG_DCTCP=y
 708
 709         config DEFAULT_CDG
 710                 bool "CDG" if TCP_CONG_CDG=y
 711
 712         config DEFAULT_BBR
 713                 bool "BBR" if TCP_CONG_BBR=y
 714
 715         config DEFAULT_RENO
 716                 bool "Reno"
 717 endchoice
 718
 719 endif
 720
 721 config TCP_CONG_CUBIC
 722         tristate
 723         depends on !TCP_CONG_ADVANCED
 724         default y
 725
 726 config DEFAULT_TCP_CONG
 727         string
 728         default "bic" if DEFAULT_BIC
 729         default "cubic" if DEFAULT_CUBIC
 730         default "htcp" if DEFAULT_HTCP
 731         default "hybla" if DEFAULT_HYBLA
 732         default "vegas" if DEFAULT_VEGAS
 733         default "westwood" if DEFAULT_WESTWOOD
 734         default "veno" if DEFAULT_VENO
 735         default "reno" if DEFAULT_RENO
 736         default "dctcp" if DEFAULT_DCTCP
 737         default "cdg" if DEFAULT_CDG
 738         default "bbr" if DEFAULT_BBR
 739         default "cubic"
 740
 741 config TCP_MD5SIG
 742         bool "TCP: MD5 Signature Option support (RFC2385)"
 743         select CRYPTO
 744         select CRYPTO_MD5
 745         ---help---
 746           RFC2385 specifies a method of giving MD5 protection to TCP sessions.
 747           Its main (only?) use is to protect BGP sessions between core routers
 748           on the Internet.
 749
 750           If unsure, say N.