net/ipv4/Kconfig

   1 # SPDX-License-Identifier: GPL-2.0-only
   2 #
   3 # IP configuration
   4 #
   5 config IP_MULTICAST
   6         bool "IP: multicasting"
   7         help
   8           This is code for addressing several networked computers at once,
   9           enlarging your kernel by about 2 KB. You need multicasting if you
  10           intend to participate in the MBONE, a high bandwidth network on top
  11           of the Internet which carries audio and video broadcasts. More
  12           information about the MBONE is on the WWW at
  13           <https://www.savetz.com/mbone/>. For most people, it's safe to say N.
  14
  15 config IP_ADVANCED_ROUTER
  16         bool "IP: advanced router"
  17         help
  18           If you intend to run your Linux box mostly as a router, i.e. as a
  19           computer that forwards and redistributes network packets, say Y; you
  20           will then be presented with several options that allow more precise
  21           control about the routing process.
  22
  23           The answer to this question won't directly affect the kernel:
  24           answering N will just cause the configurator to skip all the
  25           questions about advanced routing.
  26
  27           Note that your box can only act as a router if you enable IP
  28           forwarding in your kernel; you can do that by saying Y to "/proc
  29           file system support" and "Sysctl support" below and executing the
  30           line
  31
  32           echo "1" > /proc/sys/net/ipv4/ip_forward
  33
  34           at boot time after the /proc file system has been mounted.
  35
  36           If you turn on IP forwarding, you should consider the rp_filter, which
  37           automatically rejects incoming packets if the routing table entry
  38           for their source address doesn't match the network interface they're
  39           arriving on. This has security advantages because it prevents the
  40           so-called IP spoofing, however it can pose problems if you use
  41           asymmetric routing (packets from you to a host take a different path
  42           than packets from that host to you) or if you operate a non-routing
  43           host which has several IP addresses on different interfaces. To turn
  44           rp_filter on use:
  45
  46           echo 1 > /proc/sys/net/ipv4/conf/<device>/rp_filter
  47            or
  48           echo 1 > /proc/sys/net/ipv4/conf/all/rp_filter
  49
  50           Note that some distributions enable it in startup scripts.
  51           For details about rp_filter strict and loose mode read
  52           <file:Documentation/networking/ip-sysctl.rst>.
  53
  54           If unsure, say N here.
  55
  56 config IP_FIB_TRIE_STATS
  57         bool "FIB TRIE statistics"
  58         depends on IP_ADVANCED_ROUTER
  59         help
  60           Keep track of statistics on structure of FIB TRIE table.
  61           Useful for testing and measuring TRIE performance.
  62
  63 config IP_MULTIPLE_TABLES
  64         bool "IP: policy routing"
  65         depends on IP_ADVANCED_ROUTER
  66         select FIB_RULES
  67         help
  68           Normally, a router decides what to do with a received packet based
  69           solely on the packet's final destination address. If you say Y here,
  70           the Linux router will also be able to take the packet's source
  71           address into account. Furthermore, the TOS (Type-Of-Service) field
  72           of the packet can be used for routing decisions as well.
  73
  74           If you need more information, see the Linux Advanced
  75           Routing and Traffic Control documentation at
  76           <https://lartc.org/howto/lartc.rpdb.html>
  77
  78           If unsure, say N.
  79
  80 config IP_ROUTE_MULTIPATH
  81         bool "IP: equal cost multipath"
  82         depends on IP_ADVANCED_ROUTER
  83         help
  84           Normally, the routing tables specify a single action to be taken in
  85           a deterministic manner for a given packet. If you say Y here
  86           however, it becomes possible to attach several actions to a packet
  87           pattern, in effect specifying several alternative paths to travel
  88           for those packets. The router considers all these paths to be of
  89           equal "cost" and chooses one of them in a non-deterministic fashion
  90           if a matching packet arrives.
  91
  92 config IP_ROUTE_VERBOSE
  93         bool "IP: verbose route monitoring"
  94         depends on IP_ADVANCED_ROUTER
  95         help
  96           If you say Y here, which is recommended, then the kernel will print
  97           verbose messages regarding the routing, for example warnings about
  98           received packets which look strange and could be evidence of an
  99           attack or a misconfigured system somewhere. The information is
 100           handled by the klogd daemon which is responsible for kernel messages
 101           ("man klogd").
 102
 103 config IP_ROUTE_CLASSID
 104         bool
 105
 106 config IP_PNP
 107         bool "IP: kernel level autoconfiguration"
 108         help
 109           This enables automatic configuration of IP addresses of devices and
 110           of the routing table during kernel boot, based on either information
 111           supplied on the kernel command line or by BOOTP or RARP protocols.
 112           You need to say Y only for diskless machines requiring network
 113           access to boot (in which case you want to say Y to "Root file system
 114           on NFS" as well), because all other machines configure the network
 115           in their startup scripts.
 116
 117 config IP_PNP_DHCP
 118         bool "IP: DHCP support"
 119         depends on IP_PNP
 120         help
 121           If you want your Linux box to mount its whole root file system (the
 122           one containing the directory /) from some other computer over the
 123           net via NFS and you want the IP address of your computer to be
 124           discovered automatically at boot time using the DHCP protocol (a
 125           special protocol designed for doing this job), say Y here. In case
 126           the boot ROM of your network card was designed for booting Linux and
 127           does DHCP itself, providing all necessary information on the kernel
 128           command line, you can say N here.
 129
 130           If unsure, say Y. Note that if you want to use DHCP, a DHCP server
 131           must be operating on your network.  Read
 132           <file:Documentation/admin-guide/nfs/nfsroot.rst> for details.
 133
 134 config IP_PNP_BOOTP
 135         bool "IP: BOOTP support"
 136         depends on IP_PNP
 137         help
 138           If you want your Linux box to mount its whole root file system (the
 139           one containing the directory /) from some other computer over the
 140           net via NFS and you want the IP address of your computer to be
 141           discovered automatically at boot time using the BOOTP protocol (a
 142           special protocol designed for doing this job), say Y here. In case
 143           the boot ROM of your network card was designed for booting Linux and
 144           does BOOTP itself, providing all necessary information on the kernel
 145           command line, you can say N here. If unsure, say Y. Note that if you
 146           want to use BOOTP, a BOOTP server must be operating on your network.
 147           Read <file:Documentation/admin-guide/nfs/nfsroot.rst> for details.
 148
 149 config IP_PNP_RARP
 150         bool "IP: RARP support"
 151         depends on IP_PNP
 152         help
 153           If you want your Linux box to mount its whole root file system (the
 154           one containing the directory /) from some other computer over the
 155           net via NFS and you want the IP address of your computer to be
 156           discovered automatically at boot time using the RARP protocol (an
 157           older protocol which is being obsoleted by BOOTP and DHCP), say Y
 158           here. Note that if you want to use RARP, a RARP server must be
 159           operating on your network. Read
 160           <file:Documentation/admin-guide/nfs/nfsroot.rst> for details.
 161
 162 config NET_IPIP
 163         tristate "IP: tunneling"
 164         select INET_TUNNEL
 165         select NET_IP_TUNNEL
 166         help
 167           Tunneling means encapsulating data of one protocol type within
 168           another protocol and sending it over a channel that understands the
 169           encapsulating protocol. This particular tunneling driver implements
 170           encapsulation of IP within IP, which sounds kind of pointless, but
 171           can be useful if you want to make your (or some other) machine
 172           appear on a different network than it physically is, or to use
 173           mobile-IP facilities (allowing laptops to seamlessly move between
 174           networks without changing their IP addresses).
 175
 176           Saying Y to this option will produce two modules ( = code which can
 177           be inserted in and removed from the running kernel whenever you
 178           want). Most people won't need this and can say N.
 179
 180 config NET_IPGRE_DEMUX
 181         tristate "IP: GRE demultiplexer"
 182         help
 183           This is helper module to demultiplex GRE packets on GRE version field criteria.
 184           Required by ip_gre and pptp modules.
 185
 186 config NET_IP_TUNNEL
 187         tristate
 188         select DST_CACHE
 189         select GRO_CELLS
 190         default n
 191
 192 config NET_IPGRE
 193         tristate "IP: GRE tunnels over IP"
 194         depends on (IPV6 || IPV6=n) && NET_IPGRE_DEMUX
 195         select NET_IP_TUNNEL
 196         help
 197           Tunneling means encapsulating data of one protocol type within
 198           another protocol and sending it over a channel that understands the
 199           encapsulating protocol. This particular tunneling driver implements
 200           GRE (Generic Routing Encapsulation) and at this time allows
 201           encapsulating of IPv4 or IPv6 over existing IPv4 infrastructure.
 202           This driver is useful if the other endpoint is a Cisco router: Cisco
 203           likes GRE much better than the other Linux tunneling driver ("IP
 204           tunneling" above). In addition, GRE allows multicast redistribution
 205           through the tunnel.
 206
 207 config NET_IPGRE_BROADCAST
 208         bool "IP: broadcast GRE over IP"
 209         depends on IP_MULTICAST && NET_IPGRE
 210         help
 211           One application of GRE/IP is to construct a broadcast WAN (Wide Area
 212           Network), which looks like a normal Ethernet LAN (Local Area
 213           Network), but can be distributed all over the Internet. If you want
 214           to do that, say Y here and to "IP multicast routing" below.
 215
 216 config IP_MROUTE_COMMON
 217         bool
 218         depends on IP_MROUTE || IPV6_MROUTE
 219
 220 config IP_MROUTE
 221         bool "IP: multicast routing"
 222         depends on IP_MULTICAST
 223         select IP_MROUTE_COMMON
 224         help
 225           This is used if you want your machine to act as a router for IP
 226           packets that have several destination addresses. It is needed on the
 227           MBONE, a high bandwidth network on top of the Internet which carries
 228           audio and video broadcasts. In order to do that, you would most
 229           likely run the program mrouted. If you haven't heard about it, you
 230           don't need it.
 231
 232 config IP_MROUTE_MULTIPLE_TABLES
 233         bool "IP: multicast policy routing"
 234         depends on IP_MROUTE && IP_ADVANCED_ROUTER
 235         select FIB_RULES
 236         help
 237           Normally, a multicast router runs a userspace daemon and decides
 238           what to do with a multicast packet based on the source and
 239           destination addresses. If you say Y here, the multicast router
 240           will also be able to take interfaces and packet marks into
 241           account and run multiple instances of userspace daemons
 242           simultaneously, each one handling a single table.
 243
 244           If unsure, say N.
 245
 246 config IP_PIMSM_V1
 247         bool "IP: PIM-SM version 1 support"
 248         depends on IP_MROUTE
 249         help
 250           Kernel side support for Sparse Mode PIM (Protocol Independent
 251           Multicast) version 1. This multicast routing protocol is used widely
 252           because Cisco supports it. You need special software to use it
 253           (pimd-v1). Please see <http://netweb.usc.edu/pim/> for more
 254           information about PIM.
 255
 256           Say Y if you want to use PIM-SM v1. Note that you can say N here if
 257           you just want to use Dense Mode PIM.
 258
 259 config IP_PIMSM_V2
 260         bool "IP: PIM-SM version 2 support"
 261         depends on IP_MROUTE
 262         help
 263           Kernel side support for Sparse Mode PIM version 2. In order to use
 264           this, you need an experimental routing daemon supporting it (pimd or
 265           gated-5). This routing protocol is not used widely, so say N unless
 266           you want to play with it.
 267
 268 config SYN_COOKIES
 269         bool "IP: TCP syncookie support"
 270         help
 271           Normal TCP/IP networking is open to an attack known as "SYN
 272           flooding". This denial-of-service attack prevents legitimate remote
 273           users from being able to connect to your computer during an ongoing
 274           attack and requires very little work from the attacker, who can
 275           operate from anywhere on the Internet.
 276
 277           SYN cookies provide protection against this type of attack. If you
 278           say Y here, the TCP/IP stack will use a cryptographic challenge
 279           protocol known as "SYN cookies" to enable legitimate users to
 280           continue to connect, even when your machine is under attack. There
 281           is no need for the legitimate users to change their TCP/IP software;
 282           SYN cookies work transparently to them. For technical information
 283           about SYN cookies, check out <https://cr.yp.to/syncookies.html>.
 284
 285           If you are SYN flooded, the source address reported by the kernel is
 286           likely to have been forged by the attacker; it is only reported as
 287           an aid in tracing the packets to their actual source and should not
 288           be taken as absolute truth.
 289
 290           SYN cookies may prevent correct error reporting on clients when the
 291           server is really overloaded. If this happens frequently better turn
 292           them off.
 293
 294           If you say Y here, you can disable SYN cookies at run time by
 295           saying Y to "/proc file system support" and
 296           "Sysctl support" below and executing the command
 297
 298           echo 0 > /proc/sys/net/ipv4/tcp_syncookies
 299
 300           after the /proc file system has been mounted.
 301
 302           If unsure, say N.
 303
 304 config NET_IPVTI
 305         tristate "Virtual (secure) IP: tunneling"
 306         depends on IPV6 || IPV6=n
 307         select INET_TUNNEL
 308         select NET_IP_TUNNEL
 309         select XFRM
 310         help
 311           Tunneling means encapsulating data of one protocol type within
 312           another protocol and sending it over a channel that understands the
 313           encapsulating protocol. This can be used with xfrm mode tunnel to give
 314           the notion of a secure tunnel for IPSEC and then use routing protocol
 315           on top.
 316
 317 config NET_UDP_TUNNEL
 318         tristate
 319         select NET_IP_TUNNEL
 320         default n
 321
 322 config NET_FOU
 323         tristate "IP: Foo (IP protocols) over UDP"
 324         select XFRM
 325         select NET_UDP_TUNNEL
 326         help
 327           Foo over UDP allows any IP protocol to be directly encapsulated
 328           over UDP include tunnels (IPIP, GRE, SIT). By encapsulating in UDP
 329           network mechanisms and optimizations for UDP (such as ECMP
 330           and RSS) can be leveraged to provide better service.
 331
 332 config NET_FOU_IP_TUNNELS
 333         bool "IP: FOU encapsulation of IP tunnels"
 334         depends on NET_IPIP || NET_IPGRE || IPV6_SIT
 335         select NET_FOU
 336         help
 337           Allow configuration of FOU or GUE encapsulation for IP tunnels.
 338           When this option is enabled IP tunnels can be configured to use
 339           FOU or GUE encapsulation.
 340
 341 config INET_AH
 342         tristate "IP: AH transformation"
 343         select XFRM_AH
 344         help
 345           Support for IPsec AH (Authentication Header).
 346
 347           AH can be used with various authentication algorithms.  Besides
 348           enabling AH support itself, this option enables the generic
 349           implementations of the algorithms that RFC 8221 lists as MUST be
 350           implemented.  If you need any other algorithms, you'll need to enable
 351           them in the crypto API.  You should also enable accelerated
 352           implementations of any needed algorithms when available.
 353
 354           If unsure, say Y.
 355
 356 config INET_ESP
 357         tristate "IP: ESP transformation"
 358         select XFRM_ESP
 359         help
 360           Support for IPsec ESP (Encapsulating Security Payload).
 361
 362           ESP can be used with various encryption and authentication algorithms.
 363           Besides enabling ESP support itself, this option enables the generic
 364           implementations of the algorithms that RFC 8221 lists as MUST be
 365           implemented.  If you need any other algorithms, you'll need to enable
 366           them in the crypto API.  You should also enable accelerated
 367           implementations of any needed algorithms when available.
 368
 369           If unsure, say Y.
 370
 371 config INET_ESP_OFFLOAD
 372         tristate "IP: ESP transformation offload"
 373         depends on INET_ESP
 374         select XFRM_OFFLOAD
 375         default n
 376         help
 377           Support for ESP transformation offload. This makes sense
 378           only if this system really does IPsec and want to do it
 379           with high throughput. A typical desktop system does not
 380           need it, even if it does IPsec.
 381
 382           If unsure, say N.
 383
 384 config INET_ESPINTCP
 385         bool "IP: ESP in TCP encapsulation (RFC 8229)"
 386         depends on XFRM && INET_ESP
 387         select STREAM_PARSER
 388         select NET_SOCK_MSG
 389         select XFRM_ESPINTCP
 390         help
 391           Support for RFC 8229 encapsulation of ESP and IKE over
 392           TCP/IPv4 sockets.
 393
 394           If unsure, say N.
 395
 396 config INET_IPCOMP
 397         tristate "IP: IPComp transformation"
 398         select INET_XFRM_TUNNEL
 399         select XFRM_IPCOMP
 400         help
 401           Support for IP Payload Compression Protocol (IPComp) (RFC3173),
 402           typically needed for IPsec.
 403
 404           If unsure, say Y.
 405
 406 config INET_TABLE_PERTURB_ORDER
 407         int "INET: Source port perturbation table size (as power of 2)" if EXPERT
 408         default 16
 409         help
 410           Source port perturbation table size (as power of 2) for
 411           RFC 6056 3.3.4.  Algorithm 4: Double-Hash Port Selection Algorithm.
 412
 413           The default is almost always what you want.
 414           Only change this if you know what you are doing.
 415
 416 config INET_XFRM_TUNNEL
 417         tristate
 418         select INET_TUNNEL
 419         default n
 420
 421 config INET_TUNNEL
 422         tristate
 423         default n
 424
 425 config INET_DIAG
 426         tristate "INET: socket monitoring interface"
 427         default y
 428         help
 429           Support for INET (TCP, DCCP, etc) socket monitoring interface used by
 430           native Linux tools such as ss. ss is included in iproute2, currently
 431           downloadable at:
 432
 433             http://www.linuxfoundation.org/collaborate/workgroups/networking/iproute2
 434
 435           If unsure, say Y.
 436
 437 config INET_TCP_DIAG
 438         depends on INET_DIAG
 439         def_tristate INET_DIAG
 440
 441 config INET_UDP_DIAG
 442         tristate "UDP: socket monitoring interface"
 443         depends on INET_DIAG && (IPV6 || IPV6=n)
 444         default n
 445         help
 446           Support for UDP socket monitoring interface used by the ss tool.
 447           If unsure, say Y.
 448
 449 config INET_RAW_DIAG
 450         tristate "RAW: socket monitoring interface"
 451         depends on INET_DIAG && (IPV6 || IPV6=n)
 452         default n
 453         help
 454           Support for RAW socket monitoring interface used by the ss tool.
 455           If unsure, say Y.
 456
 457 config INET_DIAG_DESTROY
 458         bool "INET: allow privileged process to administratively close sockets"
 459         depends on INET_DIAG
 460         default n
 461         help
 462           Provides a SOCK_DESTROY operation that allows privileged processes
 463           (e.g., a connection manager or a network administration tool such as
 464           ss) to close sockets opened by other processes. Closing a socket in
 465           this way interrupts any blocking read/write/connect operations on
 466           the socket and causes future socket calls to behave as if the socket
 467           had been disconnected.
 468           If unsure, say N.
 469
 470 menuconfig TCP_CONG_ADVANCED
 471         bool "TCP: advanced congestion control"
 472         help
 473           Support for selection of various TCP congestion control
 474           modules.
 475
 476           Nearly all users can safely say no here, and a safe default
 477           selection will be made (CUBIC with new Reno as a fallback).
 478
 479           If unsure, say N.
 480
 481 if TCP_CONG_ADVANCED
 482
 483 config TCP_CONG_BIC
 484         tristate "Binary Increase Congestion (BIC) control"
 485         default m
 486         help
 487           BIC-TCP is a sender-side only change that ensures a linear RTT
 488           fairness under large windows while offering both scalability and
 489           bounded TCP-friendliness. The protocol combines two schemes
 490           called additive increase and binary search increase. When the
 491           congestion window is large, additive increase with a large
 492           increment ensures linear RTT fairness as well as good
 493           scalability. Under small congestion windows, binary search
 494           increase provides TCP friendliness.
 495           See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/
 496
 497 config TCP_CONG_CUBIC
 498         tristate "CUBIC TCP"
 499         default y
 500         help
 501           This is version 2.0 of BIC-TCP which uses a cubic growth function
 502           among other techniques.
 503           See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/cubic-paper.pdf
 504
 505 config TCP_CONG_WESTWOOD
 506         tristate "TCP Westwood+"
 507         default m
 508         help
 509           TCP Westwood+ is a sender-side only modification of the TCP Reno
 510           protocol stack that optimizes the performance of TCP congestion
 511           control. It is based on end-to-end bandwidth estimation to set
 512           congestion window and slow start threshold after a congestion
 513           episode. Using this estimation, TCP Westwood+ adaptively sets a
 514           slow start threshold and a congestion window which takes into
 515           account the bandwidth used  at the time congestion is experienced.
 516           TCP Westwood+ significantly increases fairness wrt TCP Reno in
 517           wired networks and throughput over wireless links.
 518
 519 config TCP_CONG_HTCP
 520         tristate "H-TCP"
 521         default m
 522         help
 523           H-TCP is a send-side only modifications of the TCP Reno
 524           protocol stack that optimizes the performance of TCP
 525           congestion control for high speed network links. It uses a
 526           modeswitch to change the alpha and beta parameters of TCP Reno
 527           based on network conditions and in a way so as to be fair with
 528           other Reno and H-TCP flows.
 529
 530 config TCP_CONG_HSTCP
 531         tristate "High Speed TCP"
 532         default n
 533         help
 534           Sally Floyd's High Speed TCP (RFC 3649) congestion control.
 535           A modification to TCP's congestion control mechanism for use
 536           with large congestion windows. A table indicates how much to
 537           increase the congestion window by when an ACK is received.
 538           For more detail see https://www.icir.org/floyd/hstcp.html
 539
 540 config TCP_CONG_HYBLA
 541         tristate "TCP-Hybla congestion control algorithm"
 542         default n
 543         help
 544           TCP-Hybla is a sender-side only change that eliminates penalization of
 545           long-RTT, large-bandwidth connections, like when satellite legs are
 546           involved, especially when sharing a common bottleneck with normal
 547           terrestrial connections.
 548
 549 config TCP_CONG_VEGAS
 550         tristate "TCP Vegas"
 551         default n
 552         help
 553           TCP Vegas is a sender-side only change to TCP that anticipates
 554           the onset of congestion by estimating the bandwidth. TCP Vegas
 555           adjusts the sending rate by modifying the congestion
 556           window. TCP Vegas should provide less packet loss, but it is
 557           not as aggressive as TCP Reno.
 558
 559 config TCP_CONG_NV
 560         tristate "TCP NV"
 561         default n
 562         help
 563           TCP NV is a follow up to TCP Vegas. It has been modified to deal with
 564           10G networks, measurement noise introduced by LRO, GRO and interrupt
 565           coalescence. In addition, it will decrease its cwnd multiplicatively
 566           instead of linearly.
 567
 568           Note that in general congestion avoidance (cwnd decreased when # packets
 569           queued grows) cannot coexist with congestion control (cwnd decreased only
 570           when there is packet loss) due to fairness issues. One scenario when they
 571           can coexist safely is when the CA flows have RTTs << CC flows RTTs.
 572
 573           For further details see http://www.brakmo.org/networking/tcp-nv/
 574
 575 config TCP_CONG_SCALABLE
 576         tristate "Scalable TCP"
 577         default n
 578         help
 579           Scalable TCP is a sender-side only change to TCP which uses a
 580           MIMD congestion control algorithm which has some nice scaling
 581           properties, though is known to have fairness issues.
 582           See http://www.deneholme.net/tom/scalable/
 583
 584 config TCP_CONG_LP
 585         tristate "TCP Low Priority"
 586         default n
 587         help
 588           TCP Low Priority (TCP-LP), a distributed algorithm whose goal is
 589           to utilize only the excess network bandwidth as compared to the
 590           ``fair share`` of bandwidth as targeted by TCP.
 591           See http://www-ece.rice.edu/networks/TCP-LP/
 592
 593 config TCP_CONG_VENO
 594         tristate "TCP Veno"
 595         default n
 596         help
 597           TCP Veno is a sender-side only enhancement of TCP to obtain better
 598           throughput over wireless networks. TCP Veno makes use of state
 599           distinguishing to circumvent the difficult judgment of the packet loss
 600           type. TCP Veno cuts down less congestion window in response to random
 601           loss packets.
 602           See <http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=1177186>
 603
 604 config TCP_CONG_YEAH
 605         tristate "YeAH TCP"
 606         select TCP_CONG_VEGAS
 607         default n
 608         help
 609           YeAH-TCP is a sender-side high-speed enabled TCP congestion control
 610           algorithm, which uses a mixed loss/delay approach to compute the
 611           congestion window. It's design goals target high efficiency,
 612           internal, RTT and Reno fairness, resilience to link loss while
 613           keeping network elements load as low as possible.
 614
 615           For further details look here:
 616             http://wil.cs.caltech.edu/pfldnet2007/paper/YeAH_TCP.pdf
 617
 618 config TCP_CONG_ILLINOIS
 619         tristate "TCP Illinois"
 620         default n
 621         help
 622           TCP-Illinois is a sender-side modification of TCP Reno for
 623           high speed long delay links. It uses round-trip-time to
 624           adjust the alpha and beta parameters to achieve a higher average
 625           throughput and maintain fairness.
 626
 627           For further details see:
 628             http://www.ews.uiuc.edu/~shaoliu/tcpillinois/index.html
 629
 630 config TCP_CONG_DCTCP
 631         tristate "DataCenter TCP (DCTCP)"
 632         default n
 633         help
 634           DCTCP leverages Explicit Congestion Notification (ECN) in the network to
 635           provide multi-bit feedback to the end hosts. It is designed to provide:
 636
 637           - High burst tolerance (incast due to partition/aggregate),
 638           - Low latency (short flows, queries),
 639           - High throughput (continuous data updates, large file transfers) with
 640             commodity, shallow-buffered switches.
 641
 642           All switches in the data center network running DCTCP must support
 643           ECN marking and be configured for marking when reaching defined switch
 644           buffer thresholds. The default ECN marking threshold heuristic for
 645           DCTCP on switches is 20 packets (30KB) at 1Gbps, and 65 packets
 646           (~100KB) at 10Gbps, but might need further careful tweaking.
 647
 648           For further details see:
 649             http://simula.stanford.edu/~alizade/Site/DCTCP_files/dctcp-final.pdf
 650
 651 config TCP_CONG_CDG
 652         tristate "CAIA Delay-Gradient (CDG)"
 653         default n
 654         help
 655           CAIA Delay-Gradient (CDG) is a TCP congestion control that modifies
 656           the TCP sender in order to:
 657
 658           o Use the delay gradient as a congestion signal.
 659           o Back off with an average probability that is independent of the RTT.
 660           o Coexist with flows that use loss-based congestion control.
 661           o Tolerate packet loss unrelated to congestion.
 662
 663           For further details see:
 664             D.A. Hayes and G. Armitage. "Revisiting TCP congestion control using
 665             delay gradients." In Networking 2011. Preprint: http://goo.gl/No3vdg
 666
 667 config TCP_CONG_BBR
 668         tristate "BBR TCP"
 669         default n
 670         help
 671
 672           BBR (Bottleneck Bandwidth and RTT) TCP congestion control aims to
 673           maximize network utilization and minimize queues. It builds an explicit
 674           model of the bottleneck delivery rate and path round-trip propagation
 675           delay. It tolerates packet loss and delay unrelated to congestion. It
 676           can operate over LAN, WAN, cellular, wifi, or cable modem links. It can
 677           coexist with flows that use loss-based congestion control, and can
 678           operate with shallow buffers, deep buffers, bufferbloat, policers, or
 679           AQM schemes that do not provide a delay signal. It requires the fq
 680           ("Fair Queue") pacing packet scheduler.
 681
 682 choice
 683         prompt "Default TCP congestion control"
 684         default DEFAULT_CUBIC
 685         help
 686           Select the TCP congestion control that will be used by default
 687           for all connections.
 688
 689         config DEFAULT_BIC
 690                 bool "Bic" if TCP_CONG_BIC=y
 691
 692         config DEFAULT_CUBIC
 693                 bool "Cubic" if TCP_CONG_CUBIC=y
 694
 695         config DEFAULT_HTCP
 696                 bool "Htcp" if TCP_CONG_HTCP=y
 697
 698         config DEFAULT_HYBLA
 699                 bool "Hybla" if TCP_CONG_HYBLA=y
 700
 701         config DEFAULT_VEGAS
 702                 bool "Vegas" if TCP_CONG_VEGAS=y
 703
 704         config DEFAULT_VENO
 705                 bool "Veno" if TCP_CONG_VENO=y
 706
 707         config DEFAULT_WESTWOOD
 708                 bool "Westwood" if TCP_CONG_WESTWOOD=y
 709
 710         config DEFAULT_DCTCP
 711                 bool "DCTCP" if TCP_CONG_DCTCP=y
 712
 713         config DEFAULT_CDG
 714                 bool "CDG" if TCP_CONG_CDG=y
 715
 716         config DEFAULT_BBR
 717                 bool "BBR" if TCP_CONG_BBR=y
 718
 719         config DEFAULT_RENO
 720                 bool "Reno"
 721 endchoice
 722
 723 endif
 724
 725 config TCP_CONG_CUBIC
 726         tristate
 727         depends on !TCP_CONG_ADVANCED
 728         default y
 729
 730 config DEFAULT_TCP_CONG
 731         string
 732         default "bic" if DEFAULT_BIC
 733         default "cubic" if DEFAULT_CUBIC
 734         default "htcp" if DEFAULT_HTCP
 735         default "hybla" if DEFAULT_HYBLA
 736         default "vegas" if DEFAULT_VEGAS
 737         default "westwood" if DEFAULT_WESTWOOD
 738         default "veno" if DEFAULT_VENO
 739         default "reno" if DEFAULT_RENO
 740         default "dctcp" if DEFAULT_DCTCP
 741         default "cdg" if DEFAULT_CDG
 742         default "bbr" if DEFAULT_BBR
 743         default "cubic"
 744
 745 config TCP_MD5SIG
 746         bool "TCP: MD5 Signature Option support (RFC2385)"
 747         select CRYPTO
 748         select CRYPTO_MD5
 749         help
 750           RFC2385 specifies a method of giving MD5 protection to TCP sessions.
 751           Its main (only?) use is to protect BGP sessions between core routers
 752           on the Internet.
 753
 754           If unsure, say N.