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_XFRM_TUNNEL 407 tristate 408 select INET_TUNNEL 409 default n 410 411 config INET_TUNNEL 412 tristate 413 default n 414 415 config INET_DIAG 416 tristate "INET: socket monitoring interface" 417 default y 418 help 419 Support for INET (TCP, DCCP, etc) socket monitoring interface used by 420 native Linux tools such as ss. ss is included in iproute2, currently 421 downloadable at: 422 423 http://www.linuxfoundation.org/collaborate/workgroups/networking/iproute2 424 425 If unsure, say Y. 426 427 config INET_TCP_DIAG 428 depends on INET_DIAG 429 def_tristate INET_DIAG 430 431 config INET_UDP_DIAG 432 tristate "UDP: socket monitoring interface" 433 depends on INET_DIAG && (IPV6 || IPV6=n) 434 default n 435 help 436 Support for UDP socket monitoring interface used by the ss tool. 437 If unsure, say Y. 438 439 config INET_RAW_DIAG 440 tristate "RAW: socket monitoring interface" 441 depends on INET_DIAG && (IPV6 || IPV6=n) 442 default n 443 help 444 Support for RAW socket monitoring interface used by the ss tool. 445 If unsure, say Y. 446 447 config INET_DIAG_DESTROY 448 bool "INET: allow privileged process to administratively close sockets" 449 depends on INET_DIAG 450 default n 451 help 452 Provides a SOCK_DESTROY operation that allows privileged processes 453 (e.g., a connection manager or a network administration tool such as 454 ss) to close sockets opened by other processes. Closing a socket in 455 this way interrupts any blocking read/write/connect operations on 456 the socket and causes future socket calls to behave as if the socket 457 had been disconnected. 458 If unsure, say N. 459 460 menuconfig TCP_CONG_ADVANCED 461 bool "TCP: advanced congestion control" 462 help 463 Support for selection of various TCP congestion control 464 modules. 465 466 Nearly all users can safely say no here, and a safe default 467 selection will be made (CUBIC with new Reno as a fallback). 468 469 If unsure, say N. 470 471 if TCP_CONG_ADVANCED 472 473 config TCP_CONG_BIC 474 tristate "Binary Increase Congestion (BIC) control" 475 default m 476 help 477 BIC-TCP is a sender-side only change that ensures a linear RTT 478 fairness under large windows while offering both scalability and 479 bounded TCP-friendliness. The protocol combines two schemes 480 called additive increase and binary search increase. When the 481 congestion window is large, additive increase with a large 482 increment ensures linear RTT fairness as well as good 483 scalability. Under small congestion windows, binary search 484 increase provides TCP friendliness. 485 See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/ 486 487 config TCP_CONG_CUBIC 488 tristate "CUBIC TCP" 489 default y 490 help 491 This is version 2.0 of BIC-TCP which uses a cubic growth function 492 among other techniques. 493 See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/cubic-paper.pdf 494 495 config TCP_CONG_WESTWOOD 496 tristate "TCP Westwood+" 497 default m 498 help 499 TCP Westwood+ is a sender-side only modification of the TCP Reno 500 protocol stack that optimizes the performance of TCP congestion 501 control. It is based on end-to-end bandwidth estimation to set 502 congestion window and slow start threshold after a congestion 503 episode. Using this estimation, TCP Westwood+ adaptively sets a 504 slow start threshold and a congestion window which takes into 505 account the bandwidth used at the time congestion is experienced. 506 TCP Westwood+ significantly increases fairness wrt TCP Reno in 507 wired networks and throughput over wireless links. 508 509 config TCP_CONG_HTCP 510 tristate "H-TCP" 511 default m 512 help 513 H-TCP is a send-side only modifications of the TCP Reno 514 protocol stack that optimizes the performance of TCP 515 congestion control for high speed network links. It uses a 516 modeswitch to change the alpha and beta parameters of TCP Reno 517 based on network conditions and in a way so as to be fair with 518 other Reno and H-TCP flows. 519 520 config TCP_CONG_HSTCP 521 tristate "High Speed TCP" 522 default n 523 help 524 Sally Floyd's High Speed TCP (RFC 3649) congestion control. 525 A modification to TCP's congestion control mechanism for use 526 with large congestion windows. A table indicates how much to 527 increase the congestion window by when an ACK is received. 528 For more detail see https://www.icir.org/floyd/hstcp.html 529 530 config TCP_CONG_HYBLA 531 tristate "TCP-Hybla congestion control algorithm" 532 default n 533 help 534 TCP-Hybla is a sender-side only change that eliminates penalization of 535 long-RTT, large-bandwidth connections, like when satellite legs are 536 involved, especially when sharing a common bottleneck with normal 537 terrestrial connections. 538 539 config TCP_CONG_VEGAS 540 tristate "TCP Vegas" 541 default n 542 help 543 TCP Vegas is a sender-side only change to TCP that anticipates 544 the onset of congestion by estimating the bandwidth. TCP Vegas 545 adjusts the sending rate by modifying the congestion 546 window. TCP Vegas should provide less packet loss, but it is 547 not as aggressive as TCP Reno. 548 549 config TCP_CONG_NV 550 tristate "TCP NV" 551 default n 552 help 553 TCP NV is a follow up to TCP Vegas. It has been modified to deal with 554 10G networks, measurement noise introduced by LRO, GRO and interrupt 555 coalescence. In addition, it will decrease its cwnd multiplicatively 556 instead of linearly. 557 558 Note that in general congestion avoidance (cwnd decreased when # packets 559 queued grows) cannot coexist with congestion control (cwnd decreased only 560 when there is packet loss) due to fairness issues. One scenario when they 561 can coexist safely is when the CA flows have RTTs << CC flows RTTs. 562 563 For further details see http://www.brakmo.org/networking/tcp-nv/ 564 565 config TCP_CONG_SCALABLE 566 tristate "Scalable TCP" 567 default n 568 help 569 Scalable TCP is a sender-side only change to TCP which uses a 570 MIMD congestion control algorithm which has some nice scaling 571 properties, though is known to have fairness issues. 572 See http://www.deneholme.net/tom/scalable/ 573 574 config TCP_CONG_LP 575 tristate "TCP Low Priority" 576 default n 577 help 578 TCP Low Priority (TCP-LP), a distributed algorithm whose goal is 579 to utilize only the excess network bandwidth as compared to the 580 ``fair share`` of bandwidth as targeted by TCP. 581 See http://www-ece.rice.edu/networks/TCP-LP/ 582 583 config TCP_CONG_VENO 584 tristate "TCP Veno" 585 default n 586 help 587 TCP Veno is a sender-side only enhancement of TCP to obtain better 588 throughput over wireless networks. TCP Veno makes use of state 589 distinguishing to circumvent the difficult judgment of the packet loss 590 type. TCP Veno cuts down less congestion window in response to random 591 loss packets. 592 See <http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=1177186> 593 594 config TCP_CONG_YEAH 595 tristate "YeAH TCP" 596 select TCP_CONG_VEGAS 597 default n 598 help 599 YeAH-TCP is a sender-side high-speed enabled TCP congestion control 600 algorithm, which uses a mixed loss/delay approach to compute the 601 congestion window. It's design goals target high efficiency, 602 internal, RTT and Reno fairness, resilience to link loss while 603 keeping network elements load as low as possible. 604 605 For further details look here: 606 http://wil.cs.caltech.edu/pfldnet2007/paper/YeAH_TCP.pdf 607 608 config TCP_CONG_ILLINOIS 609 tristate "TCP Illinois" 610 default n 611 help 612 TCP-Illinois is a sender-side modification of TCP Reno for 613 high speed long delay links. It uses round-trip-time to 614 adjust the alpha and beta parameters to achieve a higher average 615 throughput and maintain fairness. 616 617 For further details see: 618 http://www.ews.uiuc.edu/~shaoliu/tcpillinois/index.html 619 620 config TCP_CONG_DCTCP 621 tristate "DataCenter TCP (DCTCP)" 622 default n 623 help 624 DCTCP leverages Explicit Congestion Notification (ECN) in the network to 625 provide multi-bit feedback to the end hosts. It is designed to provide: 626 627 - High burst tolerance (incast due to partition/aggregate), 628 - Low latency (short flows, queries), 629 - High throughput (continuous data updates, large file transfers) with 630 commodity, shallow-buffered switches. 631 632 All switches in the data center network running DCTCP must support 633 ECN marking and be configured for marking when reaching defined switch 634 buffer thresholds. The default ECN marking threshold heuristic for 635 DCTCP on switches is 20 packets (30KB) at 1Gbps, and 65 packets 636 (~100KB) at 10Gbps, but might need further careful tweaking. 637 638 For further details see: 639 http://simula.stanford.edu/~alizade/Site/DCTCP_files/dctcp-final.pdf 640 641 config TCP_CONG_CDG 642 tristate "CAIA Delay-Gradient (CDG)" 643 default n 644 help 645 CAIA Delay-Gradient (CDG) is a TCP congestion control that modifies 646 the TCP sender in order to: 647 648 o Use the delay gradient as a congestion signal. 649 o Back off with an average probability that is independent of the RTT. 650 o Coexist with flows that use loss-based congestion control. 651 o Tolerate packet loss unrelated to congestion. 652 653 For further details see: 654 D.A. Hayes and G. Armitage. "Revisiting TCP congestion control using 655 delay gradients." In Networking 2011. Preprint: http://goo.gl/No3vdg 656 657 config TCP_CONG_BBR 658 tristate "BBR TCP" 659 default n 660 help 661 662 BBR (Bottleneck Bandwidth and RTT) TCP congestion control aims to 663 maximize network utilization and minimize queues. It builds an explicit 664 model of the bottleneck delivery rate and path round-trip propagation 665 delay. It tolerates packet loss and delay unrelated to congestion. It 666 can operate over LAN, WAN, cellular, wifi, or cable modem links. It can 667 coexist with flows that use loss-based congestion control, and can 668 operate with shallow buffers, deep buffers, bufferbloat, policers, or 669 AQM schemes that do not provide a delay signal. It requires the fq 670 ("Fair Queue") pacing packet scheduler. 671 672 choice 673 prompt "Default TCP congestion control" 674 default DEFAULT_CUBIC 675 help 676 Select the TCP congestion control that will be used by default 677 for all connections. 678 679 config DEFAULT_BIC 680 bool "Bic" if TCP_CONG_BIC=y 681 682 config DEFAULT_CUBIC 683 bool "Cubic" if TCP_CONG_CUBIC=y 684 685 config DEFAULT_HTCP 686 bool "Htcp" if TCP_CONG_HTCP=y 687 688 config DEFAULT_HYBLA 689 bool "Hybla" if TCP_CONG_HYBLA=y 690 691 config DEFAULT_VEGAS 692 bool "Vegas" if TCP_CONG_VEGAS=y 693 694 config DEFAULT_VENO 695 bool "Veno" if TCP_CONG_VENO=y 696 697 config DEFAULT_WESTWOOD 698 bool "Westwood" if TCP_CONG_WESTWOOD=y 699 700 config DEFAULT_DCTCP 701 bool "DCTCP" if TCP_CONG_DCTCP=y 702 703 config DEFAULT_CDG 704 bool "CDG" if TCP_CONG_CDG=y 705 706 config DEFAULT_BBR 707 bool "BBR" if TCP_CONG_BBR=y 708 709 config DEFAULT_RENO 710 bool "Reno" 711 endchoice 712 713 endif 714 715 config TCP_CONG_CUBIC 716 tristate 717 depends on !TCP_CONG_ADVANCED 718 default y 719 720 config DEFAULT_TCP_CONG 721 string 722 default "bic" if DEFAULT_BIC 723 default "cubic" if DEFAULT_CUBIC 724 default "htcp" if DEFAULT_HTCP 725 default "hybla" if DEFAULT_HYBLA 726 default "vegas" if DEFAULT_VEGAS 727 default "westwood" if DEFAULT_WESTWOOD 728 default "veno" if DEFAULT_VENO 729 default "reno" if DEFAULT_RENO 730 default "dctcp" if DEFAULT_DCTCP 731 default "cdg" if DEFAULT_CDG 732 default "bbr" if DEFAULT_BBR 733 default "cubic" 734 735 config TCP_MD5SIG 736 bool "TCP: MD5 Signature Option support (RFC2385)" 737 select CRYPTO 738 select CRYPTO_MD5 739 help 740 RFC2385 specifies a method of giving MD5 protection to TCP sessions. 741 Its main (only?) use is to protect BGP sessions between core routers 742 on the Internet. 743 744 If unsure, say N. 745