1# 2# IP configuration 3# 4config 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 14config 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 55config 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 62config 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 are interested in this, please see the preliminary 74 documentation at <http://www.compendium.com.ar/policy-routing.txt> 75 and <ftp://post.tepkom.ru/pub/vol2/Linux/docs/advanced-routing.tex>. 76 You will need supporting software from 77 <ftp://ftp.tux.org/pub/net/ip-routing/>. 78 79 If unsure, say N. 80 81config IP_ROUTE_MULTIPATH 82 bool "IP: equal cost multipath" 83 depends on IP_ADVANCED_ROUTER 84 help 85 Normally, the routing tables specify a single action to be taken in 86 a deterministic manner for a given packet. If you say Y here 87 however, it becomes possible to attach several actions to a packet 88 pattern, in effect specifying several alternative paths to travel 89 for those packets. The router considers all these paths to be of 90 equal "cost" and chooses one of them in a non-deterministic fashion 91 if a matching packet arrives. 92 93config IP_ROUTE_VERBOSE 94 bool "IP: verbose route monitoring" 95 depends on IP_ADVANCED_ROUTER 96 help 97 If you say Y here, which is recommended, then the kernel will print 98 verbose messages regarding the routing, for example warnings about 99 received packets which look strange and could be evidence of an 100 attack or a misconfigured system somewhere. The information is 101 handled by the klogd daemon which is responsible for kernel messages 102 ("man klogd"). 103 104config IP_ROUTE_CLASSID 105 bool 106 107config IP_PNP 108 bool "IP: kernel level autoconfiguration" 109 help 110 This enables automatic configuration of IP addresses of devices and 111 of the routing table during kernel boot, based on either information 112 supplied on the kernel command line or by BOOTP or RARP protocols. 113 You need to say Y only for diskless machines requiring network 114 access to boot (in which case you want to say Y to "Root file system 115 on NFS" as well), because all other machines configure the network 116 in their startup scripts. 117 118config IP_PNP_DHCP 119 bool "IP: DHCP support" 120 depends on IP_PNP 121 ---help--- 122 If you want your Linux box to mount its whole root file system (the 123 one containing the directory /) from some other computer over the 124 net via NFS and you want the IP address of your computer to be 125 discovered automatically at boot time using the DHCP protocol (a 126 special protocol designed for doing this job), say Y here. In case 127 the boot ROM of your network card was designed for booting Linux and 128 does DHCP itself, providing all necessary information on the kernel 129 command line, you can say N here. 130 131 If unsure, say Y. Note that if you want to use DHCP, a DHCP server 132 must be operating on your network. Read 133 <file:Documentation/filesystems/nfs/nfsroot.txt> for details. 134 135config IP_PNP_BOOTP 136 bool "IP: BOOTP support" 137 depends on IP_PNP 138 ---help--- 139 If you want your Linux box to mount its whole root file system (the 140 one containing the directory /) from some other computer over the 141 net via NFS and you want the IP address of your computer to be 142 discovered automatically at boot time using the BOOTP protocol (a 143 special protocol designed for doing this job), say Y here. In case 144 the boot ROM of your network card was designed for booting Linux and 145 does BOOTP itself, providing all necessary information on the kernel 146 command line, you can say N here. If unsure, say Y. Note that if you 147 want to use BOOTP, a BOOTP server must be operating on your network. 148 Read <file:Documentation/filesystems/nfs/nfsroot.txt> for details. 149 150config IP_PNP_RARP 151 bool "IP: RARP support" 152 depends on IP_PNP 153 help 154 If you want your Linux box to mount its whole root file system (the 155 one containing the directory /) from some other computer over the 156 net via NFS and you want the IP address of your computer to be 157 discovered automatically at boot time using the RARP protocol (an 158 older protocol which is being obsoleted by BOOTP and DHCP), say Y 159 here. Note that if you want to use RARP, a RARP server must be 160 operating on your network. Read 161 <file:Documentation/filesystems/nfs/nfsroot.txt> for details. 162 163config NET_IPIP 164 tristate "IP: tunneling" 165 select INET_TUNNEL 166 select NET_IP_TUNNEL 167 ---help--- 168 Tunneling means encapsulating data of one protocol type within 169 another protocol and sending it over a channel that understands the 170 encapsulating protocol. This particular tunneling driver implements 171 encapsulation of IP within IP, which sounds kind of pointless, but 172 can be useful if you want to make your (or some other) machine 173 appear on a different network than it physically is, or to use 174 mobile-IP facilities (allowing laptops to seamlessly move between 175 networks without changing their IP addresses). 176 177 Saying Y to this option will produce two modules ( = code which can 178 be inserted in and removed from the running kernel whenever you 179 want). Most people won't need this and can say N. 180 181config NET_IPGRE_DEMUX 182 tristate "IP: GRE demultiplexer" 183 help 184 This is helper module to demultiplex GRE packets on GRE version field criteria. 185 Required by ip_gre and pptp modules. 186 187config NET_IP_TUNNEL 188 tristate 189 select DST_CACHE 190 default n 191 192config 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 207config 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 216config IP_MROUTE 217 bool "IP: multicast routing" 218 depends on IP_MULTICAST 219 help 220 This is used if you want your machine to act as a router for IP 221 packets that have several destination addresses. It is needed on the 222 MBONE, a high bandwidth network on top of the Internet which carries 223 audio and video broadcasts. In order to do that, you would most 224 likely run the program mrouted. If you haven't heard about it, you 225 don't need it. 226 227config IP_MROUTE_MULTIPLE_TABLES 228 bool "IP: multicast policy routing" 229 depends on IP_MROUTE && IP_ADVANCED_ROUTER 230 select FIB_RULES 231 help 232 Normally, a multicast router runs a userspace daemon and decides 233 what to do with a multicast packet based on the source and 234 destination addresses. If you say Y here, the multicast router 235 will also be able to take interfaces and packet marks into 236 account and run multiple instances of userspace daemons 237 simultaneously, each one handling a single table. 238 239 If unsure, say N. 240 241config IP_PIMSM_V1 242 bool "IP: PIM-SM version 1 support" 243 depends on IP_MROUTE 244 help 245 Kernel side support for Sparse Mode PIM (Protocol Independent 246 Multicast) version 1. This multicast routing protocol is used widely 247 because Cisco supports it. You need special software to use it 248 (pimd-v1). Please see <http://netweb.usc.edu/pim/> for more 249 information about PIM. 250 251 Say Y if you want to use PIM-SM v1. Note that you can say N here if 252 you just want to use Dense Mode PIM. 253 254config IP_PIMSM_V2 255 bool "IP: PIM-SM version 2 support" 256 depends on IP_MROUTE 257 help 258 Kernel side support for Sparse Mode PIM version 2. In order to use 259 this, you need an experimental routing daemon supporting it (pimd or 260 gated-5). This routing protocol is not used widely, so say N unless 261 you want to play with it. 262 263config SYN_COOKIES 264 bool "IP: TCP syncookie support" 265 ---help--- 266 Normal TCP/IP networking is open to an attack known as "SYN 267 flooding". This denial-of-service attack prevents legitimate remote 268 users from being able to connect to your computer during an ongoing 269 attack and requires very little work from the attacker, who can 270 operate from anywhere on the Internet. 271 272 SYN cookies provide protection against this type of attack. If you 273 say Y here, the TCP/IP stack will use a cryptographic challenge 274 protocol known as "SYN cookies" to enable legitimate users to 275 continue to connect, even when your machine is under attack. There 276 is no need for the legitimate users to change their TCP/IP software; 277 SYN cookies work transparently to them. For technical information 278 about SYN cookies, check out <http://cr.yp.to/syncookies.html>. 279 280 If you are SYN flooded, the source address reported by the kernel is 281 likely to have been forged by the attacker; it is only reported as 282 an aid in tracing the packets to their actual source and should not 283 be taken as absolute truth. 284 285 SYN cookies may prevent correct error reporting on clients when the 286 server is really overloaded. If this happens frequently better turn 287 them off. 288 289 If you say Y here, you can disable SYN cookies at run time by 290 saying Y to "/proc file system support" and 291 "Sysctl support" below and executing the command 292 293 echo 0 > /proc/sys/net/ipv4/tcp_syncookies 294 295 after the /proc file system has been mounted. 296 297 If unsure, say N. 298 299config NET_IPVTI 300 tristate "Virtual (secure) IP: tunneling" 301 select INET_TUNNEL 302 select NET_IP_TUNNEL 303 depends on INET_XFRM_MODE_TUNNEL 304 ---help--- 305 Tunneling means encapsulating data of one protocol type within 306 another protocol and sending it over a channel that understands the 307 encapsulating protocol. This can be used with xfrm mode tunnel to give 308 the notion of a secure tunnel for IPSEC and then use routing protocol 309 on top. 310 311config NET_UDP_TUNNEL 312 tristate 313 select NET_IP_TUNNEL 314 default n 315 316config NET_FOU 317 tristate "IP: Foo (IP protocols) over UDP" 318 select XFRM 319 select NET_UDP_TUNNEL 320 ---help--- 321 Foo over UDP allows any IP protocol to be directly encapsulated 322 over UDP include tunnels (IPIP, GRE, SIT). By encapsulating in UDP 323 network mechanisms and optimizations for UDP (such as ECMP 324 and RSS) can be leveraged to provide better service. 325 326config NET_FOU_IP_TUNNELS 327 bool "IP: FOU encapsulation of IP tunnels" 328 depends on NET_IPIP || NET_IPGRE || IPV6_SIT 329 select NET_FOU 330 ---help--- 331 Allow configuration of FOU or GUE encapsulation for IP tunnels. 332 When this option is enabled IP tunnels can be configured to use 333 FOU or GUE encapsulation. 334 335config INET_AH 336 tristate "IP: AH transformation" 337 select XFRM_ALGO 338 select CRYPTO 339 select CRYPTO_HMAC 340 select CRYPTO_MD5 341 select CRYPTO_SHA1 342 ---help--- 343 Support for IPsec AH. 344 345 If unsure, say Y. 346 347config INET_ESP 348 tristate "IP: ESP transformation" 349 select XFRM_ALGO 350 select CRYPTO 351 select CRYPTO_AUTHENC 352 select CRYPTO_HMAC 353 select CRYPTO_MD5 354 select CRYPTO_CBC 355 select CRYPTO_SHA1 356 select CRYPTO_DES 357 select CRYPTO_ECHAINIV 358 ---help--- 359 Support for IPsec ESP. 360 361 If unsure, say Y. 362 363config INET_IPCOMP 364 tristate "IP: IPComp transformation" 365 select INET_XFRM_TUNNEL 366 select XFRM_IPCOMP 367 ---help--- 368 Support for IP Payload Compression Protocol (IPComp) (RFC3173), 369 typically needed for IPsec. 370 371 If unsure, say Y. 372 373config INET_XFRM_TUNNEL 374 tristate 375 select INET_TUNNEL 376 default n 377 378config INET_TUNNEL 379 tristate 380 default n 381 382config INET_XFRM_MODE_TRANSPORT 383 tristate "IP: IPsec transport mode" 384 default y 385 select XFRM 386 ---help--- 387 Support for IPsec transport mode. 388 389 If unsure, say Y. 390 391config INET_XFRM_MODE_TUNNEL 392 tristate "IP: IPsec tunnel mode" 393 default y 394 select XFRM 395 ---help--- 396 Support for IPsec tunnel mode. 397 398 If unsure, say Y. 399 400config INET_XFRM_MODE_BEET 401 tristate "IP: IPsec BEET mode" 402 default y 403 select XFRM 404 ---help--- 405 Support for IPsec BEET mode. 406 407 If unsure, say Y. 408 409config INET_DIAG 410 tristate "INET: socket monitoring interface" 411 default y 412 ---help--- 413 Support for INET (TCP, DCCP, etc) socket monitoring interface used by 414 native Linux tools such as ss. ss is included in iproute2, currently 415 downloadable at: 416 417 http://www.linuxfoundation.org/collaborate/workgroups/networking/iproute2 418 419 If unsure, say Y. 420 421config INET_TCP_DIAG 422 depends on INET_DIAG 423 def_tristate INET_DIAG 424 425config INET_UDP_DIAG 426 tristate "UDP: socket monitoring interface" 427 depends on INET_DIAG && (IPV6 || IPV6=n) 428 default n 429 ---help--- 430 Support for UDP socket monitoring interface used by the ss tool. 431 If unsure, say Y. 432 433config INET_RAW_DIAG 434 tristate "RAW: socket monitoring interface" 435 depends on INET_DIAG && (IPV6 || IPV6=n) 436 default n 437 ---help--- 438 Support for RAW socket monitoring interface used by the ss tool. 439 If unsure, say Y. 440 441config INET_DIAG_DESTROY 442 bool "INET: allow privileged process to administratively close sockets" 443 depends on INET_DIAG 444 default n 445 ---help--- 446 Provides a SOCK_DESTROY operation that allows privileged processes 447 (e.g., a connection manager or a network administration tool such as 448 ss) to close sockets opened by other processes. Closing a socket in 449 this way interrupts any blocking read/write/connect operations on 450 the socket and causes future socket calls to behave as if the socket 451 had been disconnected. 452 If unsure, say N. 453 454menuconfig TCP_CONG_ADVANCED 455 bool "TCP: advanced congestion control" 456 ---help--- 457 Support for selection of various TCP congestion control 458 modules. 459 460 Nearly all users can safely say no here, and a safe default 461 selection will be made (CUBIC with new Reno as a fallback). 462 463 If unsure, say N. 464 465if TCP_CONG_ADVANCED 466 467config TCP_CONG_BIC 468 tristate "Binary Increase Congestion (BIC) control" 469 default m 470 ---help--- 471 BIC-TCP is a sender-side only change that ensures a linear RTT 472 fairness under large windows while offering both scalability and 473 bounded TCP-friendliness. The protocol combines two schemes 474 called additive increase and binary search increase. When the 475 congestion window is large, additive increase with a large 476 increment ensures linear RTT fairness as well as good 477 scalability. Under small congestion windows, binary search 478 increase provides TCP friendliness. 479 See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/ 480 481config TCP_CONG_CUBIC 482 tristate "CUBIC TCP" 483 default y 484 ---help--- 485 This is version 2.0 of BIC-TCP which uses a cubic growth function 486 among other techniques. 487 See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/cubic-paper.pdf 488 489config TCP_CONG_WESTWOOD 490 tristate "TCP Westwood+" 491 default m 492 ---help--- 493 TCP Westwood+ is a sender-side only modification of the TCP Reno 494 protocol stack that optimizes the performance of TCP congestion 495 control. It is based on end-to-end bandwidth estimation to set 496 congestion window and slow start threshold after a congestion 497 episode. Using this estimation, TCP Westwood+ adaptively sets a 498 slow start threshold and a congestion window which takes into 499 account the bandwidth used at the time congestion is experienced. 500 TCP Westwood+ significantly increases fairness wrt TCP Reno in 501 wired networks and throughput over wireless links. 502 503config TCP_CONG_HTCP 504 tristate "H-TCP" 505 default m 506 ---help--- 507 H-TCP is a send-side only modifications of the TCP Reno 508 protocol stack that optimizes the performance of TCP 509 congestion control for high speed network links. It uses a 510 modeswitch to change the alpha and beta parameters of TCP Reno 511 based on network conditions and in a way so as to be fair with 512 other Reno and H-TCP flows. 513 514config TCP_CONG_HSTCP 515 tristate "High Speed TCP" 516 default n 517 ---help--- 518 Sally Floyd's High Speed TCP (RFC 3649) congestion control. 519 A modification to TCP's congestion control mechanism for use 520 with large congestion windows. A table indicates how much to 521 increase the congestion window by when an ACK is received. 522 For more detail see http://www.icir.org/floyd/hstcp.html 523 524config TCP_CONG_HYBLA 525 tristate "TCP-Hybla congestion control algorithm" 526 default n 527 ---help--- 528 TCP-Hybla is a sender-side only change that eliminates penalization of 529 long-RTT, large-bandwidth connections, like when satellite legs are 530 involved, especially when sharing a common bottleneck with normal 531 terrestrial connections. 532 533config TCP_CONG_VEGAS 534 tristate "TCP Vegas" 535 default n 536 ---help--- 537 TCP Vegas is a sender-side only change to TCP that anticipates 538 the onset of congestion by estimating the bandwidth. TCP Vegas 539 adjusts the sending rate by modifying the congestion 540 window. TCP Vegas should provide less packet loss, but it is 541 not as aggressive as TCP Reno. 542 543config TCP_CONG_NV 544 tristate "TCP NV" 545 default n 546 ---help--- 547 TCP NV is a follow up to TCP Vegas. It has been modified to deal with 548 10G networks, measurement noise introduced by LRO, GRO and interrupt 549 coalescence. In addition, it will decrease its cwnd multiplicatively 550 instead of linearly. 551 552 Note that in general congestion avoidance (cwnd decreased when # packets 553 queued grows) cannot coexist with congestion control (cwnd decreased only 554 when there is packet loss) due to fairness issues. One scenario when they 555 can coexist safely is when the CA flows have RTTs << CC flows RTTs. 556 557 For further details see http://www.brakmo.org/networking/tcp-nv/ 558 559config TCP_CONG_SCALABLE 560 tristate "Scalable TCP" 561 default n 562 ---help--- 563 Scalable TCP is a sender-side only change to TCP which uses a 564 MIMD congestion control algorithm which has some nice scaling 565 properties, though is known to have fairness issues. 566 See http://www.deneholme.net/tom/scalable/ 567 568config TCP_CONG_LP 569 tristate "TCP Low Priority" 570 default n 571 ---help--- 572 TCP Low Priority (TCP-LP), a distributed algorithm whose goal is 573 to utilize only the excess network bandwidth as compared to the 574 ``fair share`` of bandwidth as targeted by TCP. 575 See http://www-ece.rice.edu/networks/TCP-LP/ 576 577config TCP_CONG_VENO 578 tristate "TCP Veno" 579 default n 580 ---help--- 581 TCP Veno is a sender-side only enhancement of TCP to obtain better 582 throughput over wireless networks. TCP Veno makes use of state 583 distinguishing to circumvent the difficult judgment of the packet loss 584 type. TCP Veno cuts down less congestion window in response to random 585 loss packets. 586 See <http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=1177186> 587 588config TCP_CONG_YEAH 589 tristate "YeAH TCP" 590 select TCP_CONG_VEGAS 591 default n 592 ---help--- 593 YeAH-TCP is a sender-side high-speed enabled TCP congestion control 594 algorithm, which uses a mixed loss/delay approach to compute the 595 congestion window. It's design goals target high efficiency, 596 internal, RTT and Reno fairness, resilience to link loss while 597 keeping network elements load as low as possible. 598 599 For further details look here: 600 http://wil.cs.caltech.edu/pfldnet2007/paper/YeAH_TCP.pdf 601 602config TCP_CONG_ILLINOIS 603 tristate "TCP Illinois" 604 default n 605 ---help--- 606 TCP-Illinois is a sender-side modification of TCP Reno for 607 high speed long delay links. It uses round-trip-time to 608 adjust the alpha and beta parameters to achieve a higher average 609 throughput and maintain fairness. 610 611 For further details see: 612 http://www.ews.uiuc.edu/~shaoliu/tcpillinois/index.html 613 614config TCP_CONG_DCTCP 615 tristate "DataCenter TCP (DCTCP)" 616 default n 617 ---help--- 618 DCTCP leverages Explicit Congestion Notification (ECN) in the network to 619 provide multi-bit feedback to the end hosts. It is designed to provide: 620 621 - High burst tolerance (incast due to partition/aggregate), 622 - Low latency (short flows, queries), 623 - High throughput (continuous data updates, large file transfers) with 624 commodity, shallow-buffered switches. 625 626 All switches in the data center network running DCTCP must support 627 ECN marking and be configured for marking when reaching defined switch 628 buffer thresholds. The default ECN marking threshold heuristic for 629 DCTCP on switches is 20 packets (30KB) at 1Gbps, and 65 packets 630 (~100KB) at 10Gbps, but might need further careful tweaking. 631 632 For further details see: 633 http://simula.stanford.edu/~alizade/Site/DCTCP_files/dctcp-final.pdf 634 635config TCP_CONG_CDG 636 tristate "CAIA Delay-Gradient (CDG)" 637 default n 638 ---help--- 639 CAIA Delay-Gradient (CDG) is a TCP congestion control that modifies 640 the TCP sender in order to: 641 642 o Use the delay gradient as a congestion signal. 643 o Back off with an average probability that is independent of the RTT. 644 o Coexist with flows that use loss-based congestion control. 645 o Tolerate packet loss unrelated to congestion. 646 647 For further details see: 648 D.A. Hayes and G. Armitage. "Revisiting TCP congestion control using 649 delay gradients." In Networking 2011. Preprint: http://goo.gl/No3vdg 650 651config TCP_CONG_BBR 652 tristate "BBR TCP" 653 default n 654 ---help--- 655 656 BBR (Bottleneck Bandwidth and RTT) TCP congestion control aims to 657 maximize network utilization and minimize queues. It builds an explicit 658 model of the the bottleneck delivery rate and path round-trip 659 propagation delay. It tolerates packet loss and delay unrelated to 660 congestion. It can operate over LAN, WAN, cellular, wifi, or cable 661 modem links. It can coexist with flows that use loss-based congestion 662 control, and can operate with shallow buffers, deep buffers, 663 bufferbloat, policers, or AQM schemes that do not provide a delay 664 signal. It requires the fq ("Fair Queue") pacing packet scheduler. 665 666choice 667 prompt "Default TCP congestion control" 668 default DEFAULT_CUBIC 669 help 670 Select the TCP congestion control that will be used by default 671 for all connections. 672 673 config DEFAULT_BIC 674 bool "Bic" if TCP_CONG_BIC=y 675 676 config DEFAULT_CUBIC 677 bool "Cubic" if TCP_CONG_CUBIC=y 678 679 config DEFAULT_HTCP 680 bool "Htcp" if TCP_CONG_HTCP=y 681 682 config DEFAULT_HYBLA 683 bool "Hybla" if TCP_CONG_HYBLA=y 684 685 config DEFAULT_VEGAS 686 bool "Vegas" if TCP_CONG_VEGAS=y 687 688 config DEFAULT_VENO 689 bool "Veno" if TCP_CONG_VENO=y 690 691 config DEFAULT_WESTWOOD 692 bool "Westwood" if TCP_CONG_WESTWOOD=y 693 694 config DEFAULT_DCTCP 695 bool "DCTCP" if TCP_CONG_DCTCP=y 696 697 config DEFAULT_CDG 698 bool "CDG" if TCP_CONG_CDG=y 699 700 config DEFAULT_BBR 701 bool "BBR" if TCP_CONG_BBR=y 702 703 config DEFAULT_RENO 704 bool "Reno" 705endchoice 706 707endif 708 709config TCP_CONG_CUBIC 710 tristate 711 depends on !TCP_CONG_ADVANCED 712 default y 713 714config DEFAULT_TCP_CONG 715 string 716 default "bic" if DEFAULT_BIC 717 default "cubic" if DEFAULT_CUBIC 718 default "htcp" if DEFAULT_HTCP 719 default "hybla" if DEFAULT_HYBLA 720 default "vegas" if DEFAULT_VEGAS 721 default "westwood" if DEFAULT_WESTWOOD 722 default "veno" if DEFAULT_VENO 723 default "reno" if DEFAULT_RENO 724 default "dctcp" if DEFAULT_DCTCP 725 default "cdg" if DEFAULT_CDG 726 default "bbr" if DEFAULT_BBR 727 default "cubic" 728 729config TCP_MD5SIG 730 bool "TCP: MD5 Signature Option support (RFC2385)" 731 select CRYPTO 732 select CRYPTO_MD5 733 ---help--- 734 RFC2385 specifies a method of giving MD5 protection to TCP sessions. 735 Its main (only?) use is to protect BGP sessions between core routers 736 on the Internet. 737 738 If unsure, say N. 739