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_ESP_OFFLOAD 364 tristate "IP: ESP transformation offload" 365 depends on INET_ESP 366 select XFRM_OFFLOAD 367 default n 368 ---help--- 369 Support for ESP transformation offload. This makes sense 370 only if this system really does IPsec and want to do it 371 with high throughput. A typical desktop system does not 372 need it, even if it does IPsec. 373 374 If unsure, say N. 375 376config INET_IPCOMP 377 tristate "IP: IPComp transformation" 378 select INET_XFRM_TUNNEL 379 select XFRM_IPCOMP 380 ---help--- 381 Support for IP Payload Compression Protocol (IPComp) (RFC3173), 382 typically needed for IPsec. 383 384 If unsure, say Y. 385 386config INET_XFRM_TUNNEL 387 tristate 388 select INET_TUNNEL 389 default n 390 391config INET_TUNNEL 392 tristate 393 default n 394 395config INET_XFRM_MODE_TRANSPORT 396 tristate "IP: IPsec transport mode" 397 default y 398 select XFRM 399 ---help--- 400 Support for IPsec transport mode. 401 402 If unsure, say Y. 403 404config INET_XFRM_MODE_TUNNEL 405 tristate "IP: IPsec tunnel mode" 406 default y 407 select XFRM 408 ---help--- 409 Support for IPsec tunnel mode. 410 411 If unsure, say Y. 412 413config INET_XFRM_MODE_BEET 414 tristate "IP: IPsec BEET mode" 415 default y 416 select XFRM 417 ---help--- 418 Support for IPsec BEET mode. 419 420 If unsure, say Y. 421 422config INET_DIAG 423 tristate "INET: socket monitoring interface" 424 default y 425 ---help--- 426 Support for INET (TCP, DCCP, etc) socket monitoring interface used by 427 native Linux tools such as ss. ss is included in iproute2, currently 428 downloadable at: 429 430 http://www.linuxfoundation.org/collaborate/workgroups/networking/iproute2 431 432 If unsure, say Y. 433 434config INET_TCP_DIAG 435 depends on INET_DIAG 436 def_tristate INET_DIAG 437 438config INET_UDP_DIAG 439 tristate "UDP: socket monitoring interface" 440 depends on INET_DIAG && (IPV6 || IPV6=n) 441 default n 442 ---help--- 443 Support for UDP socket monitoring interface used by the ss tool. 444 If unsure, say Y. 445 446config INET_RAW_DIAG 447 tristate "RAW: socket monitoring interface" 448 depends on INET_DIAG && (IPV6 || IPV6=n) 449 default n 450 ---help--- 451 Support for RAW socket monitoring interface used by the ss tool. 452 If unsure, say Y. 453 454config INET_DIAG_DESTROY 455 bool "INET: allow privileged process to administratively close sockets" 456 depends on INET_DIAG 457 default n 458 ---help--- 459 Provides a SOCK_DESTROY operation that allows privileged processes 460 (e.g., a connection manager or a network administration tool such as 461 ss) to close sockets opened by other processes. Closing a socket in 462 this way interrupts any blocking read/write/connect operations on 463 the socket and causes future socket calls to behave as if the socket 464 had been disconnected. 465 If unsure, say N. 466 467menuconfig TCP_CONG_ADVANCED 468 bool "TCP: advanced congestion control" 469 ---help--- 470 Support for selection of various TCP congestion control 471 modules. 472 473 Nearly all users can safely say no here, and a safe default 474 selection will be made (CUBIC with new Reno as a fallback). 475 476 If unsure, say N. 477 478if TCP_CONG_ADVANCED 479 480config TCP_CONG_BIC 481 tristate "Binary Increase Congestion (BIC) control" 482 default m 483 ---help--- 484 BIC-TCP is a sender-side only change that ensures a linear RTT 485 fairness under large windows while offering both scalability and 486 bounded TCP-friendliness. The protocol combines two schemes 487 called additive increase and binary search increase. When the 488 congestion window is large, additive increase with a large 489 increment ensures linear RTT fairness as well as good 490 scalability. Under small congestion windows, binary search 491 increase provides TCP friendliness. 492 See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/ 493 494config TCP_CONG_CUBIC 495 tristate "CUBIC TCP" 496 default y 497 ---help--- 498 This is version 2.0 of BIC-TCP which uses a cubic growth function 499 among other techniques. 500 See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/cubic-paper.pdf 501 502config TCP_CONG_WESTWOOD 503 tristate "TCP Westwood+" 504 default m 505 ---help--- 506 TCP Westwood+ is a sender-side only modification of the TCP Reno 507 protocol stack that optimizes the performance of TCP congestion 508 control. It is based on end-to-end bandwidth estimation to set 509 congestion window and slow start threshold after a congestion 510 episode. Using this estimation, TCP Westwood+ adaptively sets a 511 slow start threshold and a congestion window which takes into 512 account the bandwidth used at the time congestion is experienced. 513 TCP Westwood+ significantly increases fairness wrt TCP Reno in 514 wired networks and throughput over wireless links. 515 516config TCP_CONG_HTCP 517 tristate "H-TCP" 518 default m 519 ---help--- 520 H-TCP is a send-side only modifications of the TCP Reno 521 protocol stack that optimizes the performance of TCP 522 congestion control for high speed network links. It uses a 523 modeswitch to change the alpha and beta parameters of TCP Reno 524 based on network conditions and in a way so as to be fair with 525 other Reno and H-TCP flows. 526 527config TCP_CONG_HSTCP 528 tristate "High Speed TCP" 529 default n 530 ---help--- 531 Sally Floyd's High Speed TCP (RFC 3649) congestion control. 532 A modification to TCP's congestion control mechanism for use 533 with large congestion windows. A table indicates how much to 534 increase the congestion window by when an ACK is received. 535 For more detail see http://www.icir.org/floyd/hstcp.html 536 537config TCP_CONG_HYBLA 538 tristate "TCP-Hybla congestion control algorithm" 539 default n 540 ---help--- 541 TCP-Hybla is a sender-side only change that eliminates penalization of 542 long-RTT, large-bandwidth connections, like when satellite legs are 543 involved, especially when sharing a common bottleneck with normal 544 terrestrial connections. 545 546config TCP_CONG_VEGAS 547 tristate "TCP Vegas" 548 default n 549 ---help--- 550 TCP Vegas is a sender-side only change to TCP that anticipates 551 the onset of congestion by estimating the bandwidth. TCP Vegas 552 adjusts the sending rate by modifying the congestion 553 window. TCP Vegas should provide less packet loss, but it is 554 not as aggressive as TCP Reno. 555 556config TCP_CONG_NV 557 tristate "TCP NV" 558 default n 559 ---help--- 560 TCP NV is a follow up to TCP Vegas. It has been modified to deal with 561 10G networks, measurement noise introduced by LRO, GRO and interrupt 562 coalescence. In addition, it will decrease its cwnd multiplicatively 563 instead of linearly. 564 565 Note that in general congestion avoidance (cwnd decreased when # packets 566 queued grows) cannot coexist with congestion control (cwnd decreased only 567 when there is packet loss) due to fairness issues. One scenario when they 568 can coexist safely is when the CA flows have RTTs << CC flows RTTs. 569 570 For further details see http://www.brakmo.org/networking/tcp-nv/ 571 572config TCP_CONG_SCALABLE 573 tristate "Scalable TCP" 574 default n 575 ---help--- 576 Scalable TCP is a sender-side only change to TCP which uses a 577 MIMD congestion control algorithm which has some nice scaling 578 properties, though is known to have fairness issues. 579 See http://www.deneholme.net/tom/scalable/ 580 581config TCP_CONG_LP 582 tristate "TCP Low Priority" 583 default n 584 ---help--- 585 TCP Low Priority (TCP-LP), a distributed algorithm whose goal is 586 to utilize only the excess network bandwidth as compared to the 587 ``fair share`` of bandwidth as targeted by TCP. 588 See http://www-ece.rice.edu/networks/TCP-LP/ 589 590config TCP_CONG_VENO 591 tristate "TCP Veno" 592 default n 593 ---help--- 594 TCP Veno is a sender-side only enhancement of TCP to obtain better 595 throughput over wireless networks. TCP Veno makes use of state 596 distinguishing to circumvent the difficult judgment of the packet loss 597 type. TCP Veno cuts down less congestion window in response to random 598 loss packets. 599 See <http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=1177186> 600 601config TCP_CONG_YEAH 602 tristate "YeAH TCP" 603 select TCP_CONG_VEGAS 604 default n 605 ---help--- 606 YeAH-TCP is a sender-side high-speed enabled TCP congestion control 607 algorithm, which uses a mixed loss/delay approach to compute the 608 congestion window. It's design goals target high efficiency, 609 internal, RTT and Reno fairness, resilience to link loss while 610 keeping network elements load as low as possible. 611 612 For further details look here: 613 http://wil.cs.caltech.edu/pfldnet2007/paper/YeAH_TCP.pdf 614 615config TCP_CONG_ILLINOIS 616 tristate "TCP Illinois" 617 default n 618 ---help--- 619 TCP-Illinois is a sender-side modification of TCP Reno for 620 high speed long delay links. It uses round-trip-time to 621 adjust the alpha and beta parameters to achieve a higher average 622 throughput and maintain fairness. 623 624 For further details see: 625 http://www.ews.uiuc.edu/~shaoliu/tcpillinois/index.html 626 627config TCP_CONG_DCTCP 628 tristate "DataCenter TCP (DCTCP)" 629 default n 630 ---help--- 631 DCTCP leverages Explicit Congestion Notification (ECN) in the network to 632 provide multi-bit feedback to the end hosts. It is designed to provide: 633 634 - High burst tolerance (incast due to partition/aggregate), 635 - Low latency (short flows, queries), 636 - High throughput (continuous data updates, large file transfers) with 637 commodity, shallow-buffered switches. 638 639 All switches in the data center network running DCTCP must support 640 ECN marking and be configured for marking when reaching defined switch 641 buffer thresholds. The default ECN marking threshold heuristic for 642 DCTCP on switches is 20 packets (30KB) at 1Gbps, and 65 packets 643 (~100KB) at 10Gbps, but might need further careful tweaking. 644 645 For further details see: 646 http://simula.stanford.edu/~alizade/Site/DCTCP_files/dctcp-final.pdf 647 648config TCP_CONG_CDG 649 tristate "CAIA Delay-Gradient (CDG)" 650 default n 651 ---help--- 652 CAIA Delay-Gradient (CDG) is a TCP congestion control that modifies 653 the TCP sender in order to: 654 655 o Use the delay gradient as a congestion signal. 656 o Back off with an average probability that is independent of the RTT. 657 o Coexist with flows that use loss-based congestion control. 658 o Tolerate packet loss unrelated to congestion. 659 660 For further details see: 661 D.A. Hayes and G. Armitage. "Revisiting TCP congestion control using 662 delay gradients." In Networking 2011. Preprint: http://goo.gl/No3vdg 663 664config TCP_CONG_BBR 665 tristate "BBR TCP" 666 default n 667 ---help--- 668 669 BBR (Bottleneck Bandwidth and RTT) TCP congestion control aims to 670 maximize network utilization and minimize queues. It builds an explicit 671 model of the the bottleneck delivery rate and path round-trip 672 propagation delay. It tolerates packet loss and delay unrelated to 673 congestion. It can operate over LAN, WAN, cellular, wifi, or cable 674 modem links. It can coexist with flows that use loss-based congestion 675 control, and can operate with shallow buffers, deep buffers, 676 bufferbloat, policers, or AQM schemes that do not provide a delay 677 signal. It requires the fq ("Fair Queue") pacing packet scheduler. 678 679choice 680 prompt "Default TCP congestion control" 681 default DEFAULT_CUBIC 682 help 683 Select the TCP congestion control that will be used by default 684 for all connections. 685 686 config DEFAULT_BIC 687 bool "Bic" if TCP_CONG_BIC=y 688 689 config DEFAULT_CUBIC 690 bool "Cubic" if TCP_CONG_CUBIC=y 691 692 config DEFAULT_HTCP 693 bool "Htcp" if TCP_CONG_HTCP=y 694 695 config DEFAULT_HYBLA 696 bool "Hybla" if TCP_CONG_HYBLA=y 697 698 config DEFAULT_VEGAS 699 bool "Vegas" if TCP_CONG_VEGAS=y 700 701 config DEFAULT_VENO 702 bool "Veno" if TCP_CONG_VENO=y 703 704 config DEFAULT_WESTWOOD 705 bool "Westwood" if TCP_CONG_WESTWOOD=y 706 707 config DEFAULT_DCTCP 708 bool "DCTCP" if TCP_CONG_DCTCP=y 709 710 config DEFAULT_CDG 711 bool "CDG" if TCP_CONG_CDG=y 712 713 config DEFAULT_BBR 714 bool "BBR" if TCP_CONG_BBR=y 715 716 config DEFAULT_RENO 717 bool "Reno" 718endchoice 719 720endif 721 722config TCP_CONG_CUBIC 723 tristate 724 depends on !TCP_CONG_ADVANCED 725 default y 726 727config DEFAULT_TCP_CONG 728 string 729 default "bic" if DEFAULT_BIC 730 default "cubic" if DEFAULT_CUBIC 731 default "htcp" if DEFAULT_HTCP 732 default "hybla" if DEFAULT_HYBLA 733 default "vegas" if DEFAULT_VEGAS 734 default "westwood" if DEFAULT_WESTWOOD 735 default "veno" if DEFAULT_VENO 736 default "reno" if DEFAULT_RENO 737 default "dctcp" if DEFAULT_DCTCP 738 default "cdg" if DEFAULT_CDG 739 default "bbr" if DEFAULT_BBR 740 default "cubic" 741 742config TCP_MD5SIG 743 bool "TCP: MD5 Signature Option support (RFC2385)" 744 select CRYPTO 745 select CRYPTO_MD5 746 ---help--- 747 RFC2385 specifies a method of giving MD5 protection to TCP sessions. 748 Its main (only?) use is to protect BGP sessions between core routers 749 on the Internet. 750 751 If unsure, say N. 752