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 need more information, see the Linux Advanced 74 Routing and Traffic Control documentation at 75 <http://lartc.org/howto/lartc.rpdb.html> 76 77 If unsure, say N. 78 79config IP_ROUTE_MULTIPATH 80 bool "IP: equal cost multipath" 81 depends on IP_ADVANCED_ROUTER 82 help 83 Normally, the routing tables specify a single action to be taken in 84 a deterministic manner for a given packet. If you say Y here 85 however, it becomes possible to attach several actions to a packet 86 pattern, in effect specifying several alternative paths to travel 87 for those packets. The router considers all these paths to be of 88 equal "cost" and chooses one of them in a non-deterministic fashion 89 if a matching packet arrives. 90 91config IP_ROUTE_VERBOSE 92 bool "IP: verbose route monitoring" 93 depends on IP_ADVANCED_ROUTER 94 help 95 If you say Y here, which is recommended, then the kernel will print 96 verbose messages regarding the routing, for example warnings about 97 received packets which look strange and could be evidence of an 98 attack or a misconfigured system somewhere. The information is 99 handled by the klogd daemon which is responsible for kernel messages 100 ("man klogd"). 101 102config IP_ROUTE_CLASSID 103 bool 104 105config IP_PNP 106 bool "IP: kernel level autoconfiguration" 107 help 108 This enables automatic configuration of IP addresses of devices and 109 of the routing table during kernel boot, based on either information 110 supplied on the kernel command line or by BOOTP or RARP protocols. 111 You need to say Y only for diskless machines requiring network 112 access to boot (in which case you want to say Y to "Root file system 113 on NFS" as well), because all other machines configure the network 114 in their startup scripts. 115 116config IP_PNP_DHCP 117 bool "IP: DHCP support" 118 depends on IP_PNP 119 ---help--- 120 If you want your Linux box to mount its whole root file system (the 121 one containing the directory /) from some other computer over the 122 net via NFS and you want the IP address of your computer to be 123 discovered automatically at boot time using the DHCP protocol (a 124 special protocol designed for doing this job), say Y here. In case 125 the boot ROM of your network card was designed for booting Linux and 126 does DHCP itself, providing all necessary information on the kernel 127 command line, you can say N here. 128 129 If unsure, say Y. Note that if you want to use DHCP, a DHCP server 130 must be operating on your network. Read 131 <file:Documentation/filesystems/nfs/nfsroot.txt> for details. 132 133config IP_PNP_BOOTP 134 bool "IP: BOOTP support" 135 depends on IP_PNP 136 ---help--- 137 If you want your Linux box to mount its whole root file system (the 138 one containing the directory /) from some other computer over the 139 net via NFS and you want the IP address of your computer to be 140 discovered automatically at boot time using the BOOTP protocol (a 141 special protocol designed for doing this job), say Y here. In case 142 the boot ROM of your network card was designed for booting Linux and 143 does BOOTP itself, providing all necessary information on the kernel 144 command line, you can say N here. If unsure, say Y. Note that if you 145 want to use BOOTP, a BOOTP server must be operating on your network. 146 Read <file:Documentation/filesystems/nfs/nfsroot.txt> for details. 147 148config IP_PNP_RARP 149 bool "IP: RARP support" 150 depends on IP_PNP 151 help 152 If you want your Linux box to mount its whole root file system (the 153 one containing the directory /) from some other computer over the 154 net via NFS and you want the IP address of your computer to be 155 discovered automatically at boot time using the RARP protocol (an 156 older protocol which is being obsoleted by BOOTP and DHCP), say Y 157 here. Note that if you want to use RARP, a RARP server must be 158 operating on your network. Read 159 <file:Documentation/filesystems/nfs/nfsroot.txt> for details. 160 161config NET_IPIP 162 tristate "IP: tunneling" 163 select INET_TUNNEL 164 select NET_IP_TUNNEL 165 ---help--- 166 Tunneling means encapsulating data of one protocol type within 167 another protocol and sending it over a channel that understands the 168 encapsulating protocol. This particular tunneling driver implements 169 encapsulation of IP within IP, which sounds kind of pointless, but 170 can be useful if you want to make your (or some other) machine 171 appear on a different network than it physically is, or to use 172 mobile-IP facilities (allowing laptops to seamlessly move between 173 networks without changing their IP addresses). 174 175 Saying Y to this option will produce two modules ( = code which can 176 be inserted in and removed from the running kernel whenever you 177 want). Most people won't need this and can say N. 178 179config NET_IPGRE_DEMUX 180 tristate "IP: GRE demultiplexer" 181 help 182 This is helper module to demultiplex GRE packets on GRE version field criteria. 183 Required by ip_gre and pptp modules. 184 185config NET_IP_TUNNEL 186 tristate 187 select DST_CACHE 188 select GRO_CELLS 189 default n 190 191config NET_IPGRE 192 tristate "IP: GRE tunnels over IP" 193 depends on (IPV6 || IPV6=n) && NET_IPGRE_DEMUX 194 select NET_IP_TUNNEL 195 help 196 Tunneling means encapsulating data of one protocol type within 197 another protocol and sending it over a channel that understands the 198 encapsulating protocol. This particular tunneling driver implements 199 GRE (Generic Routing Encapsulation) and at this time allows 200 encapsulating of IPv4 or IPv6 over existing IPv4 infrastructure. 201 This driver is useful if the other endpoint is a Cisco router: Cisco 202 likes GRE much better than the other Linux tunneling driver ("IP 203 tunneling" above). In addition, GRE allows multicast redistribution 204 through the tunnel. 205 206config NET_IPGRE_BROADCAST 207 bool "IP: broadcast GRE over IP" 208 depends on IP_MULTICAST && NET_IPGRE 209 help 210 One application of GRE/IP is to construct a broadcast WAN (Wide Area 211 Network), which looks like a normal Ethernet LAN (Local Area 212 Network), but can be distributed all over the Internet. If you want 213 to do that, say Y here and to "IP multicast routing" below. 214 215config IP_MROUTE 216 bool "IP: multicast routing" 217 depends on IP_MULTICAST 218 help 219 This is used if you want your machine to act as a router for IP 220 packets that have several destination addresses. It is needed on the 221 MBONE, a high bandwidth network on top of the Internet which carries 222 audio and video broadcasts. In order to do that, you would most 223 likely run the program mrouted. If you haven't heard about it, you 224 don't need it. 225 226config IP_MROUTE_MULTIPLE_TABLES 227 bool "IP: multicast policy routing" 228 depends on IP_MROUTE && IP_ADVANCED_ROUTER 229 select FIB_RULES 230 help 231 Normally, a multicast router runs a userspace daemon and decides 232 what to do with a multicast packet based on the source and 233 destination addresses. If you say Y here, the multicast router 234 will also be able to take interfaces and packet marks into 235 account and run multiple instances of userspace daemons 236 simultaneously, each one handling a single table. 237 238 If unsure, say N. 239 240config IP_PIMSM_V1 241 bool "IP: PIM-SM version 1 support" 242 depends on IP_MROUTE 243 help 244 Kernel side support for Sparse Mode PIM (Protocol Independent 245 Multicast) version 1. This multicast routing protocol is used widely 246 because Cisco supports it. You need special software to use it 247 (pimd-v1). Please see <http://netweb.usc.edu/pim/> for more 248 information about PIM. 249 250 Say Y if you want to use PIM-SM v1. Note that you can say N here if 251 you just want to use Dense Mode PIM. 252 253config IP_PIMSM_V2 254 bool "IP: PIM-SM version 2 support" 255 depends on IP_MROUTE 256 help 257 Kernel side support for Sparse Mode PIM version 2. In order to use 258 this, you need an experimental routing daemon supporting it (pimd or 259 gated-5). This routing protocol is not used widely, so say N unless 260 you want to play with it. 261 262config SYN_COOKIES 263 bool "IP: TCP syncookie support" 264 ---help--- 265 Normal TCP/IP networking is open to an attack known as "SYN 266 flooding". This denial-of-service attack prevents legitimate remote 267 users from being able to connect to your computer during an ongoing 268 attack and requires very little work from the attacker, who can 269 operate from anywhere on the Internet. 270 271 SYN cookies provide protection against this type of attack. If you 272 say Y here, the TCP/IP stack will use a cryptographic challenge 273 protocol known as "SYN cookies" to enable legitimate users to 274 continue to connect, even when your machine is under attack. There 275 is no need for the legitimate users to change their TCP/IP software; 276 SYN cookies work transparently to them. For technical information 277 about SYN cookies, check out <http://cr.yp.to/syncookies.html>. 278 279 If you are SYN flooded, the source address reported by the kernel is 280 likely to have been forged by the attacker; it is only reported as 281 an aid in tracing the packets to their actual source and should not 282 be taken as absolute truth. 283 284 SYN cookies may prevent correct error reporting on clients when the 285 server is really overloaded. If this happens frequently better turn 286 them off. 287 288 If you say Y here, you can disable SYN cookies at run time by 289 saying Y to "/proc file system support" and 290 "Sysctl support" below and executing the command 291 292 echo 0 > /proc/sys/net/ipv4/tcp_syncookies 293 294 after the /proc file system has been mounted. 295 296 If unsure, say N. 297 298config NET_IPVTI 299 tristate "Virtual (secure) IP: tunneling" 300 select INET_TUNNEL 301 select NET_IP_TUNNEL 302 depends on INET_XFRM_MODE_TUNNEL 303 ---help--- 304 Tunneling means encapsulating data of one protocol type within 305 another protocol and sending it over a channel that understands the 306 encapsulating protocol. This can be used with xfrm mode tunnel to give 307 the notion of a secure tunnel for IPSEC and then use routing protocol 308 on top. 309 310config NET_UDP_TUNNEL 311 tristate 312 select NET_IP_TUNNEL 313 default n 314 315config NET_FOU 316 tristate "IP: Foo (IP protocols) over UDP" 317 select XFRM 318 select NET_UDP_TUNNEL 319 ---help--- 320 Foo over UDP allows any IP protocol to be directly encapsulated 321 over UDP include tunnels (IPIP, GRE, SIT). By encapsulating in UDP 322 network mechanisms and optimizations for UDP (such as ECMP 323 and RSS) can be leveraged to provide better service. 324 325config NET_FOU_IP_TUNNELS 326 bool "IP: FOU encapsulation of IP tunnels" 327 depends on NET_IPIP || NET_IPGRE || IPV6_SIT 328 select NET_FOU 329 ---help--- 330 Allow configuration of FOU or GUE encapsulation for IP tunnels. 331 When this option is enabled IP tunnels can be configured to use 332 FOU or GUE encapsulation. 333 334config INET_AH 335 tristate "IP: AH transformation" 336 select XFRM_ALGO 337 select CRYPTO 338 select CRYPTO_HMAC 339 select CRYPTO_MD5 340 select CRYPTO_SHA1 341 ---help--- 342 Support for IPsec AH. 343 344 If unsure, say Y. 345 346config INET_ESP 347 tristate "IP: ESP transformation" 348 select XFRM_ALGO 349 select CRYPTO 350 select CRYPTO_AUTHENC 351 select CRYPTO_HMAC 352 select CRYPTO_MD5 353 select CRYPTO_CBC 354 select CRYPTO_SHA1 355 select CRYPTO_DES 356 select CRYPTO_ECHAINIV 357 ---help--- 358 Support for IPsec ESP. 359 360 If unsure, say Y. 361 362config INET_ESP_OFFLOAD 363 tristate "IP: ESP transformation offload" 364 depends on INET_ESP 365 select XFRM_OFFLOAD 366 default n 367 ---help--- 368 Support for ESP transformation offload. This makes sense 369 only if this system really does IPsec and want to do it 370 with high throughput. A typical desktop system does not 371 need it, even if it does IPsec. 372 373 If unsure, say N. 374 375config INET_IPCOMP 376 tristate "IP: IPComp transformation" 377 select INET_XFRM_TUNNEL 378 select XFRM_IPCOMP 379 ---help--- 380 Support for IP Payload Compression Protocol (IPComp) (RFC3173), 381 typically needed for IPsec. 382 383 If unsure, say Y. 384 385config INET_XFRM_TUNNEL 386 tristate 387 select INET_TUNNEL 388 default n 389 390config INET_TUNNEL 391 tristate 392 default n 393 394config INET_XFRM_MODE_TRANSPORT 395 tristate "IP: IPsec transport mode" 396 default y 397 select XFRM 398 ---help--- 399 Support for IPsec transport mode. 400 401 If unsure, say Y. 402 403config INET_XFRM_MODE_TUNNEL 404 tristate "IP: IPsec tunnel mode" 405 default y 406 select XFRM 407 ---help--- 408 Support for IPsec tunnel mode. 409 410 If unsure, say Y. 411 412config INET_XFRM_MODE_BEET 413 tristate "IP: IPsec BEET mode" 414 default y 415 select XFRM 416 ---help--- 417 Support for IPsec BEET mode. 418 419 If unsure, say Y. 420 421config INET_DIAG 422 tristate "INET: socket monitoring interface" 423 default y 424 ---help--- 425 Support for INET (TCP, DCCP, etc) socket monitoring interface used by 426 native Linux tools such as ss. ss is included in iproute2, currently 427 downloadable at: 428 429 http://www.linuxfoundation.org/collaborate/workgroups/networking/iproute2 430 431 If unsure, say Y. 432 433config INET_TCP_DIAG 434 depends on INET_DIAG 435 def_tristate INET_DIAG 436 437config INET_UDP_DIAG 438 tristate "UDP: socket monitoring interface" 439 depends on INET_DIAG && (IPV6 || IPV6=n) 440 default n 441 ---help--- 442 Support for UDP socket monitoring interface used by the ss tool. 443 If unsure, say Y. 444 445config INET_RAW_DIAG 446 tristate "RAW: socket monitoring interface" 447 depends on INET_DIAG && (IPV6 || IPV6=n) 448 default n 449 ---help--- 450 Support for RAW socket monitoring interface used by the ss tool. 451 If unsure, say Y. 452 453config INET_DIAG_DESTROY 454 bool "INET: allow privileged process to administratively close sockets" 455 depends on INET_DIAG 456 default n 457 ---help--- 458 Provides a SOCK_DESTROY operation that allows privileged processes 459 (e.g., a connection manager or a network administration tool such as 460 ss) to close sockets opened by other processes. Closing a socket in 461 this way interrupts any blocking read/write/connect operations on 462 the socket and causes future socket calls to behave as if the socket 463 had been disconnected. 464 If unsure, say N. 465 466menuconfig TCP_CONG_ADVANCED 467 bool "TCP: advanced congestion control" 468 ---help--- 469 Support for selection of various TCP congestion control 470 modules. 471 472 Nearly all users can safely say no here, and a safe default 473 selection will be made (CUBIC with new Reno as a fallback). 474 475 If unsure, say N. 476 477if TCP_CONG_ADVANCED 478 479config TCP_CONG_BIC 480 tristate "Binary Increase Congestion (BIC) control" 481 default m 482 ---help--- 483 BIC-TCP is a sender-side only change that ensures a linear RTT 484 fairness under large windows while offering both scalability and 485 bounded TCP-friendliness. The protocol combines two schemes 486 called additive increase and binary search increase. When the 487 congestion window is large, additive increase with a large 488 increment ensures linear RTT fairness as well as good 489 scalability. Under small congestion windows, binary search 490 increase provides TCP friendliness. 491 See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/ 492 493config TCP_CONG_CUBIC 494 tristate "CUBIC TCP" 495 default y 496 ---help--- 497 This is version 2.0 of BIC-TCP which uses a cubic growth function 498 among other techniques. 499 See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/cubic-paper.pdf 500 501config TCP_CONG_WESTWOOD 502 tristate "TCP Westwood+" 503 default m 504 ---help--- 505 TCP Westwood+ is a sender-side only modification of the TCP Reno 506 protocol stack that optimizes the performance of TCP congestion 507 control. It is based on end-to-end bandwidth estimation to set 508 congestion window and slow start threshold after a congestion 509 episode. Using this estimation, TCP Westwood+ adaptively sets a 510 slow start threshold and a congestion window which takes into 511 account the bandwidth used at the time congestion is experienced. 512 TCP Westwood+ significantly increases fairness wrt TCP Reno in 513 wired networks and throughput over wireless links. 514 515config TCP_CONG_HTCP 516 tristate "H-TCP" 517 default m 518 ---help--- 519 H-TCP is a send-side only modifications of the TCP Reno 520 protocol stack that optimizes the performance of TCP 521 congestion control for high speed network links. It uses a 522 modeswitch to change the alpha and beta parameters of TCP Reno 523 based on network conditions and in a way so as to be fair with 524 other Reno and H-TCP flows. 525 526config TCP_CONG_HSTCP 527 tristate "High Speed TCP" 528 default n 529 ---help--- 530 Sally Floyd's High Speed TCP (RFC 3649) congestion control. 531 A modification to TCP's congestion control mechanism for use 532 with large congestion windows. A table indicates how much to 533 increase the congestion window by when an ACK is received. 534 For more detail see http://www.icir.org/floyd/hstcp.html 535 536config TCP_CONG_HYBLA 537 tristate "TCP-Hybla congestion control algorithm" 538 default n 539 ---help--- 540 TCP-Hybla is a sender-side only change that eliminates penalization of 541 long-RTT, large-bandwidth connections, like when satellite legs are 542 involved, especially when sharing a common bottleneck with normal 543 terrestrial connections. 544 545config TCP_CONG_VEGAS 546 tristate "TCP Vegas" 547 default n 548 ---help--- 549 TCP Vegas is a sender-side only change to TCP that anticipates 550 the onset of congestion by estimating the bandwidth. TCP Vegas 551 adjusts the sending rate by modifying the congestion 552 window. TCP Vegas should provide less packet loss, but it is 553 not as aggressive as TCP Reno. 554 555config TCP_CONG_NV 556 tristate "TCP NV" 557 default n 558 ---help--- 559 TCP NV is a follow up to TCP Vegas. It has been modified to deal with 560 10G networks, measurement noise introduced by LRO, GRO and interrupt 561 coalescence. In addition, it will decrease its cwnd multiplicatively 562 instead of linearly. 563 564 Note that in general congestion avoidance (cwnd decreased when # packets 565 queued grows) cannot coexist with congestion control (cwnd decreased only 566 when there is packet loss) due to fairness issues. One scenario when they 567 can coexist safely is when the CA flows have RTTs << CC flows RTTs. 568 569 For further details see http://www.brakmo.org/networking/tcp-nv/ 570 571config TCP_CONG_SCALABLE 572 tristate "Scalable TCP" 573 default n 574 ---help--- 575 Scalable TCP is a sender-side only change to TCP which uses a 576 MIMD congestion control algorithm which has some nice scaling 577 properties, though is known to have fairness issues. 578 See http://www.deneholme.net/tom/scalable/ 579 580config TCP_CONG_LP 581 tristate "TCP Low Priority" 582 default n 583 ---help--- 584 TCP Low Priority (TCP-LP), a distributed algorithm whose goal is 585 to utilize only the excess network bandwidth as compared to the 586 ``fair share`` of bandwidth as targeted by TCP. 587 See http://www-ece.rice.edu/networks/TCP-LP/ 588 589config TCP_CONG_VENO 590 tristate "TCP Veno" 591 default n 592 ---help--- 593 TCP Veno is a sender-side only enhancement of TCP to obtain better 594 throughput over wireless networks. TCP Veno makes use of state 595 distinguishing to circumvent the difficult judgment of the packet loss 596 type. TCP Veno cuts down less congestion window in response to random 597 loss packets. 598 See <http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=1177186> 599 600config TCP_CONG_YEAH 601 tristate "YeAH TCP" 602 select TCP_CONG_VEGAS 603 default n 604 ---help--- 605 YeAH-TCP is a sender-side high-speed enabled TCP congestion control 606 algorithm, which uses a mixed loss/delay approach to compute the 607 congestion window. It's design goals target high efficiency, 608 internal, RTT and Reno fairness, resilience to link loss while 609 keeping network elements load as low as possible. 610 611 For further details look here: 612 http://wil.cs.caltech.edu/pfldnet2007/paper/YeAH_TCP.pdf 613 614config TCP_CONG_ILLINOIS 615 tristate "TCP Illinois" 616 default n 617 ---help--- 618 TCP-Illinois is a sender-side modification of TCP Reno for 619 high speed long delay links. It uses round-trip-time to 620 adjust the alpha and beta parameters to achieve a higher average 621 throughput and maintain fairness. 622 623 For further details see: 624 http://www.ews.uiuc.edu/~shaoliu/tcpillinois/index.html 625 626config TCP_CONG_DCTCP 627 tristate "DataCenter TCP (DCTCP)" 628 default n 629 ---help--- 630 DCTCP leverages Explicit Congestion Notification (ECN) in the network to 631 provide multi-bit feedback to the end hosts. It is designed to provide: 632 633 - High burst tolerance (incast due to partition/aggregate), 634 - Low latency (short flows, queries), 635 - High throughput (continuous data updates, large file transfers) with 636 commodity, shallow-buffered switches. 637 638 All switches in the data center network running DCTCP must support 639 ECN marking and be configured for marking when reaching defined switch 640 buffer thresholds. The default ECN marking threshold heuristic for 641 DCTCP on switches is 20 packets (30KB) at 1Gbps, and 65 packets 642 (~100KB) at 10Gbps, but might need further careful tweaking. 643 644 For further details see: 645 http://simula.stanford.edu/~alizade/Site/DCTCP_files/dctcp-final.pdf 646 647config TCP_CONG_CDG 648 tristate "CAIA Delay-Gradient (CDG)" 649 default n 650 ---help--- 651 CAIA Delay-Gradient (CDG) is a TCP congestion control that modifies 652 the TCP sender in order to: 653 654 o Use the delay gradient as a congestion signal. 655 o Back off with an average probability that is independent of the RTT. 656 o Coexist with flows that use loss-based congestion control. 657 o Tolerate packet loss unrelated to congestion. 658 659 For further details see: 660 D.A. Hayes and G. Armitage. "Revisiting TCP congestion control using 661 delay gradients." In Networking 2011. Preprint: http://goo.gl/No3vdg 662 663config TCP_CONG_BBR 664 tristate "BBR TCP" 665 default n 666 ---help--- 667 668 BBR (Bottleneck Bandwidth and RTT) TCP congestion control aims to 669 maximize network utilization and minimize queues. It builds an explicit 670 model of the the bottleneck delivery rate and path round-trip 671 propagation delay. It tolerates packet loss and delay unrelated to 672 congestion. It can operate over LAN, WAN, cellular, wifi, or cable 673 modem links. It can coexist with flows that use loss-based congestion 674 control, and can operate with shallow buffers, deep buffers, 675 bufferbloat, policers, or AQM schemes that do not provide a delay 676 signal. It requires the fq ("Fair Queue") pacing packet scheduler. 677 678choice 679 prompt "Default TCP congestion control" 680 default DEFAULT_CUBIC 681 help 682 Select the TCP congestion control that will be used by default 683 for all connections. 684 685 config DEFAULT_BIC 686 bool "Bic" if TCP_CONG_BIC=y 687 688 config DEFAULT_CUBIC 689 bool "Cubic" if TCP_CONG_CUBIC=y 690 691 config DEFAULT_HTCP 692 bool "Htcp" if TCP_CONG_HTCP=y 693 694 config DEFAULT_HYBLA 695 bool "Hybla" if TCP_CONG_HYBLA=y 696 697 config DEFAULT_VEGAS 698 bool "Vegas" if TCP_CONG_VEGAS=y 699 700 config DEFAULT_VENO 701 bool "Veno" if TCP_CONG_VENO=y 702 703 config DEFAULT_WESTWOOD 704 bool "Westwood" if TCP_CONG_WESTWOOD=y 705 706 config DEFAULT_DCTCP 707 bool "DCTCP" if TCP_CONG_DCTCP=y 708 709 config DEFAULT_CDG 710 bool "CDG" if TCP_CONG_CDG=y 711 712 config DEFAULT_BBR 713 bool "BBR" if TCP_CONG_BBR=y 714 715 config DEFAULT_RENO 716 bool "Reno" 717endchoice 718 719endif 720 721config TCP_CONG_CUBIC 722 tristate 723 depends on !TCP_CONG_ADVANCED 724 default y 725 726config DEFAULT_TCP_CONG 727 string 728 default "bic" if DEFAULT_BIC 729 default "cubic" if DEFAULT_CUBIC 730 default "htcp" if DEFAULT_HTCP 731 default "hybla" if DEFAULT_HYBLA 732 default "vegas" if DEFAULT_VEGAS 733 default "westwood" if DEFAULT_WESTWOOD 734 default "veno" if DEFAULT_VENO 735 default "reno" if DEFAULT_RENO 736 default "dctcp" if DEFAULT_DCTCP 737 default "cdg" if DEFAULT_CDG 738 default "bbr" if DEFAULT_BBR 739 default "cubic" 740 741config TCP_MD5SIG 742 bool "TCP: MD5 Signature Option support (RFC2385)" 743 select CRYPTO 744 select CRYPTO_MD5 745 ---help--- 746 RFC2385 specifies a method of giving MD5 protection to TCP sessions. 747 Its main (only?) use is to protect BGP sessions between core routers 748 on the Internet. 749 750 If unsure, say N. 751