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 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 GENEVE 335 tristate "Generic Network Virtualization Encapsulation (Geneve)" 336 depends on INET 337 select NET_UDP_TUNNEL 338 ---help--- 339 This allows one to create Geneve virtual interfaces that provide 340 Layer 2 Networks over Layer 3 Networks. Geneve is often used 341 to tunnel virtual network infrastructure in virtualized environments. 342 For more information see: 343 http://tools.ietf.org/html/draft-gross-geneve-01 344 345 To compile this driver as a module, choose M here: the module 346 347 348config INET_AH 349 tristate "IP: AH transformation" 350 select XFRM_ALGO 351 select CRYPTO 352 select CRYPTO_HMAC 353 select CRYPTO_MD5 354 select CRYPTO_SHA1 355 ---help--- 356 Support for IPsec AH. 357 358 If unsure, say Y. 359 360config INET_ESP 361 tristate "IP: ESP transformation" 362 select XFRM_ALGO 363 select CRYPTO 364 select CRYPTO_AUTHENC 365 select CRYPTO_HMAC 366 select CRYPTO_MD5 367 select CRYPTO_CBC 368 select CRYPTO_SHA1 369 select CRYPTO_DES 370 ---help--- 371 Support for IPsec ESP. 372 373 If unsure, say Y. 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_LRO 422 tristate "Large Receive Offload (ipv4/tcp)" 423 default y 424 ---help--- 425 Support for Large Receive Offload (ipv4/tcp). 426 427 If unsure, say Y. 428 429config INET_DIAG 430 tristate "INET: socket monitoring interface" 431 default y 432 ---help--- 433 Support for INET (TCP, DCCP, etc) socket monitoring interface used by 434 native Linux tools such as ss. ss is included in iproute2, currently 435 downloadable at: 436 437 http://www.linuxfoundation.org/collaborate/workgroups/networking/iproute2 438 439 If unsure, say Y. 440 441config INET_TCP_DIAG 442 depends on INET_DIAG 443 def_tristate INET_DIAG 444 445config INET_UDP_DIAG 446 tristate "UDP: socket monitoring interface" 447 depends on INET_DIAG && (IPV6 || IPV6=n) 448 default n 449 ---help--- 450 Support for UDP socket monitoring interface used by the ss tool. 451 If unsure, say Y. 452 453menuconfig TCP_CONG_ADVANCED 454 bool "TCP: advanced congestion control" 455 ---help--- 456 Support for selection of various TCP congestion control 457 modules. 458 459 Nearly all users can safely say no here, and a safe default 460 selection will be made (CUBIC with new Reno as a fallback). 461 462 If unsure, say N. 463 464if TCP_CONG_ADVANCED 465 466config TCP_CONG_BIC 467 tristate "Binary Increase Congestion (BIC) control" 468 default m 469 ---help--- 470 BIC-TCP is a sender-side only change that ensures a linear RTT 471 fairness under large windows while offering both scalability and 472 bounded TCP-friendliness. The protocol combines two schemes 473 called additive increase and binary search increase. When the 474 congestion window is large, additive increase with a large 475 increment ensures linear RTT fairness as well as good 476 scalability. Under small congestion windows, binary search 477 increase provides TCP friendliness. 478 See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/ 479 480config TCP_CONG_CUBIC 481 tristate "CUBIC TCP" 482 default y 483 ---help--- 484 This is version 2.0 of BIC-TCP which uses a cubic growth function 485 among other techniques. 486 See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/cubic-paper.pdf 487 488config TCP_CONG_WESTWOOD 489 tristate "TCP Westwood+" 490 default m 491 ---help--- 492 TCP Westwood+ is a sender-side only modification of the TCP Reno 493 protocol stack that optimizes the performance of TCP congestion 494 control. It is based on end-to-end bandwidth estimation to set 495 congestion window and slow start threshold after a congestion 496 episode. Using this estimation, TCP Westwood+ adaptively sets a 497 slow start threshold and a congestion window which takes into 498 account the bandwidth used at the time congestion is experienced. 499 TCP Westwood+ significantly increases fairness wrt TCP Reno in 500 wired networks and throughput over wireless links. 501 502config TCP_CONG_HTCP 503 tristate "H-TCP" 504 default m 505 ---help--- 506 H-TCP is a send-side only modifications of the TCP Reno 507 protocol stack that optimizes the performance of TCP 508 congestion control for high speed network links. It uses a 509 modeswitch to change the alpha and beta parameters of TCP Reno 510 based on network conditions and in a way so as to be fair with 511 other Reno and H-TCP flows. 512 513config TCP_CONG_HSTCP 514 tristate "High Speed TCP" 515 default n 516 ---help--- 517 Sally Floyd's High Speed TCP (RFC 3649) congestion control. 518 A modification to TCP's congestion control mechanism for use 519 with large congestion windows. A table indicates how much to 520 increase the congestion window by when an ACK is received. 521 For more detail see http://www.icir.org/floyd/hstcp.html 522 523config TCP_CONG_HYBLA 524 tristate "TCP-Hybla congestion control algorithm" 525 default n 526 ---help--- 527 TCP-Hybla is a sender-side only change that eliminates penalization of 528 long-RTT, large-bandwidth connections, like when satellite legs are 529 involved, especially when sharing a common bottleneck with normal 530 terrestrial connections. 531 532config TCP_CONG_VEGAS 533 tristate "TCP Vegas" 534 default n 535 ---help--- 536 TCP Vegas is a sender-side only change to TCP that anticipates 537 the onset of congestion by estimating the bandwidth. TCP Vegas 538 adjusts the sending rate by modifying the congestion 539 window. TCP Vegas should provide less packet loss, but it is 540 not as aggressive as TCP Reno. 541 542config TCP_CONG_SCALABLE 543 tristate "Scalable TCP" 544 default n 545 ---help--- 546 Scalable TCP is a sender-side only change to TCP which uses a 547 MIMD congestion control algorithm which has some nice scaling 548 properties, though is known to have fairness issues. 549 See http://www.deneholme.net/tom/scalable/ 550 551config TCP_CONG_LP 552 tristate "TCP Low Priority" 553 default n 554 ---help--- 555 TCP Low Priority (TCP-LP), a distributed algorithm whose goal is 556 to utilize only the excess network bandwidth as compared to the 557 ``fair share`` of bandwidth as targeted by TCP. 558 See http://www-ece.rice.edu/networks/TCP-LP/ 559 560config TCP_CONG_VENO 561 tristate "TCP Veno" 562 default n 563 ---help--- 564 TCP Veno is a sender-side only enhancement of TCP to obtain better 565 throughput over wireless networks. TCP Veno makes use of state 566 distinguishing to circumvent the difficult judgment of the packet loss 567 type. TCP Veno cuts down less congestion window in response to random 568 loss packets. 569 See <http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=1177186> 570 571config TCP_CONG_YEAH 572 tristate "YeAH TCP" 573 select TCP_CONG_VEGAS 574 default n 575 ---help--- 576 YeAH-TCP is a sender-side high-speed enabled TCP congestion control 577 algorithm, which uses a mixed loss/delay approach to compute the 578 congestion window. It's design goals target high efficiency, 579 internal, RTT and Reno fairness, resilience to link loss while 580 keeping network elements load as low as possible. 581 582 For further details look here: 583 http://wil.cs.caltech.edu/pfldnet2007/paper/YeAH_TCP.pdf 584 585config TCP_CONG_ILLINOIS 586 tristate "TCP Illinois" 587 default n 588 ---help--- 589 TCP-Illinois is a sender-side modification of TCP Reno for 590 high speed long delay links. It uses round-trip-time to 591 adjust the alpha and beta parameters to achieve a higher average 592 throughput and maintain fairness. 593 594 For further details see: 595 http://www.ews.uiuc.edu/~shaoliu/tcpillinois/index.html 596 597config TCP_CONG_DCTCP 598 tristate "DataCenter TCP (DCTCP)" 599 default n 600 ---help--- 601 DCTCP leverages Explicit Congestion Notification (ECN) in the network to 602 provide multi-bit feedback to the end hosts. It is designed to provide: 603 604 - High burst tolerance (incast due to partition/aggregate), 605 - Low latency (short flows, queries), 606 - High throughput (continuous data updates, large file transfers) with 607 commodity, shallow-buffered switches. 608 609 All switches in the data center network running DCTCP must support 610 ECN marking and be configured for marking when reaching defined switch 611 buffer thresholds. The default ECN marking threshold heuristic for 612 DCTCP on switches is 20 packets (30KB) at 1Gbps, and 65 packets 613 (~100KB) at 10Gbps, but might need further careful tweaking. 614 615 For further details see: 616 http://simula.stanford.edu/~alizade/Site/DCTCP_files/dctcp-final.pdf 617 618choice 619 prompt "Default TCP congestion control" 620 default DEFAULT_CUBIC 621 help 622 Select the TCP congestion control that will be used by default 623 for all connections. 624 625 config DEFAULT_BIC 626 bool "Bic" if TCP_CONG_BIC=y 627 628 config DEFAULT_CUBIC 629 bool "Cubic" if TCP_CONG_CUBIC=y 630 631 config DEFAULT_HTCP 632 bool "Htcp" if TCP_CONG_HTCP=y 633 634 config DEFAULT_HYBLA 635 bool "Hybla" if TCP_CONG_HYBLA=y 636 637 config DEFAULT_VEGAS 638 bool "Vegas" if TCP_CONG_VEGAS=y 639 640 config DEFAULT_VENO 641 bool "Veno" if TCP_CONG_VENO=y 642 643 config DEFAULT_WESTWOOD 644 bool "Westwood" if TCP_CONG_WESTWOOD=y 645 646 config DEFAULT_DCTCP 647 bool "DCTCP" if TCP_CONG_DCTCP=y 648 649 config DEFAULT_RENO 650 bool "Reno" 651endchoice 652 653endif 654 655config TCP_CONG_CUBIC 656 tristate 657 depends on !TCP_CONG_ADVANCED 658 default y 659 660config DEFAULT_TCP_CONG 661 string 662 default "bic" if DEFAULT_BIC 663 default "cubic" if DEFAULT_CUBIC 664 default "htcp" if DEFAULT_HTCP 665 default "hybla" if DEFAULT_HYBLA 666 default "vegas" if DEFAULT_VEGAS 667 default "westwood" if DEFAULT_WESTWOOD 668 default "veno" if DEFAULT_VENO 669 default "reno" if DEFAULT_RENO 670 default "dctcp" if DEFAULT_DCTCP 671 default "cubic" 672 673config TCP_MD5SIG 674 bool "TCP: MD5 Signature Option support (RFC2385)" 675 select CRYPTO 676 select CRYPTO_MD5 677 ---help--- 678 RFC2385 specifies a method of giving MD5 protection to TCP sessions. 679 Its main (only?) use is to protect BGP sessions between core routers 680 on the Internet. 681 682 If unsure, say N. 683