Kconfig 26 KB

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  1. #
  2. # IP configuration
  3. #
  4. config 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. config IP_ADVANCED_ROUTER
  14. bool "IP: advanced router"
  15. ---help---
  16. If you intend to run your Linux box mostly as a router, i.e. as a
  17. computer that forwards and redistributes network packets, say Y; you
  18. will then be presented with several options that allow more precise
  19. control about the routing process.
  20. The answer to this question won't directly affect the kernel:
  21. answering N will just cause the configurator to skip all the
  22. questions about advanced routing.
  23. Note that your box can only act as a router if you enable IP
  24. forwarding in your kernel; you can do that by saying Y to "/proc
  25. file system support" and "Sysctl support" below and executing the
  26. line
  27. echo "1" > /proc/sys/net/ipv4/ip_forward
  28. at boot time after the /proc file system has been mounted.
  29. If you turn on IP forwarding, you should consider the rp_filter, which
  30. automatically rejects incoming packets if the routing table entry
  31. for their source address doesn't match the network interface they're
  32. arriving on. This has security advantages because it prevents the
  33. so-called IP spoofing, however it can pose problems if you use
  34. asymmetric routing (packets from you to a host take a different path
  35. than packets from that host to you) or if you operate a non-routing
  36. host which has several IP addresses on different interfaces. To turn
  37. rp_filter on use:
  38. echo 1 > /proc/sys/net/ipv4/conf/<device>/rp_filter
  39. or
  40. echo 1 > /proc/sys/net/ipv4/conf/all/rp_filter
  41. Note that some distributions enable it in startup scripts.
  42. For details about rp_filter strict and loose mode read
  43. <file:Documentation/networking/ip-sysctl.txt>.
  44. If unsure, say N here.
  45. config IP_FIB_TRIE_STATS
  46. bool "FIB TRIE statistics"
  47. depends on IP_ADVANCED_ROUTER
  48. ---help---
  49. Keep track of statistics on structure of FIB TRIE table.
  50. Useful for testing and measuring TRIE performance.
  51. config IP_MULTIPLE_TABLES
  52. bool "IP: policy routing"
  53. depends on IP_ADVANCED_ROUTER
  54. select FIB_RULES
  55. ---help---
  56. Normally, a router decides what to do with a received packet based
  57. solely on the packet's final destination address. If you say Y here,
  58. the Linux router will also be able to take the packet's source
  59. address into account. Furthermore, the TOS (Type-Of-Service) field
  60. of the packet can be used for routing decisions as well.
  61. If you need more information, see the Linux Advanced
  62. Routing and Traffic Control documentation at
  63. <http://lartc.org/howto/lartc.rpdb.html>
  64. If unsure, say N.
  65. config IP_ROUTE_MULTIPATH
  66. bool "IP: equal cost multipath"
  67. depends on IP_ADVANCED_ROUTER
  68. help
  69. Normally, the routing tables specify a single action to be taken in
  70. a deterministic manner for a given packet. If you say Y here
  71. however, it becomes possible to attach several actions to a packet
  72. pattern, in effect specifying several alternative paths to travel
  73. for those packets. The router considers all these paths to be of
  74. equal "cost" and chooses one of them in a non-deterministic fashion
  75. if a matching packet arrives.
  76. config IP_ROUTE_VERBOSE
  77. bool "IP: verbose route monitoring"
  78. depends on IP_ADVANCED_ROUTER
  79. help
  80. If you say Y here, which is recommended, then the kernel will print
  81. verbose messages regarding the routing, for example warnings about
  82. received packets which look strange and could be evidence of an
  83. attack or a misconfigured system somewhere. The information is
  84. handled by the klogd daemon which is responsible for kernel messages
  85. ("man klogd").
  86. config IP_ROUTE_CLASSID
  87. bool
  88. config IP_PNP
  89. bool "IP: kernel level autoconfiguration"
  90. help
  91. This enables automatic configuration of IP addresses of devices and
  92. of the routing table during kernel boot, based on either information
  93. supplied on the kernel command line or by BOOTP or RARP protocols.
  94. You need to say Y only for diskless machines requiring network
  95. access to boot (in which case you want to say Y to "Root file system
  96. on NFS" as well), because all other machines configure the network
  97. in their startup scripts.
  98. config IP_PNP_DHCP
  99. bool "IP: DHCP support"
  100. depends on IP_PNP
  101. ---help---
  102. If you want your Linux box to mount its whole root file system (the
  103. one containing the directory /) from some other computer over the
  104. net via NFS and you want the IP address of your computer to be
  105. discovered automatically at boot time using the DHCP protocol (a
  106. special protocol designed for doing this job), say Y here. In case
  107. the boot ROM of your network card was designed for booting Linux and
  108. does DHCP itself, providing all necessary information on the kernel
  109. command line, you can say N here.
  110. If unsure, say Y. Note that if you want to use DHCP, a DHCP server
  111. must be operating on your network. Read
  112. <file:Documentation/filesystems/nfs/nfsroot.txt> for details.
  113. config IP_PNP_BOOTP
  114. bool "IP: BOOTP support"
  115. depends on IP_PNP
  116. ---help---
  117. If you want your Linux box to mount its whole root file system (the
  118. one containing the directory /) from some other computer over the
  119. net via NFS and you want the IP address of your computer to be
  120. discovered automatically at boot time using the BOOTP protocol (a
  121. special protocol designed for doing this job), say Y here. In case
  122. the boot ROM of your network card was designed for booting Linux and
  123. does BOOTP itself, providing all necessary information on the kernel
  124. command line, you can say N here. If unsure, say Y. Note that if you
  125. want to use BOOTP, a BOOTP server must be operating on your network.
  126. Read <file:Documentation/filesystems/nfs/nfsroot.txt> for details.
  127. config IP_PNP_RARP
  128. bool "IP: RARP support"
  129. depends on IP_PNP
  130. help
  131. If you want your Linux box to mount its whole root file system (the
  132. one containing the directory /) from some other computer over the
  133. net via NFS and you want the IP address of your computer to be
  134. discovered automatically at boot time using the RARP protocol (an
  135. older protocol which is being obsoleted by BOOTP and DHCP), say Y
  136. here. Note that if you want to use RARP, a RARP server must be
  137. operating on your network. Read
  138. <file:Documentation/filesystems/nfs/nfsroot.txt> for details.
  139. config NET_IPIP
  140. tristate "IP: tunneling"
  141. select INET_TUNNEL
  142. select NET_IP_TUNNEL
  143. ---help---
  144. Tunneling means encapsulating data of one protocol type within
  145. another protocol and sending it over a channel that understands the
  146. encapsulating protocol. This particular tunneling driver implements
  147. encapsulation of IP within IP, which sounds kind of pointless, but
  148. can be useful if you want to make your (or some other) machine
  149. appear on a different network than it physically is, or to use
  150. mobile-IP facilities (allowing laptops to seamlessly move between
  151. networks without changing their IP addresses).
  152. Saying Y to this option will produce two modules ( = code which can
  153. be inserted in and removed from the running kernel whenever you
  154. want). Most people won't need this and can say N.
  155. config NET_IPGRE_DEMUX
  156. tristate "IP: GRE demultiplexer"
  157. help
  158. This is helper module to demultiplex GRE packets on GRE version field criteria.
  159. Required by ip_gre and pptp modules.
  160. config NET_IP_TUNNEL
  161. tristate
  162. select DST_CACHE
  163. select GRO_CELLS
  164. default n
  165. config NET_IPGRE
  166. tristate "IP: GRE tunnels over IP"
  167. depends on (IPV6 || IPV6=n) && NET_IPGRE_DEMUX
  168. select NET_IP_TUNNEL
  169. help
  170. Tunneling means encapsulating data of one protocol type within
  171. another protocol and sending it over a channel that understands the
  172. encapsulating protocol. This particular tunneling driver implements
  173. GRE (Generic Routing Encapsulation) and at this time allows
  174. encapsulating of IPv4 or IPv6 over existing IPv4 infrastructure.
  175. This driver is useful if the other endpoint is a Cisco router: Cisco
  176. likes GRE much better than the other Linux tunneling driver ("IP
  177. tunneling" above). In addition, GRE allows multicast redistribution
  178. through the tunnel.
  179. config NET_IPGRE_BROADCAST
  180. bool "IP: broadcast GRE over IP"
  181. depends on IP_MULTICAST && NET_IPGRE
  182. help
  183. One application of GRE/IP is to construct a broadcast WAN (Wide Area
  184. Network), which looks like a normal Ethernet LAN (Local Area
  185. Network), but can be distributed all over the Internet. If you want
  186. to do that, say Y here and to "IP multicast routing" below.
  187. config IP_MROUTE_COMMON
  188. bool
  189. depends on IP_MROUTE || IPV6_MROUTE
  190. config IP_MROUTE
  191. bool "IP: multicast routing"
  192. depends on IP_MULTICAST
  193. select IP_MROUTE_COMMON
  194. help
  195. This is used if you want your machine to act as a router for IP
  196. packets that have several destination addresses. It is needed on the
  197. MBONE, a high bandwidth network on top of the Internet which carries
  198. audio and video broadcasts. In order to do that, you would most
  199. likely run the program mrouted. If you haven't heard about it, you
  200. don't need it.
  201. config IP_MROUTE_MULTIPLE_TABLES
  202. bool "IP: multicast policy routing"
  203. depends on IP_MROUTE && IP_ADVANCED_ROUTER
  204. select FIB_RULES
  205. help
  206. Normally, a multicast router runs a userspace daemon and decides
  207. what to do with a multicast packet based on the source and
  208. destination addresses. If you say Y here, the multicast router
  209. will also be able to take interfaces and packet marks into
  210. account and run multiple instances of userspace daemons
  211. simultaneously, each one handling a single table.
  212. If unsure, say N.
  213. config IP_PIMSM_V1
  214. bool "IP: PIM-SM version 1 support"
  215. depends on IP_MROUTE
  216. help
  217. Kernel side support for Sparse Mode PIM (Protocol Independent
  218. Multicast) version 1. This multicast routing protocol is used widely
  219. because Cisco supports it. You need special software to use it
  220. (pimd-v1). Please see <http://netweb.usc.edu/pim/> for more
  221. information about PIM.
  222. Say Y if you want to use PIM-SM v1. Note that you can say N here if
  223. you just want to use Dense Mode PIM.
  224. config IP_PIMSM_V2
  225. bool "IP: PIM-SM version 2 support"
  226. depends on IP_MROUTE
  227. help
  228. Kernel side support for Sparse Mode PIM version 2. In order to use
  229. this, you need an experimental routing daemon supporting it (pimd or
  230. gated-5). This routing protocol is not used widely, so say N unless
  231. you want to play with it.
  232. config SYN_COOKIES
  233. bool "IP: TCP syncookie support"
  234. ---help---
  235. Normal TCP/IP networking is open to an attack known as "SYN
  236. flooding". This denial-of-service attack prevents legitimate remote
  237. users from being able to connect to your computer during an ongoing
  238. attack and requires very little work from the attacker, who can
  239. operate from anywhere on the Internet.
  240. SYN cookies provide protection against this type of attack. If you
  241. say Y here, the TCP/IP stack will use a cryptographic challenge
  242. protocol known as "SYN cookies" to enable legitimate users to
  243. continue to connect, even when your machine is under attack. There
  244. is no need for the legitimate users to change their TCP/IP software;
  245. SYN cookies work transparently to them. For technical information
  246. about SYN cookies, check out <http://cr.yp.to/syncookies.html>.
  247. If you are SYN flooded, the source address reported by the kernel is
  248. likely to have been forged by the attacker; it is only reported as
  249. an aid in tracing the packets to their actual source and should not
  250. be taken as absolute truth.
  251. SYN cookies may prevent correct error reporting on clients when the
  252. server is really overloaded. If this happens frequently better turn
  253. them off.
  254. If you say Y here, you can disable SYN cookies at run time by
  255. saying Y to "/proc file system support" and
  256. "Sysctl support" below and executing the command
  257. echo 0 > /proc/sys/net/ipv4/tcp_syncookies
  258. after the /proc file system has been mounted.
  259. If unsure, say N.
  260. config NET_IPVTI
  261. tristate "Virtual (secure) IP: tunneling"
  262. select INET_TUNNEL
  263. select NET_IP_TUNNEL
  264. depends on INET_XFRM_MODE_TUNNEL
  265. ---help---
  266. Tunneling means encapsulating data of one protocol type within
  267. another protocol and sending it over a channel that understands the
  268. encapsulating protocol. This can be used with xfrm mode tunnel to give
  269. the notion of a secure tunnel for IPSEC and then use routing protocol
  270. on top.
  271. config NET_UDP_TUNNEL
  272. tristate
  273. select NET_IP_TUNNEL
  274. default n
  275. config NET_FOU
  276. tristate "IP: Foo (IP protocols) over UDP"
  277. select XFRM
  278. select NET_UDP_TUNNEL
  279. ---help---
  280. Foo over UDP allows any IP protocol to be directly encapsulated
  281. over UDP include tunnels (IPIP, GRE, SIT). By encapsulating in UDP
  282. network mechanisms and optimizations for UDP (such as ECMP
  283. and RSS) can be leveraged to provide better service.
  284. config NET_FOU_IP_TUNNELS
  285. bool "IP: FOU encapsulation of IP tunnels"
  286. depends on NET_IPIP || NET_IPGRE || IPV6_SIT
  287. select NET_FOU
  288. ---help---
  289. Allow configuration of FOU or GUE encapsulation for IP tunnels.
  290. When this option is enabled IP tunnels can be configured to use
  291. FOU or GUE encapsulation.
  292. config INET_AH
  293. tristate "IP: AH transformation"
  294. select XFRM_ALGO
  295. select CRYPTO
  296. select CRYPTO_HMAC
  297. select CRYPTO_MD5
  298. select CRYPTO_SHA1
  299. ---help---
  300. Support for IPsec AH.
  301. If unsure, say Y.
  302. config INET_ESP
  303. tristate "IP: ESP transformation"
  304. select XFRM_ALGO
  305. select CRYPTO
  306. select CRYPTO_AUTHENC
  307. select CRYPTO_HMAC
  308. select CRYPTO_MD5
  309. select CRYPTO_CBC
  310. select CRYPTO_SHA1
  311. select CRYPTO_DES
  312. select CRYPTO_ECHAINIV
  313. ---help---
  314. Support for IPsec ESP.
  315. If unsure, say Y.
  316. config INET_ESP_OFFLOAD
  317. tristate "IP: ESP transformation offload"
  318. depends on INET_ESP
  319. select XFRM_OFFLOAD
  320. default n
  321. ---help---
  322. Support for ESP transformation offload. This makes sense
  323. only if this system really does IPsec and want to do it
  324. with high throughput. A typical desktop system does not
  325. need it, even if it does IPsec.
  326. If unsure, say N.
  327. config INET_IPCOMP
  328. tristate "IP: IPComp transformation"
  329. select INET_XFRM_TUNNEL
  330. select XFRM_IPCOMP
  331. ---help---
  332. Support for IP Payload Compression Protocol (IPComp) (RFC3173),
  333. typically needed for IPsec.
  334. If unsure, say Y.
  335. config INET_XFRM_TUNNEL
  336. tristate
  337. select INET_TUNNEL
  338. default n
  339. config INET_TUNNEL
  340. tristate
  341. default n
  342. config INET_XFRM_MODE_TRANSPORT
  343. tristate "IP: IPsec transport mode"
  344. default y
  345. select XFRM
  346. ---help---
  347. Support for IPsec transport mode.
  348. If unsure, say Y.
  349. config INET_XFRM_MODE_TUNNEL
  350. tristate "IP: IPsec tunnel mode"
  351. default y
  352. select XFRM
  353. ---help---
  354. Support for IPsec tunnel mode.
  355. If unsure, say Y.
  356. config INET_XFRM_MODE_BEET
  357. tristate "IP: IPsec BEET mode"
  358. default y
  359. select XFRM
  360. ---help---
  361. Support for IPsec BEET mode.
  362. If unsure, say Y.
  363. config INET_DIAG
  364. tristate "INET: socket monitoring interface"
  365. default y
  366. ---help---
  367. Support for INET (TCP, DCCP, etc) socket monitoring interface used by
  368. native Linux tools such as ss. ss is included in iproute2, currently
  369. downloadable at:
  370. http://www.linuxfoundation.org/collaborate/workgroups/networking/iproute2
  371. If unsure, say Y.
  372. config INET_TCP_DIAG
  373. depends on INET_DIAG
  374. def_tristate INET_DIAG
  375. config INET_UDP_DIAG
  376. tristate "UDP: socket monitoring interface"
  377. depends on INET_DIAG && (IPV6 || IPV6=n)
  378. default n
  379. ---help---
  380. Support for UDP socket monitoring interface used by the ss tool.
  381. If unsure, say Y.
  382. config INET_RAW_DIAG
  383. tristate "RAW: socket monitoring interface"
  384. depends on INET_DIAG && (IPV6 || IPV6=n)
  385. default n
  386. ---help---
  387. Support for RAW socket monitoring interface used by the ss tool.
  388. If unsure, say Y.
  389. config INET_DIAG_DESTROY
  390. bool "INET: allow privileged process to administratively close sockets"
  391. depends on INET_DIAG
  392. default n
  393. ---help---
  394. Provides a SOCK_DESTROY operation that allows privileged processes
  395. (e.g., a connection manager or a network administration tool such as
  396. ss) to close sockets opened by other processes. Closing a socket in
  397. this way interrupts any blocking read/write/connect operations on
  398. the socket and causes future socket calls to behave as if the socket
  399. had been disconnected.
  400. If unsure, say N.
  401. menuconfig TCP_CONG_ADVANCED
  402. bool "TCP: advanced congestion control"
  403. ---help---
  404. Support for selection of various TCP congestion control
  405. modules.
  406. Nearly all users can safely say no here, and a safe default
  407. selection will be made (CUBIC with new Reno as a fallback).
  408. If unsure, say N.
  409. if TCP_CONG_ADVANCED
  410. config TCP_CONG_BIC
  411. tristate "Binary Increase Congestion (BIC) control"
  412. default m
  413. ---help---
  414. BIC-TCP is a sender-side only change that ensures a linear RTT
  415. fairness under large windows while offering both scalability and
  416. bounded TCP-friendliness. The protocol combines two schemes
  417. called additive increase and binary search increase. When the
  418. congestion window is large, additive increase with a large
  419. increment ensures linear RTT fairness as well as good
  420. scalability. Under small congestion windows, binary search
  421. increase provides TCP friendliness.
  422. See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/
  423. config TCP_CONG_CUBIC
  424. tristate "CUBIC TCP"
  425. default y
  426. ---help---
  427. This is version 2.0 of BIC-TCP which uses a cubic growth function
  428. among other techniques.
  429. See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/cubic-paper.pdf
  430. config TCP_CONG_WESTWOOD
  431. tristate "TCP Westwood+"
  432. default m
  433. ---help---
  434. TCP Westwood+ is a sender-side only modification of the TCP Reno
  435. protocol stack that optimizes the performance of TCP congestion
  436. control. It is based on end-to-end bandwidth estimation to set
  437. congestion window and slow start threshold after a congestion
  438. episode. Using this estimation, TCP Westwood+ adaptively sets a
  439. slow start threshold and a congestion window which takes into
  440. account the bandwidth used at the time congestion is experienced.
  441. TCP Westwood+ significantly increases fairness wrt TCP Reno in
  442. wired networks and throughput over wireless links.
  443. config TCP_CONG_HTCP
  444. tristate "H-TCP"
  445. default m
  446. ---help---
  447. H-TCP is a send-side only modifications of the TCP Reno
  448. protocol stack that optimizes the performance of TCP
  449. congestion control for high speed network links. It uses a
  450. modeswitch to change the alpha and beta parameters of TCP Reno
  451. based on network conditions and in a way so as to be fair with
  452. other Reno and H-TCP flows.
  453. config TCP_CONG_HSTCP
  454. tristate "High Speed TCP"
  455. default n
  456. ---help---
  457. Sally Floyd's High Speed TCP (RFC 3649) congestion control.
  458. A modification to TCP's congestion control mechanism for use
  459. with large congestion windows. A table indicates how much to
  460. increase the congestion window by when an ACK is received.
  461. For more detail see http://www.icir.org/floyd/hstcp.html
  462. config TCP_CONG_HYBLA
  463. tristate "TCP-Hybla congestion control algorithm"
  464. default n
  465. ---help---
  466. TCP-Hybla is a sender-side only change that eliminates penalization of
  467. long-RTT, large-bandwidth connections, like when satellite legs are
  468. involved, especially when sharing a common bottleneck with normal
  469. terrestrial connections.
  470. config TCP_CONG_VEGAS
  471. tristate "TCP Vegas"
  472. default n
  473. ---help---
  474. TCP Vegas is a sender-side only change to TCP that anticipates
  475. the onset of congestion by estimating the bandwidth. TCP Vegas
  476. adjusts the sending rate by modifying the congestion
  477. window. TCP Vegas should provide less packet loss, but it is
  478. not as aggressive as TCP Reno.
  479. config TCP_CONG_NV
  480. tristate "TCP NV"
  481. default n
  482. ---help---
  483. TCP NV is a follow up to TCP Vegas. It has been modified to deal with
  484. 10G networks, measurement noise introduced by LRO, GRO and interrupt
  485. coalescence. In addition, it will decrease its cwnd multiplicatively
  486. instead of linearly.
  487. Note that in general congestion avoidance (cwnd decreased when # packets
  488. queued grows) cannot coexist with congestion control (cwnd decreased only
  489. when there is packet loss) due to fairness issues. One scenario when they
  490. can coexist safely is when the CA flows have RTTs << CC flows RTTs.
  491. For further details see http://www.brakmo.org/networking/tcp-nv/
  492. config TCP_CONG_SCALABLE
  493. tristate "Scalable TCP"
  494. default n
  495. ---help---
  496. Scalable TCP is a sender-side only change to TCP which uses a
  497. MIMD congestion control algorithm which has some nice scaling
  498. properties, though is known to have fairness issues.
  499. See http://www.deneholme.net/tom/scalable/
  500. config TCP_CONG_LP
  501. tristate "TCP Low Priority"
  502. default n
  503. ---help---
  504. TCP Low Priority (TCP-LP), a distributed algorithm whose goal is
  505. to utilize only the excess network bandwidth as compared to the
  506. ``fair share`` of bandwidth as targeted by TCP.
  507. See http://www-ece.rice.edu/networks/TCP-LP/
  508. config TCP_CONG_VENO
  509. tristate "TCP Veno"
  510. default n
  511. ---help---
  512. TCP Veno is a sender-side only enhancement of TCP to obtain better
  513. throughput over wireless networks. TCP Veno makes use of state
  514. distinguishing to circumvent the difficult judgment of the packet loss
  515. type. TCP Veno cuts down less congestion window in response to random
  516. loss packets.
  517. See <http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=1177186>
  518. config TCP_CONG_YEAH
  519. tristate "YeAH TCP"
  520. select TCP_CONG_VEGAS
  521. default n
  522. ---help---
  523. YeAH-TCP is a sender-side high-speed enabled TCP congestion control
  524. algorithm, which uses a mixed loss/delay approach to compute the
  525. congestion window. It's design goals target high efficiency,
  526. internal, RTT and Reno fairness, resilience to link loss while
  527. keeping network elements load as low as possible.
  528. For further details look here:
  529. http://wil.cs.caltech.edu/pfldnet2007/paper/YeAH_TCP.pdf
  530. config TCP_CONG_ILLINOIS
  531. tristate "TCP Illinois"
  532. default n
  533. ---help---
  534. TCP-Illinois is a sender-side modification of TCP Reno for
  535. high speed long delay links. It uses round-trip-time to
  536. adjust the alpha and beta parameters to achieve a higher average
  537. throughput and maintain fairness.
  538. For further details see:
  539. http://www.ews.uiuc.edu/~shaoliu/tcpillinois/index.html
  540. config TCP_CONG_DCTCP
  541. tristate "DataCenter TCP (DCTCP)"
  542. default n
  543. ---help---
  544. DCTCP leverages Explicit Congestion Notification (ECN) in the network to
  545. provide multi-bit feedback to the end hosts. It is designed to provide:
  546. - High burst tolerance (incast due to partition/aggregate),
  547. - Low latency (short flows, queries),
  548. - High throughput (continuous data updates, large file transfers) with
  549. commodity, shallow-buffered switches.
  550. All switches in the data center network running DCTCP must support
  551. ECN marking and be configured for marking when reaching defined switch
  552. buffer thresholds. The default ECN marking threshold heuristic for
  553. DCTCP on switches is 20 packets (30KB) at 1Gbps, and 65 packets
  554. (~100KB) at 10Gbps, but might need further careful tweaking.
  555. For further details see:
  556. http://simula.stanford.edu/~alizade/Site/DCTCP_files/dctcp-final.pdf
  557. config TCP_CONG_CDG
  558. tristate "CAIA Delay-Gradient (CDG)"
  559. default n
  560. ---help---
  561. CAIA Delay-Gradient (CDG) is a TCP congestion control that modifies
  562. the TCP sender in order to:
  563. o Use the delay gradient as a congestion signal.
  564. o Back off with an average probability that is independent of the RTT.
  565. o Coexist with flows that use loss-based congestion control.
  566. o Tolerate packet loss unrelated to congestion.
  567. For further details see:
  568. D.A. Hayes and G. Armitage. "Revisiting TCP congestion control using
  569. delay gradients." In Networking 2011. Preprint: http://goo.gl/No3vdg
  570. config TCP_CONG_BBR
  571. tristate "BBR TCP"
  572. default n
  573. ---help---
  574. BBR (Bottleneck Bandwidth and RTT) TCP congestion control aims to
  575. maximize network utilization and minimize queues. It builds an explicit
  576. model of the the bottleneck delivery rate and path round-trip
  577. propagation delay. It tolerates packet loss and delay unrelated to
  578. congestion. It can operate over LAN, WAN, cellular, wifi, or cable
  579. modem links. It can coexist with flows that use loss-based congestion
  580. control, and can operate with shallow buffers, deep buffers,
  581. bufferbloat, policers, or AQM schemes that do not provide a delay
  582. signal. It requires the fq ("Fair Queue") pacing packet scheduler.
  583. choice
  584. prompt "Default TCP congestion control"
  585. default DEFAULT_CUBIC
  586. help
  587. Select the TCP congestion control that will be used by default
  588. for all connections.
  589. config DEFAULT_BIC
  590. bool "Bic" if TCP_CONG_BIC=y
  591. config DEFAULT_CUBIC
  592. bool "Cubic" if TCP_CONG_CUBIC=y
  593. config DEFAULT_HTCP
  594. bool "Htcp" if TCP_CONG_HTCP=y
  595. config DEFAULT_HYBLA
  596. bool "Hybla" if TCP_CONG_HYBLA=y
  597. config DEFAULT_VEGAS
  598. bool "Vegas" if TCP_CONG_VEGAS=y
  599. config DEFAULT_VENO
  600. bool "Veno" if TCP_CONG_VENO=y
  601. config DEFAULT_WESTWOOD
  602. bool "Westwood" if TCP_CONG_WESTWOOD=y
  603. config DEFAULT_DCTCP
  604. bool "DCTCP" if TCP_CONG_DCTCP=y
  605. config DEFAULT_CDG
  606. bool "CDG" if TCP_CONG_CDG=y
  607. config DEFAULT_BBR
  608. bool "BBR" if TCP_CONG_BBR=y
  609. config DEFAULT_RENO
  610. bool "Reno"
  611. endchoice
  612. endif
  613. config TCP_CONG_CUBIC
  614. tristate
  615. depends on !TCP_CONG_ADVANCED
  616. default y
  617. config DEFAULT_TCP_CONG
  618. string
  619. default "bic" if DEFAULT_BIC
  620. default "cubic" if DEFAULT_CUBIC
  621. default "htcp" if DEFAULT_HTCP
  622. default "hybla" if DEFAULT_HYBLA
  623. default "vegas" if DEFAULT_VEGAS
  624. default "westwood" if DEFAULT_WESTWOOD
  625. default "veno" if DEFAULT_VENO
  626. default "reno" if DEFAULT_RENO
  627. default "dctcp" if DEFAULT_DCTCP
  628. default "cdg" if DEFAULT_CDG
  629. default "bbr" if DEFAULT_BBR
  630. default "cubic"
  631. config TCP_MD5SIG
  632. bool "TCP: MD5 Signature Option support (RFC2385)"
  633. select CRYPTO
  634. select CRYPTO_MD5
  635. ---help---
  636. RFC2385 specifies a method of giving MD5 protection to TCP sessions.
  637. Its main (only?) use is to protect BGP sessions between core routers
  638. on the Internet.
  639. If unsure, say N.