11da177e4SLinus Torvalds# 21da177e4SLinus Torvalds# IP configuration 31da177e4SLinus Torvalds# 41da177e4SLinus Torvaldsconfig IP_MULTICAST 51da177e4SLinus Torvalds bool "IP: multicasting" 61da177e4SLinus Torvalds help 71da177e4SLinus Torvalds This is code for addressing several networked computers at once, 81da177e4SLinus Torvalds enlarging your kernel by about 2 KB. You need multicasting if you 91da177e4SLinus Torvalds intend to participate in the MBONE, a high bandwidth network on top 101da177e4SLinus Torvalds of the Internet which carries audio and video broadcasts. More 111da177e4SLinus Torvalds information about the MBONE is on the WWW at 12936bb14cSAdrian Bunk <http://www.savetz.com/mbone/>. Information about the multicast 131da177e4SLinus Torvalds capabilities of the various network cards is contained in 141da177e4SLinus Torvalds <file:Documentation/networking/multicast.txt>. For most people, it's 151da177e4SLinus Torvalds safe to say N. 161da177e4SLinus Torvalds 171da177e4SLinus Torvaldsconfig IP_ADVANCED_ROUTER 181da177e4SLinus Torvalds bool "IP: advanced router" 191da177e4SLinus Torvalds ---help--- 201da177e4SLinus Torvalds If you intend to run your Linux box mostly as a router, i.e. as a 211da177e4SLinus Torvalds computer that forwards and redistributes network packets, say Y; you 221da177e4SLinus Torvalds will then be presented with several options that allow more precise 231da177e4SLinus Torvalds control about the routing process. 241da177e4SLinus Torvalds 251da177e4SLinus Torvalds The answer to this question won't directly affect the kernel: 261da177e4SLinus Torvalds answering N will just cause the configurator to skip all the 271da177e4SLinus Torvalds questions about advanced routing. 281da177e4SLinus Torvalds 291da177e4SLinus Torvalds Note that your box can only act as a router if you enable IP 301da177e4SLinus Torvalds forwarding in your kernel; you can do that by saying Y to "/proc 311da177e4SLinus Torvalds file system support" and "Sysctl support" below and executing the 321da177e4SLinus Torvalds line 331da177e4SLinus Torvalds 341da177e4SLinus Torvalds echo "1" > /proc/sys/net/ipv4/ip_forward 351da177e4SLinus Torvalds 361da177e4SLinus Torvalds at boot time after the /proc file system has been mounted. 371da177e4SLinus Torvalds 38b2cc46a8SJesper Dangaard Brouer If you turn on IP forwarding, you should consider the rp_filter, which 391da177e4SLinus Torvalds automatically rejects incoming packets if the routing table entry 401da177e4SLinus Torvalds for their source address doesn't match the network interface they're 411da177e4SLinus Torvalds arriving on. This has security advantages because it prevents the 421da177e4SLinus Torvalds so-called IP spoofing, however it can pose problems if you use 431da177e4SLinus Torvalds asymmetric routing (packets from you to a host take a different path 441da177e4SLinus Torvalds than packets from that host to you) or if you operate a non-routing 451da177e4SLinus Torvalds host which has several IP addresses on different interfaces. To turn 46d7394372SDave Jones rp_filter on use: 471da177e4SLinus Torvalds 48d7394372SDave Jones echo 1 > /proc/sys/net/ipv4/conf/<device>/rp_filter 49750e9fadSNicolas Dichtel or 50d7394372SDave Jones echo 1 > /proc/sys/net/ipv4/conf/all/rp_filter 511da177e4SLinus Torvalds 52b2cc46a8SJesper Dangaard Brouer Note that some distributions enable it in startup scripts. 53d18921a0SJesper Dangaard Brouer For details about rp_filter strict and loose mode read 54d18921a0SJesper Dangaard Brouer <file:Documentation/networking/ip-sysctl.txt>. 55b2cc46a8SJesper Dangaard Brouer 561da177e4SLinus Torvalds If unsure, say N here. 571da177e4SLinus Torvalds 58bb298ca3SDavid S. Millerchoice 59bb298ca3SDavid S. Miller prompt "Choose IP: FIB lookup algorithm (choose FIB_HASH if unsure)" 60bb298ca3SDavid S. Miller depends on IP_ADVANCED_ROUTER 616876f95fSAdrian Bunk default ASK_IP_FIB_HASH 62bb298ca3SDavid S. Miller 636876f95fSAdrian Bunkconfig ASK_IP_FIB_HASH 64bb298ca3SDavid S. Miller bool "FIB_HASH" 65bb298ca3SDavid S. Miller ---help--- 66bb298ca3SDavid S. Miller Current FIB is very proven and good enough for most users. 67bb298ca3SDavid S. Miller 68bb298ca3SDavid S. Millerconfig IP_FIB_TRIE 69bb298ca3SDavid S. Miller bool "FIB_TRIE" 70bb298ca3SDavid S. Miller ---help--- 7144c09201SMatt LaPlante Use new experimental LC-trie as FIB lookup algorithm. 72bb298ca3SDavid S. Miller This improves lookup performance if you have a large 73bb298ca3SDavid S. Miller number of routes. 74bb298ca3SDavid S. Miller 75bb298ca3SDavid S. Miller LC-trie is a longest matching prefix lookup algorithm which 76bb298ca3SDavid S. Miller performs better than FIB_HASH for large routing tables. 77bb298ca3SDavid S. Miller But, it consumes more memory and is more complex. 78bb298ca3SDavid S. Miller 79bb298ca3SDavid S. Miller LC-trie is described in: 80bb298ca3SDavid S. Miller 81bb298ca3SDavid S. Miller IP-address lookup using LC-tries. Stefan Nilsson and Gunnar Karlsson 82a6e8f27fSJesper Dangaard Brouer IEEE Journal on Selected Areas in Communications, 17(6):1083-1092, 83a6e8f27fSJesper Dangaard Brouer June 1999 84a6e8f27fSJesper Dangaard Brouer 85bb298ca3SDavid S. Miller An experimental study of compression methods for dynamic tries 86bb298ca3SDavid S. Miller Stefan Nilsson and Matti Tikkanen. Algorithmica, 33(1):19-33, 2002. 87631dd1a8SJustin P. Mattock <http://www.csc.kth.se/~snilsson/software/dyntrie2/> 88bb298ca3SDavid S. Miller 89bb298ca3SDavid S. Millerendchoice 90bb298ca3SDavid S. Miller 91bb298ca3SDavid S. Millerconfig IP_FIB_HASH 926876f95fSAdrian Bunk def_bool ASK_IP_FIB_HASH || !IP_ADVANCED_ROUTER 93bb298ca3SDavid S. Miller 9466a2f7fdSStephen Hemmingerconfig IP_FIB_TRIE_STATS 9566a2f7fdSStephen Hemminger bool "FIB TRIE statistics" 9666a2f7fdSStephen Hemminger depends on IP_FIB_TRIE 9766a2f7fdSStephen Hemminger ---help--- 9866a2f7fdSStephen Hemminger Keep track of statistics on structure of FIB TRIE table. 9966a2f7fdSStephen Hemminger Useful for testing and measuring TRIE performance. 10066a2f7fdSStephen Hemminger 1011da177e4SLinus Torvaldsconfig IP_MULTIPLE_TABLES 1021da177e4SLinus Torvalds bool "IP: policy routing" 1031da177e4SLinus Torvalds depends on IP_ADVANCED_ROUTER 104e1ef4bf2SThomas Graf select FIB_RULES 1051da177e4SLinus Torvalds ---help--- 1061da177e4SLinus Torvalds Normally, a router decides what to do with a received packet based 1071da177e4SLinus Torvalds solely on the packet's final destination address. If you say Y here, 1081da177e4SLinus Torvalds the Linux router will also be able to take the packet's source 1091da177e4SLinus Torvalds address into account. Furthermore, the TOS (Type-Of-Service) field 1101da177e4SLinus Torvalds of the packet can be used for routing decisions as well. 1111da177e4SLinus Torvalds 1121da177e4SLinus Torvalds If you are interested in this, please see the preliminary 1131da177e4SLinus Torvalds documentation at <http://www.compendium.com.ar/policy-routing.txt> 1141da177e4SLinus Torvalds and <ftp://post.tepkom.ru/pub/vol2/Linux/docs/advanced-routing.tex>. 1151da177e4SLinus Torvalds You will need supporting software from 1161da177e4SLinus Torvalds <ftp://ftp.tux.org/pub/net/ip-routing/>. 1171da177e4SLinus Torvalds 1181da177e4SLinus Torvalds If unsure, say N. 1191da177e4SLinus Torvalds 1201da177e4SLinus Torvaldsconfig IP_ROUTE_MULTIPATH 1211da177e4SLinus Torvalds bool "IP: equal cost multipath" 1221da177e4SLinus Torvalds depends on IP_ADVANCED_ROUTER 1231da177e4SLinus Torvalds help 1241da177e4SLinus Torvalds Normally, the routing tables specify a single action to be taken in 1251da177e4SLinus Torvalds a deterministic manner for a given packet. If you say Y here 1261da177e4SLinus Torvalds however, it becomes possible to attach several actions to a packet 1271da177e4SLinus Torvalds pattern, in effect specifying several alternative paths to travel 1281da177e4SLinus Torvalds for those packets. The router considers all these paths to be of 1291da177e4SLinus Torvalds equal "cost" and chooses one of them in a non-deterministic fashion 1301da177e4SLinus Torvalds if a matching packet arrives. 1311da177e4SLinus Torvalds 1321da177e4SLinus Torvaldsconfig IP_ROUTE_VERBOSE 1331da177e4SLinus Torvalds bool "IP: verbose route monitoring" 1341da177e4SLinus Torvalds depends on IP_ADVANCED_ROUTER 1351da177e4SLinus Torvalds help 1361da177e4SLinus Torvalds If you say Y here, which is recommended, then the kernel will print 1371da177e4SLinus Torvalds verbose messages regarding the routing, for example warnings about 1381da177e4SLinus Torvalds received packets which look strange and could be evidence of an 1391da177e4SLinus Torvalds attack or a misconfigured system somewhere. The information is 1401da177e4SLinus Torvalds handled by the klogd daemon which is responsible for kernel messages 1411da177e4SLinus Torvalds ("man klogd"). 1421da177e4SLinus Torvalds 143c7066f70SPatrick McHardyconfig IP_ROUTE_CLASSID 144c7066f70SPatrick McHardy bool 145c7066f70SPatrick McHardy 1461da177e4SLinus Torvaldsconfig IP_PNP 1471da177e4SLinus Torvalds bool "IP: kernel level autoconfiguration" 1481da177e4SLinus Torvalds help 1491da177e4SLinus Torvalds This enables automatic configuration of IP addresses of devices and 1501da177e4SLinus Torvalds of the routing table during kernel boot, based on either information 1511da177e4SLinus Torvalds supplied on the kernel command line or by BOOTP or RARP protocols. 1521da177e4SLinus Torvalds You need to say Y only for diskless machines requiring network 1531da177e4SLinus Torvalds access to boot (in which case you want to say Y to "Root file system 1541da177e4SLinus Torvalds on NFS" as well), because all other machines configure the network 1551da177e4SLinus Torvalds in their startup scripts. 1561da177e4SLinus Torvalds 1571da177e4SLinus Torvaldsconfig IP_PNP_DHCP 1581da177e4SLinus Torvalds bool "IP: DHCP support" 1591da177e4SLinus Torvalds depends on IP_PNP 1601da177e4SLinus Torvalds ---help--- 1611da177e4SLinus Torvalds If you want your Linux box to mount its whole root file system (the 1621da177e4SLinus Torvalds one containing the directory /) from some other computer over the 1631da177e4SLinus Torvalds net via NFS and you want the IP address of your computer to be 1641da177e4SLinus Torvalds discovered automatically at boot time using the DHCP protocol (a 1651da177e4SLinus Torvalds special protocol designed for doing this job), say Y here. In case 1661da177e4SLinus Torvalds the boot ROM of your network card was designed for booting Linux and 1671da177e4SLinus Torvalds does DHCP itself, providing all necessary information on the kernel 1681da177e4SLinus Torvalds command line, you can say N here. 1691da177e4SLinus Torvalds 1701da177e4SLinus Torvalds If unsure, say Y. Note that if you want to use DHCP, a DHCP server 1711da177e4SLinus Torvalds must be operating on your network. Read 172dc7a0816SJ. Bruce Fields <file:Documentation/filesystems/nfs/nfsroot.txt> for details. 1731da177e4SLinus Torvalds 1741da177e4SLinus Torvaldsconfig IP_PNP_BOOTP 1751da177e4SLinus Torvalds bool "IP: BOOTP support" 1761da177e4SLinus Torvalds depends on IP_PNP 1771da177e4SLinus Torvalds ---help--- 1781da177e4SLinus Torvalds If you want your Linux box to mount its whole root file system (the 1791da177e4SLinus Torvalds one containing the directory /) from some other computer over the 1801da177e4SLinus Torvalds net via NFS and you want the IP address of your computer to be 1811da177e4SLinus Torvalds discovered automatically at boot time using the BOOTP protocol (a 1821da177e4SLinus Torvalds special protocol designed for doing this job), say Y here. In case 1831da177e4SLinus Torvalds the boot ROM of your network card was designed for booting Linux and 1841da177e4SLinus Torvalds does BOOTP itself, providing all necessary information on the kernel 1851da177e4SLinus Torvalds command line, you can say N here. If unsure, say Y. Note that if you 1861da177e4SLinus Torvalds want to use BOOTP, a BOOTP server must be operating on your network. 187dc7a0816SJ. Bruce Fields Read <file:Documentation/filesystems/nfs/nfsroot.txt> for details. 1881da177e4SLinus Torvalds 1891da177e4SLinus Torvaldsconfig IP_PNP_RARP 1901da177e4SLinus Torvalds bool "IP: RARP support" 1911da177e4SLinus Torvalds depends on IP_PNP 1921da177e4SLinus Torvalds help 1931da177e4SLinus Torvalds If you want your Linux box to mount its whole root file system (the 1941da177e4SLinus Torvalds one containing the directory /) from some other computer over the 1951da177e4SLinus Torvalds net via NFS and you want the IP address of your computer to be 1961da177e4SLinus Torvalds discovered automatically at boot time using the RARP protocol (an 1971da177e4SLinus Torvalds older protocol which is being obsoleted by BOOTP and DHCP), say Y 1981da177e4SLinus Torvalds here. Note that if you want to use RARP, a RARP server must be 1996ded55daSJ. Bruce Fields operating on your network. Read 200dc7a0816SJ. Bruce Fields <file:Documentation/filesystems/nfs/nfsroot.txt> for details. 2011da177e4SLinus Torvalds 2021da177e4SLinus Torvalds# not yet ready.. 2031da177e4SLinus Torvalds# bool ' IP: ARP support' CONFIG_IP_PNP_ARP 2041da177e4SLinus Torvaldsconfig NET_IPIP 2051da177e4SLinus Torvalds tristate "IP: tunneling" 206d2acc347SHerbert Xu select INET_TUNNEL 2071da177e4SLinus Torvalds ---help--- 2081da177e4SLinus Torvalds Tunneling means encapsulating data of one protocol type within 2091da177e4SLinus Torvalds another protocol and sending it over a channel that understands the 2101da177e4SLinus Torvalds encapsulating protocol. This particular tunneling driver implements 2111da177e4SLinus Torvalds encapsulation of IP within IP, which sounds kind of pointless, but 2121da177e4SLinus Torvalds can be useful if you want to make your (or some other) machine 2131da177e4SLinus Torvalds appear on a different network than it physically is, or to use 2141da177e4SLinus Torvalds mobile-IP facilities (allowing laptops to seamlessly move between 2151da177e4SLinus Torvalds networks without changing their IP addresses). 2161da177e4SLinus Torvalds 2171da177e4SLinus Torvalds Saying Y to this option will produce two modules ( = code which can 2181da177e4SLinus Torvalds be inserted in and removed from the running kernel whenever you 2191da177e4SLinus Torvalds want). Most people won't need this and can say N. 2201da177e4SLinus Torvalds 22100959adeSDmitry Kozlovconfig NET_IPGRE_DEMUX 22200959adeSDmitry Kozlov tristate "IP: GRE demultiplexer" 22300959adeSDmitry Kozlov help 22400959adeSDmitry Kozlov This is helper module to demultiplex GRE packets on GRE version field criteria. 22500959adeSDmitry Kozlov Required by ip_gre and pptp modules. 22600959adeSDmitry Kozlov 2271da177e4SLinus Torvaldsconfig NET_IPGRE 2281da177e4SLinus Torvalds tristate "IP: GRE tunnels over IP" 22921a180cdSDavid S. Miller depends on (IPV6 || IPV6=n) && NET_IPGRE_DEMUX 2301da177e4SLinus Torvalds help 2311da177e4SLinus Torvalds Tunneling means encapsulating data of one protocol type within 2321da177e4SLinus Torvalds another protocol and sending it over a channel that understands the 2331da177e4SLinus Torvalds encapsulating protocol. This particular tunneling driver implements 2341da177e4SLinus Torvalds GRE (Generic Routing Encapsulation) and at this time allows 2351da177e4SLinus Torvalds encapsulating of IPv4 or IPv6 over existing IPv4 infrastructure. 2361da177e4SLinus Torvalds This driver is useful if the other endpoint is a Cisco router: Cisco 2371da177e4SLinus Torvalds likes GRE much better than the other Linux tunneling driver ("IP 2381da177e4SLinus Torvalds tunneling" above). In addition, GRE allows multicast redistribution 2391da177e4SLinus Torvalds through the tunnel. 2401da177e4SLinus Torvalds 2411da177e4SLinus Torvaldsconfig NET_IPGRE_BROADCAST 2421da177e4SLinus Torvalds bool "IP: broadcast GRE over IP" 2431da177e4SLinus Torvalds depends on IP_MULTICAST && NET_IPGRE 2441da177e4SLinus Torvalds help 2451da177e4SLinus Torvalds One application of GRE/IP is to construct a broadcast WAN (Wide Area 2461da177e4SLinus Torvalds Network), which looks like a normal Ethernet LAN (Local Area 2471da177e4SLinus Torvalds Network), but can be distributed all over the Internet. If you want 2481da177e4SLinus Torvalds to do that, say Y here and to "IP multicast routing" below. 2491da177e4SLinus Torvalds 2501da177e4SLinus Torvaldsconfig IP_MROUTE 2511da177e4SLinus Torvalds bool "IP: multicast routing" 2521da177e4SLinus Torvalds depends on IP_MULTICAST 2531da177e4SLinus Torvalds help 2541da177e4SLinus Torvalds This is used if you want your machine to act as a router for IP 2551da177e4SLinus Torvalds packets that have several destination addresses. It is needed on the 2561da177e4SLinus Torvalds MBONE, a high bandwidth network on top of the Internet which carries 2571da177e4SLinus Torvalds audio and video broadcasts. In order to do that, you would most 2581da177e4SLinus Torvalds likely run the program mrouted. Information about the multicast 2591da177e4SLinus Torvalds capabilities of the various network cards is contained in 2601da177e4SLinus Torvalds <file:Documentation/networking/multicast.txt>. If you haven't heard 2611da177e4SLinus Torvalds about it, you don't need it. 2621da177e4SLinus Torvalds 263f0ad0860SPatrick McHardyconfig IP_MROUTE_MULTIPLE_TABLES 264f0ad0860SPatrick McHardy bool "IP: multicast policy routing" 26566496d49SPatrick McHardy depends on IP_MROUTE && IP_ADVANCED_ROUTER 266f0ad0860SPatrick McHardy select FIB_RULES 267f0ad0860SPatrick McHardy help 268f0ad0860SPatrick McHardy Normally, a multicast router runs a userspace daemon and decides 269f0ad0860SPatrick McHardy what to do with a multicast packet based on the source and 270f0ad0860SPatrick McHardy destination addresses. If you say Y here, the multicast router 271f0ad0860SPatrick McHardy will also be able to take interfaces and packet marks into 272f0ad0860SPatrick McHardy account and run multiple instances of userspace daemons 273f0ad0860SPatrick McHardy simultaneously, each one handling a single table. 274f0ad0860SPatrick McHardy 275f0ad0860SPatrick McHardy If unsure, say N. 276f0ad0860SPatrick McHardy 2771da177e4SLinus Torvaldsconfig IP_PIMSM_V1 2781da177e4SLinus Torvalds bool "IP: PIM-SM version 1 support" 2791da177e4SLinus Torvalds depends on IP_MROUTE 2801da177e4SLinus Torvalds help 2811da177e4SLinus Torvalds Kernel side support for Sparse Mode PIM (Protocol Independent 2821da177e4SLinus Torvalds Multicast) version 1. This multicast routing protocol is used widely 2831da177e4SLinus Torvalds because Cisco supports it. You need special software to use it 2841da177e4SLinus Torvalds (pimd-v1). Please see <http://netweb.usc.edu/pim/> for more 2851da177e4SLinus Torvalds information about PIM. 2861da177e4SLinus Torvalds 2871da177e4SLinus Torvalds Say Y if you want to use PIM-SM v1. Note that you can say N here if 2881da177e4SLinus Torvalds you just want to use Dense Mode PIM. 2891da177e4SLinus Torvalds 2901da177e4SLinus Torvaldsconfig IP_PIMSM_V2 2911da177e4SLinus Torvalds bool "IP: PIM-SM version 2 support" 2921da177e4SLinus Torvalds depends on IP_MROUTE 2931da177e4SLinus Torvalds help 2941da177e4SLinus Torvalds Kernel side support for Sparse Mode PIM version 2. In order to use 2951da177e4SLinus Torvalds this, you need an experimental routing daemon supporting it (pimd or 2961da177e4SLinus Torvalds gated-5). This routing protocol is not used widely, so say N unless 2971da177e4SLinus Torvalds you want to play with it. 2981da177e4SLinus Torvalds 2991da177e4SLinus Torvaldsconfig ARPD 300e61a4b63STimo Teräs bool "IP: ARP daemon support" 3011da177e4SLinus Torvalds ---help--- 302e61a4b63STimo Teräs The kernel maintains an internal cache which maps IP addresses to 303e61a4b63STimo Teräs hardware addresses on the local network, so that Ethernet/Token Ring/ 304e61a4b63STimo Teräs etc. frames are sent to the proper address on the physical networking 305e61a4b63STimo Teräs layer. Normally, kernel uses the ARP protocol to resolve these 306e61a4b63STimo Teräs mappings. 3071da177e4SLinus Torvalds 308e61a4b63STimo Teräs Saying Y here adds support to have an user space daemon to do this 309e61a4b63STimo Teräs resolution instead. This is useful for implementing an alternate 310e61a4b63STimo Teräs address resolution protocol (e.g. NHRP on mGRE tunnels) and also for 311e61a4b63STimo Teräs testing purposes. 3121da177e4SLinus Torvalds 313e61a4b63STimo Teräs If unsure, say N. 3141da177e4SLinus Torvalds 3151da177e4SLinus Torvaldsconfig SYN_COOKIES 31657f1553eSFlorian Westphal bool "IP: TCP syncookie support" 3171da177e4SLinus Torvalds ---help--- 3181da177e4SLinus Torvalds Normal TCP/IP networking is open to an attack known as "SYN 3191da177e4SLinus Torvalds flooding". This denial-of-service attack prevents legitimate remote 3201da177e4SLinus Torvalds users from being able to connect to your computer during an ongoing 3211da177e4SLinus Torvalds attack and requires very little work from the attacker, who can 3221da177e4SLinus Torvalds operate from anywhere on the Internet. 3231da177e4SLinus Torvalds 3241da177e4SLinus Torvalds SYN cookies provide protection against this type of attack. If you 3251da177e4SLinus Torvalds say Y here, the TCP/IP stack will use a cryptographic challenge 3261da177e4SLinus Torvalds protocol known as "SYN cookies" to enable legitimate users to 3271da177e4SLinus Torvalds continue to connect, even when your machine is under attack. There 3281da177e4SLinus Torvalds is no need for the legitimate users to change their TCP/IP software; 3291da177e4SLinus Torvalds SYN cookies work transparently to them. For technical information 3301da177e4SLinus Torvalds about SYN cookies, check out <http://cr.yp.to/syncookies.html>. 3311da177e4SLinus Torvalds 3321da177e4SLinus Torvalds If you are SYN flooded, the source address reported by the kernel is 3331da177e4SLinus Torvalds likely to have been forged by the attacker; it is only reported as 3341da177e4SLinus Torvalds an aid in tracing the packets to their actual source and should not 3351da177e4SLinus Torvalds be taken as absolute truth. 3361da177e4SLinus Torvalds 3371da177e4SLinus Torvalds SYN cookies may prevent correct error reporting on clients when the 3381da177e4SLinus Torvalds server is really overloaded. If this happens frequently better turn 3391da177e4SLinus Torvalds them off. 3401da177e4SLinus Torvalds 34157f1553eSFlorian Westphal If you say Y here, you can disable SYN cookies at run time by 34257f1553eSFlorian Westphal saying Y to "/proc file system support" and 3431da177e4SLinus Torvalds "Sysctl support" below and executing the command 3441da177e4SLinus Torvalds 34557f1553eSFlorian Westphal echo 0 > /proc/sys/net/ipv4/tcp_syncookies 3461da177e4SLinus Torvalds 34757f1553eSFlorian Westphal after the /proc file system has been mounted. 3481da177e4SLinus Torvalds 3491da177e4SLinus Torvalds If unsure, say N. 3501da177e4SLinus Torvalds 3511da177e4SLinus Torvaldsconfig INET_AH 3521da177e4SLinus Torvalds tristate "IP: AH transformation" 3531da177e4SLinus Torvalds select XFRM 3541da177e4SLinus Torvalds select CRYPTO 3551da177e4SLinus Torvalds select CRYPTO_HMAC 3561da177e4SLinus Torvalds select CRYPTO_MD5 3571da177e4SLinus Torvalds select CRYPTO_SHA1 3581da177e4SLinus Torvalds ---help--- 3591da177e4SLinus Torvalds Support for IPsec AH. 3601da177e4SLinus Torvalds 3611da177e4SLinus Torvalds If unsure, say Y. 3621da177e4SLinus Torvalds 3631da177e4SLinus Torvaldsconfig INET_ESP 3641da177e4SLinus Torvalds tristate "IP: ESP transformation" 3651da177e4SLinus Torvalds select XFRM 3661da177e4SLinus Torvalds select CRYPTO 367ed58dd41SHerbert Xu select CRYPTO_AUTHENC 3681da177e4SLinus Torvalds select CRYPTO_HMAC 3691da177e4SLinus Torvalds select CRYPTO_MD5 3706b7326c8SHerbert Xu select CRYPTO_CBC 3711da177e4SLinus Torvalds select CRYPTO_SHA1 3721da177e4SLinus Torvalds select CRYPTO_DES 3731da177e4SLinus Torvalds ---help--- 3741da177e4SLinus Torvalds Support for IPsec ESP. 3751da177e4SLinus Torvalds 3761da177e4SLinus Torvalds If unsure, say Y. 3771da177e4SLinus Torvalds 3781da177e4SLinus Torvaldsconfig INET_IPCOMP 3791da177e4SLinus Torvalds tristate "IP: IPComp transformation" 380d2acc347SHerbert Xu select INET_XFRM_TUNNEL 3816fccab67SHerbert Xu select XFRM_IPCOMP 3821da177e4SLinus Torvalds ---help--- 3831da177e4SLinus Torvalds Support for IP Payload Compression Protocol (IPComp) (RFC3173), 3841da177e4SLinus Torvalds typically needed for IPsec. 3851da177e4SLinus Torvalds 3861da177e4SLinus Torvalds If unsure, say Y. 3871da177e4SLinus Torvalds 388d2acc347SHerbert Xuconfig INET_XFRM_TUNNEL 389d2acc347SHerbert Xu tristate 390d2acc347SHerbert Xu select INET_TUNNEL 391d2acc347SHerbert Xu default n 3921da177e4SLinus Torvalds 393d2acc347SHerbert Xuconfig INET_TUNNEL 394d2acc347SHerbert Xu tristate 395d2acc347SHerbert Xu default n 3961da177e4SLinus Torvalds 397b59f45d0SHerbert Xuconfig INET_XFRM_MODE_TRANSPORT 398b59f45d0SHerbert Xu tristate "IP: IPsec transport mode" 399b59f45d0SHerbert Xu default y 400b59f45d0SHerbert Xu select XFRM 401b59f45d0SHerbert Xu ---help--- 402b59f45d0SHerbert Xu Support for IPsec transport mode. 403b59f45d0SHerbert Xu 404b59f45d0SHerbert Xu If unsure, say Y. 405b59f45d0SHerbert Xu 406b59f45d0SHerbert Xuconfig INET_XFRM_MODE_TUNNEL 407b59f45d0SHerbert Xu tristate "IP: IPsec tunnel mode" 408b59f45d0SHerbert Xu default y 409b59f45d0SHerbert Xu select XFRM 410b59f45d0SHerbert Xu ---help--- 411b59f45d0SHerbert Xu Support for IPsec tunnel mode. 412b59f45d0SHerbert Xu 413b59f45d0SHerbert Xu If unsure, say Y. 414b59f45d0SHerbert Xu 4150a69452cSDiego Beltramiconfig INET_XFRM_MODE_BEET 4160a69452cSDiego Beltrami tristate "IP: IPsec BEET mode" 4170a69452cSDiego Beltrami default y 4180a69452cSDiego Beltrami select XFRM 4190a69452cSDiego Beltrami ---help--- 4200a69452cSDiego Beltrami Support for IPsec BEET mode. 4210a69452cSDiego Beltrami 4220a69452cSDiego Beltrami If unsure, say Y. 4230a69452cSDiego Beltrami 42471c87e0cSJan-Bernd Themannconfig INET_LRO 425c5d35571SBen Hutchings tristate "Large Receive Offload (ipv4/tcp)" 426bc8a5397SFrans Pop default y 42771c87e0cSJan-Bernd Themann ---help--- 42871c87e0cSJan-Bernd Themann Support for Large Receive Offload (ipv4/tcp). 42971c87e0cSJan-Bernd Themann 43071c87e0cSJan-Bernd Themann If unsure, say Y. 43171c87e0cSJan-Bernd Themann 43217b085eaSArnaldo Carvalho de Meloconfig INET_DIAG 43317b085eaSArnaldo Carvalho de Melo tristate "INET: socket monitoring interface" 4341da177e4SLinus Torvalds default y 4351da177e4SLinus Torvalds ---help--- 43673c1f4a0SArnaldo Carvalho de Melo Support for INET (TCP, DCCP, etc) socket monitoring interface used by 43773c1f4a0SArnaldo Carvalho de Melo native Linux tools such as ss. ss is included in iproute2, currently 438f4b9479dSBaruch Even downloadable at <http://linux-net.osdl.org/index.php/Iproute2>. 4391da177e4SLinus Torvalds 4401da177e4SLinus Torvalds If unsure, say Y. 4411da177e4SLinus Torvalds 44217b085eaSArnaldo Carvalho de Meloconfig INET_TCP_DIAG 44317b085eaSArnaldo Carvalho de Melo depends on INET_DIAG 44417b085eaSArnaldo Carvalho de Melo def_tristate INET_DIAG 44517b085eaSArnaldo Carvalho de Melo 4463d2573f7SStephen Hemmingermenuconfig TCP_CONG_ADVANCED 447a6484045SDavid S. Miller bool "TCP: advanced congestion control" 448a6484045SDavid S. Miller ---help--- 449a6484045SDavid S. Miller Support for selection of various TCP congestion control 450a6484045SDavid S. Miller modules. 451a6484045SDavid S. Miller 452a6484045SDavid S. Miller Nearly all users can safely say no here, and a safe default 453597811ecSStephen Hemminger selection will be made (CUBIC with new Reno as a fallback). 454a6484045SDavid S. Miller 455a6484045SDavid S. Miller If unsure, say N. 456a6484045SDavid S. Miller 4573d2573f7SStephen Hemmingerif TCP_CONG_ADVANCED 45883803034SStephen Hemminger 45983803034SStephen Hemmingerconfig TCP_CONG_BIC 46083803034SStephen Hemminger tristate "Binary Increase Congestion (BIC) control" 461597811ecSStephen Hemminger default m 46283803034SStephen Hemminger ---help--- 46383803034SStephen Hemminger BIC-TCP is a sender-side only change that ensures a linear RTT 46483803034SStephen Hemminger fairness under large windows while offering both scalability and 46583803034SStephen Hemminger bounded TCP-friendliness. The protocol combines two schemes 46683803034SStephen Hemminger called additive increase and binary search increase. When the 46783803034SStephen Hemminger congestion window is large, additive increase with a large 46883803034SStephen Hemminger increment ensures linear RTT fairness as well as good 46983803034SStephen Hemminger scalability. Under small congestion windows, binary search 47083803034SStephen Hemminger increase provides TCP friendliness. 47183803034SStephen Hemminger See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/ 47283803034SStephen Hemminger 473df3271f3SStephen Hemmingerconfig TCP_CONG_CUBIC 474df3271f3SStephen Hemminger tristate "CUBIC TCP" 475597811ecSStephen Hemminger default y 476df3271f3SStephen Hemminger ---help--- 477df3271f3SStephen Hemminger This is version 2.0 of BIC-TCP which uses a cubic growth function 478df3271f3SStephen Hemminger among other techniques. 479df3271f3SStephen Hemminger See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/cubic-paper.pdf 480df3271f3SStephen Hemminger 48187270762SStephen Hemmingerconfig TCP_CONG_WESTWOOD 48287270762SStephen Hemminger tristate "TCP Westwood+" 48387270762SStephen Hemminger default m 48487270762SStephen Hemminger ---help--- 48587270762SStephen Hemminger TCP Westwood+ is a sender-side only modification of the TCP Reno 48687270762SStephen Hemminger protocol stack that optimizes the performance of TCP congestion 48787270762SStephen Hemminger control. It is based on end-to-end bandwidth estimation to set 48887270762SStephen Hemminger congestion window and slow start threshold after a congestion 48987270762SStephen Hemminger episode. Using this estimation, TCP Westwood+ adaptively sets a 49087270762SStephen Hemminger slow start threshold and a congestion window which takes into 49187270762SStephen Hemminger account the bandwidth used at the time congestion is experienced. 49287270762SStephen Hemminger TCP Westwood+ significantly increases fairness wrt TCP Reno in 49387270762SStephen Hemminger wired networks and throughput over wireless links. 49487270762SStephen Hemminger 495a7868ea6SBaruch Evenconfig TCP_CONG_HTCP 496a7868ea6SBaruch Even tristate "H-TCP" 497a7868ea6SBaruch Even default m 498a7868ea6SBaruch Even ---help--- 499a7868ea6SBaruch Even H-TCP is a send-side only modifications of the TCP Reno 500a7868ea6SBaruch Even protocol stack that optimizes the performance of TCP 501a7868ea6SBaruch Even congestion control for high speed network links. It uses a 502a7868ea6SBaruch Even modeswitch to change the alpha and beta parameters of TCP Reno 503a7868ea6SBaruch Even based on network conditions and in a way so as to be fair with 504a7868ea6SBaruch Even other Reno and H-TCP flows. 505a7868ea6SBaruch Even 506a628d29bSJohn Heffnerconfig TCP_CONG_HSTCP 507a628d29bSJohn Heffner tristate "High Speed TCP" 5086a2e9b73SSam Ravnborg depends on EXPERIMENTAL 509a628d29bSJohn Heffner default n 510a628d29bSJohn Heffner ---help--- 511a628d29bSJohn Heffner Sally Floyd's High Speed TCP (RFC 3649) congestion control. 512a628d29bSJohn Heffner A modification to TCP's congestion control mechanism for use 513a628d29bSJohn Heffner with large congestion windows. A table indicates how much to 514a628d29bSJohn Heffner increase the congestion window by when an ACK is received. 515a628d29bSJohn Heffner For more detail see http://www.icir.org/floyd/hstcp.html 516a628d29bSJohn Heffner 517835b3f0cSDaniele Lacameraconfig TCP_CONG_HYBLA 518835b3f0cSDaniele Lacamera tristate "TCP-Hybla congestion control algorithm" 5196a2e9b73SSam Ravnborg depends on EXPERIMENTAL 520835b3f0cSDaniele Lacamera default n 521835b3f0cSDaniele Lacamera ---help--- 522835b3f0cSDaniele Lacamera TCP-Hybla is a sender-side only change that eliminates penalization of 523835b3f0cSDaniele Lacamera long-RTT, large-bandwidth connections, like when satellite legs are 52444c09201SMatt LaPlante involved, especially when sharing a common bottleneck with normal 525835b3f0cSDaniele Lacamera terrestrial connections. 526835b3f0cSDaniele Lacamera 527b87d8561SStephen Hemmingerconfig TCP_CONG_VEGAS 528b87d8561SStephen Hemminger tristate "TCP Vegas" 5296a2e9b73SSam Ravnborg depends on EXPERIMENTAL 530b87d8561SStephen Hemminger default n 531b87d8561SStephen Hemminger ---help--- 532b87d8561SStephen Hemminger TCP Vegas is a sender-side only change to TCP that anticipates 533b87d8561SStephen Hemminger the onset of congestion by estimating the bandwidth. TCP Vegas 534b87d8561SStephen Hemminger adjusts the sending rate by modifying the congestion 535b87d8561SStephen Hemminger window. TCP Vegas should provide less packet loss, but it is 536b87d8561SStephen Hemminger not as aggressive as TCP Reno. 537b87d8561SStephen Hemminger 5380e57976bSJohn Heffnerconfig TCP_CONG_SCALABLE 5390e57976bSJohn Heffner tristate "Scalable TCP" 5406a2e9b73SSam Ravnborg depends on EXPERIMENTAL 5410e57976bSJohn Heffner default n 5420e57976bSJohn Heffner ---help--- 5430e57976bSJohn Heffner Scalable TCP is a sender-side only change to TCP which uses a 5440e57976bSJohn Heffner MIMD congestion control algorithm which has some nice scaling 5450e57976bSJohn Heffner properties, though is known to have fairness issues. 546f4b9479dSBaruch Even See http://www.deneholme.net/tom/scalable/ 547a7868ea6SBaruch Even 5487c106d7eSWong Hoi Sing Edisonconfig TCP_CONG_LP 5497c106d7eSWong Hoi Sing Edison tristate "TCP Low Priority" 5507c106d7eSWong Hoi Sing Edison depends on EXPERIMENTAL 5517c106d7eSWong Hoi Sing Edison default n 5527c106d7eSWong Hoi Sing Edison ---help--- 5537c106d7eSWong Hoi Sing Edison TCP Low Priority (TCP-LP), a distributed algorithm whose goal is 554cab00891SMatt LaPlante to utilize only the excess network bandwidth as compared to the 5557c106d7eSWong Hoi Sing Edison ``fair share`` of bandwidth as targeted by TCP. 5567c106d7eSWong Hoi Sing Edison See http://www-ece.rice.edu/networks/TCP-LP/ 5577c106d7eSWong Hoi Sing Edison 55876f10177SBin Zhouconfig TCP_CONG_VENO 55976f10177SBin Zhou tristate "TCP Veno" 56076f10177SBin Zhou depends on EXPERIMENTAL 56176f10177SBin Zhou default n 56276f10177SBin Zhou ---help--- 56376f10177SBin Zhou TCP Veno is a sender-side only enhancement of TCP to obtain better 56476f10177SBin Zhou throughput over wireless networks. TCP Veno makes use of state 56576f10177SBin Zhou distinguishing to circumvent the difficult judgment of the packet loss 56676f10177SBin Zhou type. TCP Veno cuts down less congestion window in response to random 56776f10177SBin Zhou loss packets. 568631dd1a8SJustin P. Mattock See <http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=1177186> 56976f10177SBin Zhou 5705ef81475SAngelo P. Castellaniconfig TCP_CONG_YEAH 5715ef81475SAngelo P. Castellani tristate "YeAH TCP" 5725ef81475SAngelo P. Castellani depends on EXPERIMENTAL 5732ff011efSDavid S. Miller select TCP_CONG_VEGAS 5745ef81475SAngelo P. Castellani default n 5755ef81475SAngelo P. Castellani ---help--- 5765ef81475SAngelo P. Castellani YeAH-TCP is a sender-side high-speed enabled TCP congestion control 5775ef81475SAngelo P. Castellani algorithm, which uses a mixed loss/delay approach to compute the 5785ef81475SAngelo P. Castellani congestion window. It's design goals target high efficiency, 5795ef81475SAngelo P. Castellani internal, RTT and Reno fairness, resilience to link loss while 5805ef81475SAngelo P. Castellani keeping network elements load as low as possible. 5815ef81475SAngelo P. Castellani 5825ef81475SAngelo P. Castellani For further details look here: 5835ef81475SAngelo P. Castellani http://wil.cs.caltech.edu/pfldnet2007/paper/YeAH_TCP.pdf 5845ef81475SAngelo P. Castellani 585c462238dSStephen Hemmingerconfig TCP_CONG_ILLINOIS 586c462238dSStephen Hemminger tristate "TCP Illinois" 587c462238dSStephen Hemminger depends on EXPERIMENTAL 588c462238dSStephen Hemminger default n 589c462238dSStephen Hemminger ---help--- 59001dd2fbfSMatt LaPlante TCP-Illinois is a sender-side modification of TCP Reno for 591c462238dSStephen Hemminger high speed long delay links. It uses round-trip-time to 592c462238dSStephen Hemminger adjust the alpha and beta parameters to achieve a higher average 593c462238dSStephen Hemminger throughput and maintain fairness. 594c462238dSStephen Hemminger 595c462238dSStephen Hemminger For further details see: 596c462238dSStephen Hemminger http://www.ews.uiuc.edu/~shaoliu/tcpillinois/index.html 597c462238dSStephen Hemminger 5983d2573f7SStephen Hemmingerchoice 5993d2573f7SStephen Hemminger prompt "Default TCP congestion control" 600597811ecSStephen Hemminger default DEFAULT_CUBIC 6013d2573f7SStephen Hemminger help 6023d2573f7SStephen Hemminger Select the TCP congestion control that will be used by default 6033d2573f7SStephen Hemminger for all connections. 6043d2573f7SStephen Hemminger 6053d2573f7SStephen Hemminger config DEFAULT_BIC 6063d2573f7SStephen Hemminger bool "Bic" if TCP_CONG_BIC=y 6073d2573f7SStephen Hemminger 6083d2573f7SStephen Hemminger config DEFAULT_CUBIC 6093d2573f7SStephen Hemminger bool "Cubic" if TCP_CONG_CUBIC=y 6103d2573f7SStephen Hemminger 6113d2573f7SStephen Hemminger config DEFAULT_HTCP 6123d2573f7SStephen Hemminger bool "Htcp" if TCP_CONG_HTCP=y 6133d2573f7SStephen Hemminger 614dd2acaa7SJan Engelhardt config DEFAULT_HYBLA 615dd2acaa7SJan Engelhardt bool "Hybla" if TCP_CONG_HYBLA=y 616dd2acaa7SJan Engelhardt 6173d2573f7SStephen Hemminger config DEFAULT_VEGAS 6183d2573f7SStephen Hemminger bool "Vegas" if TCP_CONG_VEGAS=y 6193d2573f7SStephen Hemminger 6206ce1a6dfSJan Engelhardt config DEFAULT_VENO 6216ce1a6dfSJan Engelhardt bool "Veno" if TCP_CONG_VENO=y 6226ce1a6dfSJan Engelhardt 6233d2573f7SStephen Hemminger config DEFAULT_WESTWOOD 6243d2573f7SStephen Hemminger bool "Westwood" if TCP_CONG_WESTWOOD=y 6253d2573f7SStephen Hemminger 6263d2573f7SStephen Hemminger config DEFAULT_RENO 6273d2573f7SStephen Hemminger bool "Reno" 6283d2573f7SStephen Hemminger 6293d2573f7SStephen Hemmingerendchoice 6303d2573f7SStephen Hemminger 6313d2573f7SStephen Hemmingerendif 63283803034SStephen Hemminger 633597811ecSStephen Hemmingerconfig TCP_CONG_CUBIC 6346c360767SDavid S. Miller tristate 635a6484045SDavid S. Miller depends on !TCP_CONG_ADVANCED 636a6484045SDavid S. Miller default y 637a6484045SDavid S. Miller 6383d2573f7SStephen Hemmingerconfig DEFAULT_TCP_CONG 6393d2573f7SStephen Hemminger string 6403d2573f7SStephen Hemminger default "bic" if DEFAULT_BIC 6413d2573f7SStephen Hemminger default "cubic" if DEFAULT_CUBIC 6423d2573f7SStephen Hemminger default "htcp" if DEFAULT_HTCP 643dd2acaa7SJan Engelhardt default "hybla" if DEFAULT_HYBLA 6443d2573f7SStephen Hemminger default "vegas" if DEFAULT_VEGAS 6453d2573f7SStephen Hemminger default "westwood" if DEFAULT_WESTWOOD 6466ce1a6dfSJan Engelhardt default "veno" if DEFAULT_VENO 6473d2573f7SStephen Hemminger default "reno" if DEFAULT_RENO 648597811ecSStephen Hemminger default "cubic" 6493d2573f7SStephen Hemminger 650cfb6eeb4SYOSHIFUJI Hideakiconfig TCP_MD5SIG 651cfb6eeb4SYOSHIFUJI Hideaki bool "TCP: MD5 Signature Option support (RFC2385) (EXPERIMENTAL)" 652cfb6eeb4SYOSHIFUJI Hideaki depends on EXPERIMENTAL 653cfb6eeb4SYOSHIFUJI Hideaki select CRYPTO 654cfb6eeb4SYOSHIFUJI Hideaki select CRYPTO_MD5 655cfb6eeb4SYOSHIFUJI Hideaki ---help--- 6563dde6ad8SDavid Sterba RFC2385 specifies a method of giving MD5 protection to TCP sessions. 657cfb6eeb4SYOSHIFUJI Hideaki Its main (only?) use is to protect BGP sessions between core routers 658cfb6eeb4SYOSHIFUJI Hideaki on the Internet. 659cfb6eeb4SYOSHIFUJI Hideaki 660cfb6eeb4SYOSHIFUJI Hideaki If unsure, say N. 661