11da177e4SLinus Torvalds# 21da177e4SLinus Torvalds# Network configuration 31da177e4SLinus Torvalds# 41da177e4SLinus Torvalds 5d5950b43SSam Ravnborgmenu "Networking" 61da177e4SLinus Torvalds 71da177e4SLinus Torvaldsconfig NET 81da177e4SLinus Torvalds bool "Networking support" 91da177e4SLinus Torvalds ---help--- 101da177e4SLinus Torvalds Unless you really know what you are doing, you should say Y here. 111da177e4SLinus Torvalds The reason is that some programs need kernel networking support even 121da177e4SLinus Torvalds when running on a stand-alone machine that isn't connected to any 13d5950b43SSam Ravnborg other computer. 14d5950b43SSam Ravnborg 15d5950b43SSam Ravnborg If you are upgrading from an older kernel, you 161da177e4SLinus Torvalds should consider updating your networking tools too because changes 171da177e4SLinus Torvalds in the kernel and the tools often go hand in hand. The tools are 181da177e4SLinus Torvalds contained in the package net-tools, the location and version number 191da177e4SLinus Torvalds of which are given in <file:Documentation/Changes>. 201da177e4SLinus Torvalds 211da177e4SLinus Torvalds For a general introduction to Linux networking, it is highly 221da177e4SLinus Torvalds recommended to read the NET-HOWTO, available from 231da177e4SLinus Torvalds <http://www.tldp.org/docs.html#howto>. 241da177e4SLinus Torvalds 256a2e9b73SSam Ravnborg# Make sure that all config symbols are dependent on NET 266a2e9b73SSam Ravnborgif NET 276a2e9b73SSam Ravnborg 281da177e4SLinus Torvaldsmenu "Networking options" 291da177e4SLinus Torvalds 306a2e9b73SSam Ravnborgsource "net/packet/Kconfig" 316a2e9b73SSam Ravnborgsource "net/unix/Kconfig" 326a2e9b73SSam Ravnborgsource "net/xfrm/Kconfig" 331da177e4SLinus Torvalds 341da177e4SLinus Torvaldsconfig INET 351da177e4SLinus Torvalds bool "TCP/IP networking" 361da177e4SLinus Torvalds ---help--- 371da177e4SLinus Torvalds These are the protocols used on the Internet and on most local 381da177e4SLinus Torvalds Ethernets. It is highly recommended to say Y here (this will enlarge 391da177e4SLinus Torvalds your kernel by about 144 KB), since some programs (e.g. the X window 401da177e4SLinus Torvalds system) use TCP/IP even if your machine is not connected to any 411da177e4SLinus Torvalds other computer. You will get the so-called loopback device which 421da177e4SLinus Torvalds allows you to ping yourself (great fun, that!). 431da177e4SLinus Torvalds 441da177e4SLinus Torvalds For an excellent introduction to Linux networking, please read the 451da177e4SLinus Torvalds Linux Networking HOWTO, available from 461da177e4SLinus Torvalds <http://www.tldp.org/docs.html#howto>. 471da177e4SLinus Torvalds 481da177e4SLinus Torvalds If you say Y here and also to "/proc file system support" and 491da177e4SLinus Torvalds "Sysctl support" below, you can change various aspects of the 501da177e4SLinus Torvalds behavior of the TCP/IP code by writing to the (virtual) files in 511da177e4SLinus Torvalds /proc/sys/net/ipv4/*; the options are explained in the file 521da177e4SLinus Torvalds <file:Documentation/networking/ip-sysctl.txt>. 531da177e4SLinus Torvalds 541da177e4SLinus Torvalds Short answer: say Y. 551da177e4SLinus Torvalds 566a2e9b73SSam Ravnborgif INET 571da177e4SLinus Torvaldssource "net/ipv4/Kconfig" 581da177e4SLinus Torvaldssource "net/ipv6/Kconfig" 591da177e4SLinus Torvalds 606a2e9b73SSam Ravnborgendif # if INET 616a2e9b73SSam Ravnborg 621da177e4SLinus Torvaldsmenuconfig NETFILTER 631da177e4SLinus Torvalds bool "Network packet filtering (replaces ipchains)" 641da177e4SLinus Torvalds ---help--- 651da177e4SLinus Torvalds Netfilter is a framework for filtering and mangling network packets 661da177e4SLinus Torvalds that pass through your Linux box. 671da177e4SLinus Torvalds 681da177e4SLinus Torvalds The most common use of packet filtering is to run your Linux box as 691da177e4SLinus Torvalds a firewall protecting a local network from the Internet. The type of 701da177e4SLinus Torvalds firewall provided by this kernel support is called a "packet 711da177e4SLinus Torvalds filter", which means that it can reject individual network packets 721da177e4SLinus Torvalds based on type, source, destination etc. The other kind of firewall, 731da177e4SLinus Torvalds a "proxy-based" one, is more secure but more intrusive and more 741da177e4SLinus Torvalds bothersome to set up; it inspects the network traffic much more 751da177e4SLinus Torvalds closely, modifies it and has knowledge about the higher level 761da177e4SLinus Torvalds protocols, which a packet filter lacks. Moreover, proxy-based 771da177e4SLinus Torvalds firewalls often require changes to the programs running on the local 781da177e4SLinus Torvalds clients. Proxy-based firewalls don't need support by the kernel, but 791da177e4SLinus Torvalds they are often combined with a packet filter, which only works if 801da177e4SLinus Torvalds you say Y here. 811da177e4SLinus Torvalds 821da177e4SLinus Torvalds You should also say Y here if you intend to use your Linux box as 831da177e4SLinus Torvalds the gateway to the Internet for a local network of machines without 841da177e4SLinus Torvalds globally valid IP addresses. This is called "masquerading": if one 851da177e4SLinus Torvalds of the computers on your local network wants to send something to 861da177e4SLinus Torvalds the outside, your box can "masquerade" as that computer, i.e. it 871da177e4SLinus Torvalds forwards the traffic to the intended outside destination, but 881da177e4SLinus Torvalds modifies the packets to make it look like they came from the 891da177e4SLinus Torvalds firewall box itself. It works both ways: if the outside host 901da177e4SLinus Torvalds replies, the Linux box will silently forward the traffic to the 911da177e4SLinus Torvalds correct local computer. This way, the computers on your local net 921da177e4SLinus Torvalds are completely invisible to the outside world, even though they can 931da177e4SLinus Torvalds reach the outside and can receive replies. It is even possible to 941da177e4SLinus Torvalds run globally visible servers from within a masqueraded local network 951da177e4SLinus Torvalds using a mechanism called portforwarding. Masquerading is also often 961da177e4SLinus Torvalds called NAT (Network Address Translation). 971da177e4SLinus Torvalds 981da177e4SLinus Torvalds Another use of Netfilter is in transparent proxying: if a machine on 991da177e4SLinus Torvalds the local network tries to connect to an outside host, your Linux 1001da177e4SLinus Torvalds box can transparently forward the traffic to a local server, 1011da177e4SLinus Torvalds typically a caching proxy server. 1021da177e4SLinus Torvalds 1031da177e4SLinus Torvalds Yet another use of Netfilter is building a bridging firewall. Using 1041da177e4SLinus Torvalds a bridge with Network packet filtering enabled makes iptables "see" 1051da177e4SLinus Torvalds the bridged traffic. For filtering on the lower network and Ethernet 1061da177e4SLinus Torvalds protocols over the bridge, use ebtables (under bridge netfilter 1071da177e4SLinus Torvalds configuration). 1081da177e4SLinus Torvalds 1091da177e4SLinus Torvalds Various modules exist for netfilter which replace the previous 1101da177e4SLinus Torvalds masquerading (ipmasqadm), packet filtering (ipchains), transparent 1111da177e4SLinus Torvalds proxying, and portforwarding mechanisms. Please see 1121da177e4SLinus Torvalds <file:Documentation/Changes> under "iptables" for the location of 1131da177e4SLinus Torvalds these packages. 1141da177e4SLinus Torvalds 1151da177e4SLinus Torvalds Make sure to say N to "Fast switching" below if you intend to say Y 1161da177e4SLinus Torvalds here, as Fast switching currently bypasses netfilter. 1171da177e4SLinus Torvalds 1181da177e4SLinus Torvalds Chances are that you should say Y here if you compile a kernel which 1191da177e4SLinus Torvalds will run as a router and N for regular hosts. If unsure, say N. 1201da177e4SLinus Torvalds 1211da177e4SLinus Torvaldsif NETFILTER 1221da177e4SLinus Torvalds 1231da177e4SLinus Torvaldsconfig NETFILTER_DEBUG 1241da177e4SLinus Torvalds bool "Network packet filtering debugging" 1251da177e4SLinus Torvalds depends on NETFILTER 1261da177e4SLinus Torvalds help 1271da177e4SLinus Torvalds You can say Y here if you want to get additional messages useful in 1281da177e4SLinus Torvalds debugging the netfilter code. 1291da177e4SLinus Torvalds 1301da177e4SLinus Torvaldsconfig BRIDGE_NETFILTER 1311da177e4SLinus Torvalds bool "Bridged IP/ARP packets filtering" 1321da177e4SLinus Torvalds depends on BRIDGE && NETFILTER && INET 1331da177e4SLinus Torvalds default y 1341da177e4SLinus Torvalds ---help--- 1351da177e4SLinus Torvalds Enabling this option will let arptables resp. iptables see bridged 1361da177e4SLinus Torvalds ARP resp. IP traffic. If you want a bridging firewall, you probably 1371da177e4SLinus Torvalds want this option enabled. 1381da177e4SLinus Torvalds Enabling or disabling this option doesn't enable or disable 1391da177e4SLinus Torvalds ebtables. 1401da177e4SLinus Torvalds 1411da177e4SLinus Torvalds If unsure, say N. 1421da177e4SLinus Torvalds 1439eb0eec7SHarald Weltesource "net/netfilter/Kconfig" 1441da177e4SLinus Torvaldssource "net/ipv4/netfilter/Kconfig" 1451da177e4SLinus Torvaldssource "net/ipv6/netfilter/Kconfig" 1461da177e4SLinus Torvaldssource "net/decnet/netfilter/Kconfig" 1471da177e4SLinus Torvaldssource "net/bridge/netfilter/Kconfig" 1481da177e4SLinus Torvalds 1491da177e4SLinus Torvaldsendif 1501da177e4SLinus Torvalds 1517c657876SArnaldo Carvalho de Melosource "net/dccp/Kconfig" 1521da177e4SLinus Torvaldssource "net/sctp/Kconfig" 1531e63e681SPer Lidensource "net/tipc/Kconfig" 1546a2e9b73SSam Ravnborgsource "net/atm/Kconfig" 1556a2e9b73SSam Ravnborgsource "net/bridge/Kconfig" 1566a2e9b73SSam Ravnborgsource "net/8021q/Kconfig" 1571da177e4SLinus Torvaldssource "net/decnet/Kconfig" 1581da177e4SLinus Torvaldssource "net/llc/Kconfig" 1591da177e4SLinus Torvaldssource "net/ipx/Kconfig" 1601da177e4SLinus Torvaldssource "drivers/net/appletalk/Kconfig" 1616a2e9b73SSam Ravnborgsource "net/x25/Kconfig" 1626a2e9b73SSam Ravnborgsource "net/lapb/Kconfig" 1631da177e4SLinus Torvalds 1641da177e4SLinus Torvaldsconfig NET_DIVERT 1651da177e4SLinus Torvalds bool "Frame Diverter (EXPERIMENTAL)" 1661da177e4SLinus Torvalds depends on EXPERIMENTAL 1671da177e4SLinus Torvalds ---help--- 1681da177e4SLinus Torvalds The Frame Diverter allows you to divert packets from the 1691da177e4SLinus Torvalds network, that are not aimed at the interface receiving it (in 1701da177e4SLinus Torvalds promisc. mode). Typically, a Linux box setup as an Ethernet bridge 1711da177e4SLinus Torvalds with the Frames Diverter on, can do some *really* transparent www 1721da177e4SLinus Torvalds caching using a Squid proxy for example. 1731da177e4SLinus Torvalds 1741da177e4SLinus Torvalds This is very useful when you don't want to change your router's 1751da177e4SLinus Torvalds config (or if you simply don't have access to it). 1761da177e4SLinus Torvalds 1771da177e4SLinus Torvalds The other possible usages of diverting Ethernet Frames are 1781da177e4SLinus Torvalds numberous: 1791da177e4SLinus Torvalds - reroute smtp traffic to another interface 1801da177e4SLinus Torvalds - traffic-shape certain network streams 1811da177e4SLinus Torvalds - transparently proxy smtp connections 1821da177e4SLinus Torvalds - etc... 1831da177e4SLinus Torvalds 1841da177e4SLinus Torvalds For more informations, please refer to: 1851da177e4SLinus Torvalds <http://diverter.sourceforge.net/> 1861da177e4SLinus Torvalds <http://perso.wanadoo.fr/magpie/EtherDivert.html> 1871da177e4SLinus Torvalds 1881da177e4SLinus Torvalds If unsure, say N. 1891da177e4SLinus Torvalds 1906a2e9b73SSam Ravnborgsource "net/econet/Kconfig" 1916a2e9b73SSam Ravnborgsource "net/wanrouter/Kconfig" 1921da177e4SLinus Torvaldssource "net/sched/Kconfig" 1931da177e4SLinus Torvalds 1941da177e4SLinus Torvaldsmenu "Network testing" 1951da177e4SLinus Torvalds 1961da177e4SLinus Torvaldsconfig NET_PKTGEN 1971da177e4SLinus Torvalds tristate "Packet Generator (USE WITH CAUTION)" 1981da177e4SLinus Torvalds depends on PROC_FS 1991da177e4SLinus Torvalds ---help--- 2001da177e4SLinus Torvalds This module will inject preconfigured packets, at a configurable 2011da177e4SLinus Torvalds rate, out of a given interface. It is used for network interface 2021da177e4SLinus Torvalds stress testing and performance analysis. If you don't understand 2031da177e4SLinus Torvalds what was just said, you don't need it: say N. 2041da177e4SLinus Torvalds 2051da177e4SLinus Torvalds Documentation on how to use the packet generator can be found 2061da177e4SLinus Torvalds at <file:Documentation/networking/pktgen.txt>. 2071da177e4SLinus Torvalds 2081da177e4SLinus Torvalds To compile this code as a module, choose M here: the 2091da177e4SLinus Torvalds module will be called pktgen. 2101da177e4SLinus Torvalds 2111da177e4SLinus Torvaldsendmenu 2121da177e4SLinus Torvalds 2131da177e4SLinus Torvaldsendmenu 2141da177e4SLinus Torvalds 2151da177e4SLinus Torvaldssource "net/ax25/Kconfig" 2161da177e4SLinus Torvaldssource "net/irda/Kconfig" 2171da177e4SLinus Torvaldssource "net/bluetooth/Kconfig" 218b453872cSJeff Garziksource "net/ieee80211/Kconfig" 219b453872cSJeff Garzik 220d86b5e0eSAdrian Bunkconfig WIRELESS_EXT 221d86b5e0eSAdrian Bunk bool 222d86b5e0eSAdrian Bunk 2236a2e9b73SSam Ravnborgendif # if NET 224d5950b43SSam Ravnborgendmenu # Networking 2251da177e4SLinus Torvalds 226