1# 2# Network configuration 3# 4 5menu "Networking" 6 7config NET 8 bool "Networking support" 9 ---help--- 10 Unless you really know what you are doing, you should say Y here. 11 The reason is that some programs need kernel networking support even 12 when running on a stand-alone machine that isn't connected to any 13 other computer. 14 15 If you are upgrading from an older kernel, you 16 should consider updating your networking tools too because changes 17 in the kernel and the tools often go hand in hand. The tools are 18 contained in the package net-tools, the location and version number 19 of which are given in <file:Documentation/Changes>. 20 21 For a general introduction to Linux networking, it is highly 22 recommended to read the NET-HOWTO, available from 23 <http://www.tldp.org/docs.html#howto>. 24 25# Make sure that all config symbols are dependent on NET 26if NET 27 28menu "Networking options" 29 30source "net/packet/Kconfig" 31source "net/unix/Kconfig" 32source "net/xfrm/Kconfig" 33 34config INET 35 bool "TCP/IP networking" 36 ---help--- 37 These are the protocols used on the Internet and on most local 38 Ethernets. It is highly recommended to say Y here (this will enlarge 39 your kernel by about 144 KB), since some programs (e.g. the X window 40 system) use TCP/IP even if your machine is not connected to any 41 other computer. You will get the so-called loopback device which 42 allows you to ping yourself (great fun, that!). 43 44 For an excellent introduction to Linux networking, please read the 45 Linux Networking HOWTO, available from 46 <http://www.tldp.org/docs.html#howto>. 47 48 If you say Y here and also to "/proc file system support" and 49 "Sysctl support" below, you can change various aspects of the 50 behavior of the TCP/IP code by writing to the (virtual) files in 51 /proc/sys/net/ipv4/*; the options are explained in the file 52 <file:Documentation/networking/ip-sysctl.txt>. 53 54 Short answer: say Y. 55 56if INET 57source "net/ipv4/Kconfig" 58source "net/ipv6/Kconfig" 59 60endif # if INET 61 62menuconfig NETFILTER 63 bool "Network packet filtering (replaces ipchains)" 64 ---help--- 65 Netfilter is a framework for filtering and mangling network packets 66 that pass through your Linux box. 67 68 The most common use of packet filtering is to run your Linux box as 69 a firewall protecting a local network from the Internet. The type of 70 firewall provided by this kernel support is called a "packet 71 filter", which means that it can reject individual network packets 72 based on type, source, destination etc. The other kind of firewall, 73 a "proxy-based" one, is more secure but more intrusive and more 74 bothersome to set up; it inspects the network traffic much more 75 closely, modifies it and has knowledge about the higher level 76 protocols, which a packet filter lacks. Moreover, proxy-based 77 firewalls often require changes to the programs running on the local 78 clients. Proxy-based firewalls don't need support by the kernel, but 79 they are often combined with a packet filter, which only works if 80 you say Y here. 81 82 You should also say Y here if you intend to use your Linux box as 83 the gateway to the Internet for a local network of machines without 84 globally valid IP addresses. This is called "masquerading": if one 85 of the computers on your local network wants to send something to 86 the outside, your box can "masquerade" as that computer, i.e. it 87 forwards the traffic to the intended outside destination, but 88 modifies the packets to make it look like they came from the 89 firewall box itself. It works both ways: if the outside host 90 replies, the Linux box will silently forward the traffic to the 91 correct local computer. This way, the computers on your local net 92 are completely invisible to the outside world, even though they can 93 reach the outside and can receive replies. It is even possible to 94 run globally visible servers from within a masqueraded local network 95 using a mechanism called portforwarding. Masquerading is also often 96 called NAT (Network Address Translation). 97 98 Another use of Netfilter is in transparent proxying: if a machine on 99 the local network tries to connect to an outside host, your Linux 100 box can transparently forward the traffic to a local server, 101 typically a caching proxy server. 102 103 Yet another use of Netfilter is building a bridging firewall. Using 104 a bridge with Network packet filtering enabled makes iptables "see" 105 the bridged traffic. For filtering on the lower network and Ethernet 106 protocols over the bridge, use ebtables (under bridge netfilter 107 configuration). 108 109 Various modules exist for netfilter which replace the previous 110 masquerading (ipmasqadm), packet filtering (ipchains), transparent 111 proxying, and portforwarding mechanisms. Please see 112 <file:Documentation/Changes> under "iptables" for the location of 113 these packages. 114 115 Make sure to say N to "Fast switching" below if you intend to say Y 116 here, as Fast switching currently bypasses netfilter. 117 118 Chances are that you should say Y here if you compile a kernel which 119 will run as a router and N for regular hosts. If unsure, say N. 120 121if NETFILTER 122 123config NETFILTER_DEBUG 124 bool "Network packet filtering debugging" 125 depends on NETFILTER 126 help 127 You can say Y here if you want to get additional messages useful in 128 debugging the netfilter code. 129 130config BRIDGE_NETFILTER 131 bool "Bridged IP/ARP packets filtering" 132 depends on BRIDGE && NETFILTER && INET 133 default y 134 ---help--- 135 Enabling this option will let arptables resp. iptables see bridged 136 ARP resp. IP traffic. If you want a bridging firewall, you probably 137 want this option enabled. 138 Enabling or disabling this option doesn't enable or disable 139 ebtables. 140 141 If unsure, say N. 142 143source "net/netfilter/Kconfig" 144source "net/ipv4/netfilter/Kconfig" 145source "net/ipv6/netfilter/Kconfig" 146source "net/decnet/netfilter/Kconfig" 147source "net/bridge/netfilter/Kconfig" 148 149endif 150 151source "net/dccp/Kconfig" 152source "net/sctp/Kconfig" 153source "net/atm/Kconfig" 154source "net/bridge/Kconfig" 155source "net/8021q/Kconfig" 156source "net/decnet/Kconfig" 157source "net/llc/Kconfig" 158source "net/ipx/Kconfig" 159source "drivers/net/appletalk/Kconfig" 160source "net/x25/Kconfig" 161source "net/lapb/Kconfig" 162 163config NET_DIVERT 164 bool "Frame Diverter (EXPERIMENTAL)" 165 depends on EXPERIMENTAL 166 ---help--- 167 The Frame Diverter allows you to divert packets from the 168 network, that are not aimed at the interface receiving it (in 169 promisc. mode). Typically, a Linux box setup as an Ethernet bridge 170 with the Frames Diverter on, can do some *really* transparent www 171 caching using a Squid proxy for example. 172 173 This is very useful when you don't want to change your router's 174 config (or if you simply don't have access to it). 175 176 The other possible usages of diverting Ethernet Frames are 177 numberous: 178 - reroute smtp traffic to another interface 179 - traffic-shape certain network streams 180 - transparently proxy smtp connections 181 - etc... 182 183 For more informations, please refer to: 184 <http://diverter.sourceforge.net/> 185 <http://perso.wanadoo.fr/magpie/EtherDivert.html> 186 187 If unsure, say N. 188 189source "net/econet/Kconfig" 190source "net/wanrouter/Kconfig" 191source "net/sched/Kconfig" 192 193menu "Network testing" 194 195config NET_PKTGEN 196 tristate "Packet Generator (USE WITH CAUTION)" 197 depends on PROC_FS 198 ---help--- 199 This module will inject preconfigured packets, at a configurable 200 rate, out of a given interface. It is used for network interface 201 stress testing and performance analysis. If you don't understand 202 what was just said, you don't need it: say N. 203 204 Documentation on how to use the packet generator can be found 205 at <file:Documentation/networking/pktgen.txt>. 206 207 To compile this code as a module, choose M here: the 208 module will be called pktgen. 209 210endmenu 211 212endmenu 213 214source "net/ax25/Kconfig" 215source "net/irda/Kconfig" 216source "net/bluetooth/Kconfig" 217source "net/ieee80211/Kconfig" 218 219endif # if NET 220endmenu # Networking 221 222