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 30config NETDEBUG 31 bool "Network packet debugging" 32 help 33 You can say Y here if you want to get additional messages useful in 34 debugging bad packets, but can overwhelm logs under denial of service 35 attacks. 36 37source "net/packet/Kconfig" 38source "net/unix/Kconfig" 39source "net/xfrm/Kconfig" 40 41config INET 42 bool "TCP/IP networking" 43 ---help--- 44 These are the protocols used on the Internet and on most local 45 Ethernets. It is highly recommended to say Y here (this will enlarge 46 your kernel by about 144 KB), since some programs (e.g. the X window 47 system) use TCP/IP even if your machine is not connected to any 48 other computer. You will get the so-called loopback device which 49 allows you to ping yourself (great fun, that!). 50 51 For an excellent introduction to Linux networking, please read the 52 Linux Networking HOWTO, available from 53 <http://www.tldp.org/docs.html#howto>. 54 55 If you say Y here and also to "/proc file system support" and 56 "Sysctl support" below, you can change various aspects of the 57 behavior of the TCP/IP code by writing to the (virtual) files in 58 /proc/sys/net/ipv4/*; the options are explained in the file 59 <file:Documentation/networking/ip-sysctl.txt>. 60 61 Short answer: say Y. 62 63if INET 64source "net/ipv4/Kconfig" 65source "net/ipv6/Kconfig" 66 67endif # if INET 68 69menuconfig NETFILTER 70 bool "Network packet filtering (replaces ipchains)" 71 ---help--- 72 Netfilter is a framework for filtering and mangling network packets 73 that pass through your Linux box. 74 75 The most common use of packet filtering is to run your Linux box as 76 a firewall protecting a local network from the Internet. The type of 77 firewall provided by this kernel support is called a "packet 78 filter", which means that it can reject individual network packets 79 based on type, source, destination etc. The other kind of firewall, 80 a "proxy-based" one, is more secure but more intrusive and more 81 bothersome to set up; it inspects the network traffic much more 82 closely, modifies it and has knowledge about the higher level 83 protocols, which a packet filter lacks. Moreover, proxy-based 84 firewalls often require changes to the programs running on the local 85 clients. Proxy-based firewalls don't need support by the kernel, but 86 they are often combined with a packet filter, which only works if 87 you say Y here. 88 89 You should also say Y here if you intend to use your Linux box as 90 the gateway to the Internet for a local network of machines without 91 globally valid IP addresses. This is called "masquerading": if one 92 of the computers on your local network wants to send something to 93 the outside, your box can "masquerade" as that computer, i.e. it 94 forwards the traffic to the intended outside destination, but 95 modifies the packets to make it look like they came from the 96 firewall box itself. It works both ways: if the outside host 97 replies, the Linux box will silently forward the traffic to the 98 correct local computer. This way, the computers on your local net 99 are completely invisible to the outside world, even though they can 100 reach the outside and can receive replies. It is even possible to 101 run globally visible servers from within a masqueraded local network 102 using a mechanism called portforwarding. Masquerading is also often 103 called NAT (Network Address Translation). 104 105 Another use of Netfilter is in transparent proxying: if a machine on 106 the local network tries to connect to an outside host, your Linux 107 box can transparently forward the traffic to a local server, 108 typically a caching proxy server. 109 110 Yet another use of Netfilter is building a bridging firewall. Using 111 a bridge with Network packet filtering enabled makes iptables "see" 112 the bridged traffic. For filtering on the lower network and Ethernet 113 protocols over the bridge, use ebtables (under bridge netfilter 114 configuration). 115 116 Various modules exist for netfilter which replace the previous 117 masquerading (ipmasqadm), packet filtering (ipchains), transparent 118 proxying, and portforwarding mechanisms. Please see 119 <file:Documentation/Changes> under "iptables" for the location of 120 these packages. 121 122 Make sure to say N to "Fast switching" below if you intend to say Y 123 here, as Fast switching currently bypasses netfilter. 124 125 Chances are that you should say Y here if you compile a kernel which 126 will run as a router and N for regular hosts. If unsure, say N. 127 128if NETFILTER 129 130config NETFILTER_DEBUG 131 bool "Network packet filtering debugging" 132 depends on NETFILTER 133 help 134 You can say Y here if you want to get additional messages useful in 135 debugging the netfilter code. 136 137config BRIDGE_NETFILTER 138 bool "Bridged IP/ARP packets filtering" 139 depends on BRIDGE && NETFILTER && INET 140 default y 141 ---help--- 142 Enabling this option will let arptables resp. iptables see bridged 143 ARP resp. IP traffic. If you want a bridging firewall, you probably 144 want this option enabled. 145 Enabling or disabling this option doesn't enable or disable 146 ebtables. 147 148 If unsure, say N. 149 150source "net/netfilter/Kconfig" 151source "net/ipv4/netfilter/Kconfig" 152source "net/ipv6/netfilter/Kconfig" 153source "net/decnet/netfilter/Kconfig" 154source "net/bridge/netfilter/Kconfig" 155 156endif 157 158source "net/dccp/Kconfig" 159source "net/sctp/Kconfig" 160source "net/tipc/Kconfig" 161source "net/atm/Kconfig" 162source "net/bridge/Kconfig" 163source "net/8021q/Kconfig" 164source "net/decnet/Kconfig" 165source "net/llc/Kconfig" 166source "net/ipx/Kconfig" 167source "drivers/net/appletalk/Kconfig" 168source "net/x25/Kconfig" 169source "net/lapb/Kconfig" 170 171config NET_DIVERT 172 bool "Frame Diverter (EXPERIMENTAL)" 173 depends on EXPERIMENTAL 174 ---help--- 175 The Frame Diverter allows you to divert packets from the 176 network, that are not aimed at the interface receiving it (in 177 promisc. mode). Typically, a Linux box setup as an Ethernet bridge 178 with the Frames Diverter on, can do some *really* transparent www 179 caching using a Squid proxy for example. 180 181 This is very useful when you don't want to change your router's 182 config (or if you simply don't have access to it). 183 184 The other possible usages of diverting Ethernet Frames are 185 numberous: 186 - reroute smtp traffic to another interface 187 - traffic-shape certain network streams 188 - transparently proxy smtp connections 189 - etc... 190 191 For more informations, please refer to: 192 <http://diverter.sourceforge.net/> 193 <http://perso.wanadoo.fr/magpie/EtherDivert.html> 194 195 If unsure, say N. 196 197source "net/econet/Kconfig" 198source "net/wanrouter/Kconfig" 199source "net/sched/Kconfig" 200 201menu "Network testing" 202 203config NET_PKTGEN 204 tristate "Packet Generator (USE WITH CAUTION)" 205 depends on PROC_FS 206 ---help--- 207 This module will inject preconfigured packets, at a configurable 208 rate, out of a given interface. It is used for network interface 209 stress testing and performance analysis. If you don't understand 210 what was just said, you don't need it: say N. 211 212 Documentation on how to use the packet generator can be found 213 at <file:Documentation/networking/pktgen.txt>. 214 215 To compile this code as a module, choose M here: the 216 module will be called pktgen. 217 218endmenu 219 220endmenu 221 222source "net/ax25/Kconfig" 223source "net/irda/Kconfig" 224source "net/bluetooth/Kconfig" 225source "net/ieee80211/Kconfig" 226 227config WIRELESS_EXT 228 bool 229 230endif # if NET 231endmenu # Networking 232 233