2 # Network configuration
8 bool "Networking support"
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
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>.
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>.
25 # Make sure that all config symbols are dependent on NET
28 menu "Networking options"
30 source "net/packet/Kconfig"
31 source "net/unix/Kconfig"
32 source "net/xfrm/Kconfig"
35 bool "TCP/IP networking"
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!).
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>.
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>.
57 source "net/ipv4/Kconfig"
58 source "net/ipv6/Kconfig"
63 bool "Network packet filtering (replaces ipchains)"
65 Netfilter is a framework for filtering and mangling network packets
66 that pass through your Linux box.
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
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).
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.
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
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
115 Make sure to say N to "Fast switching" below if you intend to say Y
116 here, as Fast switching currently bypasses netfilter.
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.
123 config NETFILTER_DEBUG
124 bool "Network packet filtering debugging"
127 You can say Y here if you want to get additional messages useful in
128 debugging the netfilter code.
130 config BRIDGE_NETFILTER
131 bool "Bridged IP/ARP packets filtering"
132 depends on BRIDGE && NETFILTER && INET
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
143 source "net/ipv4/netfilter/Kconfig"
144 source "net/ipv6/netfilter/Kconfig"
145 source "net/decnet/netfilter/Kconfig"
146 source "net/bridge/netfilter/Kconfig"
150 source "net/dccp/Kconfig"
151 source "net/sctp/Kconfig"
152 source "net/atm/Kconfig"
153 source "net/bridge/Kconfig"
154 source "net/8021q/Kconfig"
155 source "net/decnet/Kconfig"
156 source "net/llc/Kconfig"
157 source "net/ipx/Kconfig"
158 source "drivers/net/appletalk/Kconfig"
159 source "net/x25/Kconfig"
160 source "net/lapb/Kconfig"
163 bool "Frame Diverter (EXPERIMENTAL)"
164 depends on EXPERIMENTAL
166 The Frame Diverter allows you to divert packets from the
167 network, that are not aimed at the interface receiving it (in
168 promisc. mode). Typically, a Linux box setup as an Ethernet bridge
169 with the Frames Diverter on, can do some *really* transparent www
170 caching using a Squid proxy for example.
172 This is very useful when you don't want to change your router's
173 config (or if you simply don't have access to it).
175 The other possible usages of diverting Ethernet Frames are
177 - reroute smtp traffic to another interface
178 - traffic-shape certain network streams
179 - transparently proxy smtp connections
182 For more informations, please refer to:
183 <http://diverter.sourceforge.net/>
184 <http://perso.wanadoo.fr/magpie/EtherDivert.html>
188 source "net/econet/Kconfig"
189 source "net/wanrouter/Kconfig"
190 source "net/sched/Kconfig"
192 menu "Network testing"
195 tristate "Packet Generator (USE WITH CAUTION)"
198 This module will inject preconfigured packets, at a configurable
199 rate, out of a given interface. It is used for network interface
200 stress testing and performance analysis. If you don't understand
201 what was just said, you don't need it: say N.
203 Documentation on how to use the packet generator can be found
204 at <file:Documentation/networking/pktgen.txt>.
206 To compile this code as a module, choose M here: the
207 module will be called pktgen.
209 source "net/netfilter/Kconfig"
215 source "net/ax25/Kconfig"
216 source "net/irda/Kconfig"
217 source "net/bluetooth/Kconfig"
218 source "net/ieee80211/Kconfig"