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"
31 bool "Network packet debugging"
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
37 source "net/packet/Kconfig"
38 source "net/unix/Kconfig"
39 source "net/xfrm/Kconfig"
42 bool "TCP/IP networking"
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!).
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>.
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>.
64 source "net/ipv4/Kconfig"
65 source "net/ipv6/Kconfig"
69 config NETWORK_SECMARK
70 bool "Security Marking"
72 This enables security marking of network packets, similar
73 to nfmark, but designated for security purposes.
74 If you are unsure how to answer this question, answer N.
77 bool "Network packet filtering (replaces ipchains)"
79 Netfilter is a framework for filtering and mangling network packets
80 that pass through your Linux box.
82 The most common use of packet filtering is to run your Linux box as
83 a firewall protecting a local network from the Internet. The type of
84 firewall provided by this kernel support is called a "packet
85 filter", which means that it can reject individual network packets
86 based on type, source, destination etc. The other kind of firewall,
87 a "proxy-based" one, is more secure but more intrusive and more
88 bothersome to set up; it inspects the network traffic much more
89 closely, modifies it and has knowledge about the higher level
90 protocols, which a packet filter lacks. Moreover, proxy-based
91 firewalls often require changes to the programs running on the local
92 clients. Proxy-based firewalls don't need support by the kernel, but
93 they are often combined with a packet filter, which only works if
96 You should also say Y here if you intend to use your Linux box as
97 the gateway to the Internet for a local network of machines without
98 globally valid IP addresses. This is called "masquerading": if one
99 of the computers on your local network wants to send something to
100 the outside, your box can "masquerade" as that computer, i.e. it
101 forwards the traffic to the intended outside destination, but
102 modifies the packets to make it look like they came from the
103 firewall box itself. It works both ways: if the outside host
104 replies, the Linux box will silently forward the traffic to the
105 correct local computer. This way, the computers on your local net
106 are completely invisible to the outside world, even though they can
107 reach the outside and can receive replies. It is even possible to
108 run globally visible servers from within a masqueraded local network
109 using a mechanism called portforwarding. Masquerading is also often
110 called NAT (Network Address Translation).
112 Another use of Netfilter is in transparent proxying: if a machine on
113 the local network tries to connect to an outside host, your Linux
114 box can transparently forward the traffic to a local server,
115 typically a caching proxy server.
117 Yet another use of Netfilter is building a bridging firewall. Using
118 a bridge with Network packet filtering enabled makes iptables "see"
119 the bridged traffic. For filtering on the lower network and Ethernet
120 protocols over the bridge, use ebtables (under bridge netfilter
123 Various modules exist for netfilter which replace the previous
124 masquerading (ipmasqadm), packet filtering (ipchains), transparent
125 proxying, and portforwarding mechanisms. Please see
126 <file:Documentation/Changes> under "iptables" for the location of
129 Make sure to say N to "Fast switching" below if you intend to say Y
130 here, as Fast switching currently bypasses netfilter.
132 Chances are that you should say Y here if you compile a kernel which
133 will run as a router and N for regular hosts. If unsure, say N.
137 config NETFILTER_DEBUG
138 bool "Network packet filtering debugging"
141 You can say Y here if you want to get additional messages useful in
142 debugging the netfilter code.
144 config BRIDGE_NETFILTER
145 bool "Bridged IP/ARP packets filtering"
146 depends on BRIDGE && NETFILTER && INET
149 Enabling this option will let arptables resp. iptables see bridged
150 ARP resp. IP traffic. If you want a bridging firewall, you probably
151 want this option enabled.
152 Enabling or disabling this option doesn't enable or disable
157 source "net/netfilter/Kconfig"
158 source "net/ipv4/netfilter/Kconfig"
159 source "net/ipv6/netfilter/Kconfig"
160 source "net/decnet/netfilter/Kconfig"
161 source "net/bridge/netfilter/Kconfig"
165 source "net/dccp/Kconfig"
166 source "net/sctp/Kconfig"
167 source "net/tipc/Kconfig"
168 source "net/atm/Kconfig"
169 source "net/bridge/Kconfig"
170 source "net/8021q/Kconfig"
171 source "net/decnet/Kconfig"
172 source "net/llc/Kconfig"
173 source "net/ipx/Kconfig"
174 source "drivers/net/appletalk/Kconfig"
175 source "net/x25/Kconfig"
176 source "net/lapb/Kconfig"
179 bool "Frame Diverter (EXPERIMENTAL)"
180 depends on EXPERIMENTAL
182 The Frame Diverter allows you to divert packets from the
183 network, that are not aimed at the interface receiving it (in
184 promisc. mode). Typically, a Linux box setup as an Ethernet bridge
185 with the Frames Diverter on, can do some *really* transparent www
186 caching using a Squid proxy for example.
188 This is very useful when you don't want to change your router's
189 config (or if you simply don't have access to it).
191 The other possible usages of diverting Ethernet Frames are
193 - reroute smtp traffic to another interface
194 - traffic-shape certain network streams
195 - transparently proxy smtp connections
198 For more informations, please refer to:
199 <http://diverter.sourceforge.net/>
200 <http://perso.wanadoo.fr/magpie/EtherDivert.html>
204 source "net/econet/Kconfig"
205 source "net/wanrouter/Kconfig"
206 source "net/sched/Kconfig"
208 menu "Network testing"
211 tristate "Packet Generator (USE WITH CAUTION)"
214 This module will inject preconfigured packets, at a configurable
215 rate, out of a given interface. It is used for network interface
216 stress testing and performance analysis. If you don't understand
217 what was just said, you don't need it: say N.
219 Documentation on how to use the packet generator can be found
220 at <file:Documentation/networking/pktgen.txt>.
222 To compile this code as a module, choose M here: the
223 module will be called pktgen.
226 tristate "TCP connection probing"
227 depends on INET && EXPERIMENTAL && PROC_FS && KPROBES
229 This module allows for capturing the changes to TCP connection
230 state in response to incoming packets. It is used for debugging
231 TCP congestion avoidance modules. If you don't understand
232 what was just said, you don't need it: say N.
234 Documentation on how to use the packet generator can be found
235 at http://linux-net.osdl.org/index.php/TcpProbe
237 To compile this code as a module, choose M here: the
238 module will be called tcp_probe.
244 source "net/ax25/Kconfig"
245 source "net/irda/Kconfig"
246 source "net/bluetooth/Kconfig"
247 source "net/ieee80211/Kconfig"