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"
40 source "net/iucv/Kconfig"
43 bool "TCP/IP networking"
45 These are the protocols used on the Internet and on most local
46 Ethernets. It is highly recommended to say Y here (this will enlarge
47 your kernel by about 144 KB), since some programs (e.g. the X window
48 system) use TCP/IP even if your machine is not connected to any
49 other computer. You will get the so-called loopback device which
50 allows you to ping yourself (great fun, that!).
52 For an excellent introduction to Linux networking, please read the
53 Linux Networking HOWTO, available from
54 <http://www.tldp.org/docs.html#howto>.
56 If you say Y here and also to "/proc file system support" and
57 "Sysctl support" below, you can change various aspects of the
58 behavior of the TCP/IP code by writing to the (virtual) files in
59 /proc/sys/net/ipv4/*; the options are explained in the file
60 <file:Documentation/networking/ip-sysctl.txt>.
65 source "net/ipv4/Kconfig"
66 source "net/ipv6/Kconfig"
67 source "net/netlabel/Kconfig"
71 config NETWORK_SECMARK
72 bool "Security Marking"
74 This enables security marking of network packets, similar
75 to nfmark, but designated for security purposes.
76 If you are unsure how to answer this question, answer N.
79 bool "Network packet filtering framework (Netfilter)"
81 Netfilter is a framework for filtering and mangling network packets
82 that pass through your Linux box.
84 The most common use of packet filtering is to run your Linux box as
85 a firewall protecting a local network from the Internet. The type of
86 firewall provided by this kernel support is called a "packet
87 filter", which means that it can reject individual network packets
88 based on type, source, destination etc. The other kind of firewall,
89 a "proxy-based" one, is more secure but more intrusive and more
90 bothersome to set up; it inspects the network traffic much more
91 closely, modifies it and has knowledge about the higher level
92 protocols, which a packet filter lacks. Moreover, proxy-based
93 firewalls often require changes to the programs running on the local
94 clients. Proxy-based firewalls don't need support by the kernel, but
95 they are often combined with a packet filter, which only works if
98 You should also say Y here if you intend to use your Linux box as
99 the gateway to the Internet for a local network of machines without
100 globally valid IP addresses. This is called "masquerading": if one
101 of the computers on your local network wants to send something to
102 the outside, your box can "masquerade" as that computer, i.e. it
103 forwards the traffic to the intended outside destination, but
104 modifies the packets to make it look like they came from the
105 firewall box itself. It works both ways: if the outside host
106 replies, the Linux box will silently forward the traffic to the
107 correct local computer. This way, the computers on your local net
108 are completely invisible to the outside world, even though they can
109 reach the outside and can receive replies. It is even possible to
110 run globally visible servers from within a masqueraded local network
111 using a mechanism called portforwarding. Masquerading is also often
112 called NAT (Network Address Translation).
114 Another use of Netfilter is in transparent proxying: if a machine on
115 the local network tries to connect to an outside host, your Linux
116 box can transparently forward the traffic to a local server,
117 typically a caching proxy server.
119 Yet another use of Netfilter is building a bridging firewall. Using
120 a bridge with Network packet filtering enabled makes iptables "see"
121 the bridged traffic. For filtering on the lower network and Ethernet
122 protocols over the bridge, use ebtables (under bridge netfilter
125 Various modules exist for netfilter which replace the previous
126 masquerading (ipmasqadm), packet filtering (ipchains), transparent
127 proxying, and portforwarding mechanisms. Please see
128 <file:Documentation/Changes> under "iptables" for the location of
131 Make sure to say N to "Fast switching" below if you intend to say Y
132 here, as Fast switching currently bypasses netfilter.
134 Chances are that you should say Y here if you compile a kernel which
135 will run as a router and N for regular hosts. If unsure, say N.
139 config NETFILTER_DEBUG
140 bool "Network packet filtering debugging"
143 You can say Y here if you want to get additional messages useful in
144 debugging the netfilter code.
146 config BRIDGE_NETFILTER
147 bool "Bridged IP/ARP packets filtering"
148 depends on BRIDGE && NETFILTER && INET
151 Enabling this option will let arptables resp. iptables see bridged
152 ARP resp. IP traffic. If you want a bridging firewall, you probably
153 want this option enabled.
154 Enabling or disabling this option doesn't enable or disable
159 source "net/netfilter/Kconfig"
160 source "net/ipv4/netfilter/Kconfig"
161 source "net/ipv6/netfilter/Kconfig"
162 source "net/decnet/netfilter/Kconfig"
163 source "net/bridge/netfilter/Kconfig"
167 source "net/dccp/Kconfig"
168 source "net/sctp/Kconfig"
169 source "net/tipc/Kconfig"
170 source "net/atm/Kconfig"
171 source "net/bridge/Kconfig"
172 source "net/8021q/Kconfig"
173 source "net/decnet/Kconfig"
174 source "net/llc/Kconfig"
175 source "net/ipx/Kconfig"
176 source "drivers/net/appletalk/Kconfig"
177 source "net/x25/Kconfig"
178 source "net/lapb/Kconfig"
179 source "net/econet/Kconfig"
180 source "net/wanrouter/Kconfig"
181 source "net/sched/Kconfig"
183 menu "Network testing"
186 tristate "Packet Generator (USE WITH CAUTION)"
189 This module will inject preconfigured packets, at a configurable
190 rate, out of a given interface. It is used for network interface
191 stress testing and performance analysis. If you don't understand
192 what was just said, you don't need it: say N.
194 Documentation on how to use the packet generator can be found
195 at <file:Documentation/networking/pktgen.txt>.
197 To compile this code as a module, choose M here: the
198 module will be called pktgen.
201 tristate "TCP connection probing"
202 depends on INET && EXPERIMENTAL && PROC_FS && KPROBES
204 This module allows for capturing the changes to TCP connection
205 state in response to incoming packets. It is used for debugging
206 TCP congestion avoidance modules. If you don't understand
207 what was just said, you don't need it: say N.
209 Documentation on how to use TCP connection probing can be found
210 at http://linux-net.osdl.org/index.php/TcpProbe
212 To compile this code as a module, choose M here: the
213 module will be called tcp_probe.
219 source "net/ax25/Kconfig"
220 source "net/irda/Kconfig"
221 source "net/bluetooth/Kconfig"
222 source "net/ieee80211/Kconfig"