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