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"
66 source "net/netlabel/Kconfig"
70 config NETWORK_SECMARK
71 bool "Security Marking"
73 This enables security marking of network packets, similar
74 to nfmark, but designated for security purposes.
75 If you are unsure how to answer this question, answer N.
78 bool "Network packet filtering framework (Netfilter)"
80 Netfilter is a framework for filtering and mangling network packets
81 that pass through your Linux box.
83 The most common use of packet filtering is to run your Linux box as
84 a firewall protecting a local network from the Internet. The type of
85 firewall provided by this kernel support is called a "packet
86 filter", which means that it can reject individual network packets
87 based on type, source, destination etc. The other kind of firewall,
88 a "proxy-based" one, is more secure but more intrusive and more
89 bothersome to set up; it inspects the network traffic much more
90 closely, modifies it and has knowledge about the higher level
91 protocols, which a packet filter lacks. Moreover, proxy-based
92 firewalls often require changes to the programs running on the local
93 clients. Proxy-based firewalls don't need support by the kernel, but
94 they are often combined with a packet filter, which only works if
97 You should also say Y here if you intend to use your Linux box as
98 the gateway to the Internet for a local network of machines without
99 globally valid IP addresses. This is called "masquerading": if one
100 of the computers on your local network wants to send something to
101 the outside, your box can "masquerade" as that computer, i.e. it
102 forwards the traffic to the intended outside destination, but
103 modifies the packets to make it look like they came from the
104 firewall box itself. It works both ways: if the outside host
105 replies, the Linux box will silently forward the traffic to the
106 correct local computer. This way, the computers on your local net
107 are completely invisible to the outside world, even though they can
108 reach the outside and can receive replies. It is even possible to
109 run globally visible servers from within a masqueraded local network
110 using a mechanism called portforwarding. Masquerading is also often
111 called NAT (Network Address Translation).
113 Another use of Netfilter is in transparent proxying: if a machine on
114 the local network tries to connect to an outside host, your Linux
115 box can transparently forward the traffic to a local server,
116 typically a caching proxy server.
118 Yet another use of Netfilter is building a bridging firewall. Using
119 a bridge with Network packet filtering enabled makes iptables "see"
120 the bridged traffic. For filtering on the lower network and Ethernet
121 protocols over the bridge, use ebtables (under bridge netfilter
124 Various modules exist for netfilter which replace the previous
125 masquerading (ipmasqadm), packet filtering (ipchains), transparent
126 proxying, and portforwarding mechanisms. Please see
127 <file:Documentation/Changes> under "iptables" for the location of
130 Make sure to say N to "Fast switching" below if you intend to say Y
131 here, as Fast switching currently bypasses netfilter.
133 Chances are that you should say Y here if you compile a kernel which
134 will run as a router and N for regular hosts. If unsure, say N.
138 config NETFILTER_DEBUG
139 bool "Network packet filtering debugging"
142 You can say Y here if you want to get additional messages useful in
143 debugging the netfilter code.
145 config BRIDGE_NETFILTER
146 bool "Bridged IP/ARP packets filtering"
147 depends on BRIDGE && NETFILTER && INET
150 Enabling this option will let arptables resp. iptables see bridged
151 ARP resp. IP traffic. If you want a bridging firewall, you probably
152 want this option enabled.
153 Enabling or disabling this option doesn't enable or disable
158 source "net/netfilter/Kconfig"
159 source "net/ipv4/netfilter/Kconfig"
160 source "net/ipv6/netfilter/Kconfig"
161 source "net/decnet/netfilter/Kconfig"
162 source "net/bridge/netfilter/Kconfig"
166 source "net/dccp/Kconfig"
167 source "net/sctp/Kconfig"
168 source "net/tipc/Kconfig"
169 source "net/atm/Kconfig"
170 source "net/bridge/Kconfig"
171 source "net/8021q/Kconfig"
172 source "net/decnet/Kconfig"
173 source "net/llc/Kconfig"
174 source "net/ipx/Kconfig"
175 source "drivers/net/appletalk/Kconfig"
176 source "net/x25/Kconfig"
177 source "net/lapb/Kconfig"
178 source "net/econet/Kconfig"
179 source "net/wanrouter/Kconfig"
180 source "net/sched/Kconfig"
182 menu "Network testing"
185 tristate "Packet Generator (USE WITH CAUTION)"
188 This module will inject preconfigured packets, at a configurable
189 rate, out of a given interface. It is used for network interface
190 stress testing and performance analysis. If you don't understand
191 what was just said, you don't need it: say N.
193 Documentation on how to use the packet generator can be found
194 at <file:Documentation/networking/pktgen.txt>.
196 To compile this code as a module, choose M here: the
197 module will be called pktgen.
200 tristate "TCP connection probing"
201 depends on INET && EXPERIMENTAL && PROC_FS && KPROBES
203 This module allows for capturing the changes to TCP connection
204 state in response to incoming packets. It is used for debugging
205 TCP congestion avoidance modules. If you don't understand
206 what was just said, you don't need it: say N.
208 Documentation on how to use TCP connection probing can be found
209 at http://linux-net.osdl.org/index.php/TcpProbe
211 To compile this code as a module, choose M here: the
212 module will be called tcp_probe.
218 source "net/ax25/Kconfig"
219 source "net/irda/Kconfig"
220 source "net/bluetooth/Kconfig"
221 source "net/ieee80211/Kconfig"