2 # Network configuration
5 menu "Networking support"
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
13 other computer. If you are upgrading from an older kernel, you
14 should consider updating your networking tools too because changes
15 in the kernel and the tools often go hand in hand. The tools are
16 contained in the package net-tools, the location and version number
17 of which are given in <file:Documentation/Changes>.
19 For a general introduction to Linux networking, it is highly
20 recommended to read the NET-HOWTO, available from
21 <http://www.tldp.org/docs.html#howto>.
23 menu "Networking options"
27 tristate "Packet socket"
29 The Packet protocol is used by applications which communicate
30 directly with network devices without an intermediate network
31 protocol implemented in the kernel, e.g. tcpdump. If you want them
34 To compile this driver as a module, choose M here: the module will
40 bool "Packet socket: mmapped IO"
43 If you say Y here, the Packet protocol driver will use an IO
44 mechanism that results in faster communication.
49 tristate "Netlink device emulation"
51 This option will be removed soon. Any programs that want to use
52 character special nodes like /dev/tap0 or /dev/route (all with major
53 number 36) need this option, and need to be rewritten soon to use
54 the real netlink socket.
55 This is a backward compatibility option, choose Y for now.
58 tristate "Unix domain sockets"
60 If you say Y here, you will include support for Unix domain sockets;
61 sockets are the standard Unix mechanism for establishing and
62 accessing network connections. Many commonly used programs such as
63 the X Window system and syslog use these sockets even if your
64 machine is not connected to any network. Unless you are working on
65 an embedded system or something similar, you therefore definitely
68 To compile this driver as a module, choose M here: the module will be
69 called unix. Note that several important services won't work
70 correctly if you say M here and then neglect to load the module.
72 Say Y unless you know what you are doing.
75 tristate "PF_KEY sockets"
78 PF_KEYv2 socket family, compatible to KAME ones.
79 They are required if you are going to use IPsec tools ported
82 Say Y unless you know what you are doing.
85 bool "TCP/IP networking"
87 These are the protocols used on the Internet and on most local
88 Ethernets. It is highly recommended to say Y here (this will enlarge
89 your kernel by about 144 KB), since some programs (e.g. the X window
90 system) use TCP/IP even if your machine is not connected to any
91 other computer. You will get the so-called loopback device which
92 allows you to ping yourself (great fun, that!).
94 For an excellent introduction to Linux networking, please read the
95 Linux Networking HOWTO, available from
96 <http://www.tldp.org/docs.html#howto>.
98 If you say Y here and also to "/proc file system support" and
99 "Sysctl support" below, you can change various aspects of the
100 behavior of the TCP/IP code by writing to the (virtual) files in
101 /proc/sys/net/ipv4/*; the options are explained in the file
102 <file:Documentation/networking/ip-sysctl.txt>.
106 source "net/ipv4/Kconfig"
108 # IPv6 as module will cause a CRASH if you try to unload it
110 tristate "The IPv6 protocol (EXPERIMENTAL)"
111 depends on INET && EXPERIMENTAL
112 select CRYPTO if IPV6_PRIVACY
113 select CRYPTO_MD5 if IPV6_PRIVACY
115 This is experimental support for the IP version 6 (formerly called
116 IPng "IP next generation"). You will still be able to do
117 regular IPv4 networking as well.
119 Features of this new protocol include: expanded address space,
120 authentication and privacy, and seamless interoperability with the
121 current version of IP (IP version 4). For general information about
122 IPv6, see <http://playground.sun.com/pub/ipng/html/ipng-main.html>;
123 for specific information about IPv6 under Linux read the HOWTO at
124 <http://www.bieringer.de/linux/IPv6/> and the file net/ipv6/README
125 in the kernel source.
127 To compile this protocol support as a module, choose M here: the
128 module will be called ipv6.
130 It is safe to say N here for now.
132 source "net/ipv6/Kconfig"
135 bool "Network packet filtering (replaces ipchains)"
137 Netfilter is a framework for filtering and mangling network packets
138 that pass through your Linux box.
140 The most common use of packet filtering is to run your Linux box as
141 a firewall protecting a local network from the Internet. The type of
142 firewall provided by this kernel support is called a "packet
143 filter", which means that it can reject individual network packets
144 based on type, source, destination etc. The other kind of firewall,
145 a "proxy-based" one, is more secure but more intrusive and more
146 bothersome to set up; it inspects the network traffic much more
147 closely, modifies it and has knowledge about the higher level
148 protocols, which a packet filter lacks. Moreover, proxy-based
149 firewalls often require changes to the programs running on the local
150 clients. Proxy-based firewalls don't need support by the kernel, but
151 they are often combined with a packet filter, which only works if
154 You should also say Y here if you intend to use your Linux box as
155 the gateway to the Internet for a local network of machines without
156 globally valid IP addresses. This is called "masquerading": if one
157 of the computers on your local network wants to send something to
158 the outside, your box can "masquerade" as that computer, i.e. it
159 forwards the traffic to the intended outside destination, but
160 modifies the packets to make it look like they came from the
161 firewall box itself. It works both ways: if the outside host
162 replies, the Linux box will silently forward the traffic to the
163 correct local computer. This way, the computers on your local net
164 are completely invisible to the outside world, even though they can
165 reach the outside and can receive replies. It is even possible to
166 run globally visible servers from within a masqueraded local network
167 using a mechanism called portforwarding. Masquerading is also often
168 called NAT (Network Address Translation).
170 Another use of Netfilter is in transparent proxying: if a machine on
171 the local network tries to connect to an outside host, your Linux
172 box can transparently forward the traffic to a local server,
173 typically a caching proxy server.
175 Yet another use of Netfilter is building a bridging firewall. Using
176 a bridge with Network packet filtering enabled makes iptables "see"
177 the bridged traffic. For filtering on the lower network and Ethernet
178 protocols over the bridge, use ebtables (under bridge netfilter
181 Various modules exist for netfilter which replace the previous
182 masquerading (ipmasqadm), packet filtering (ipchains), transparent
183 proxying, and portforwarding mechanisms. Please see
184 <file:Documentation/Changes> under "iptables" for the location of
187 Make sure to say N to "Fast switching" below if you intend to say Y
188 here, as Fast switching currently bypasses netfilter.
190 Chances are that you should say Y here if you compile a kernel which
191 will run as a router and N for regular hosts. If unsure, say N.
195 config NETFILTER_DEBUG
196 bool "Network packet filtering debugging"
199 You can say Y here if you want to get additional messages useful in
200 debugging the netfilter code.
202 config BRIDGE_NETFILTER
203 bool "Bridged IP/ARP packets filtering"
204 depends on BRIDGE && NETFILTER && INET
207 Enabling this option will let arptables resp. iptables see bridged
208 ARP resp. IP traffic. If you want a bridging firewall, you probably
209 want this option enabled.
210 Enabling or disabling this option doesn't enable or disable
215 source "net/ipv4/netfilter/Kconfig"
216 source "net/ipv6/netfilter/Kconfig"
217 source "net/decnet/netfilter/Kconfig"
218 source "net/bridge/netfilter/Kconfig"
226 source "net/xfrm/Kconfig"
228 source "net/sctp/Kconfig"
231 tristate "Asynchronous Transfer Mode (ATM) (EXPERIMENTAL)"
232 depends on EXPERIMENTAL
234 ATM is a high-speed networking technology for Local Area Networks
235 and Wide Area Networks. It uses a fixed packet size and is
236 connection oriented, allowing for the negotiation of minimum
237 bandwidth requirements.
239 In order to participate in an ATM network, your Linux box needs an
240 ATM networking card. If you have that, say Y here and to the driver
241 of your ATM card below.
243 Note that you need a set of user-space programs to actually make use
244 of ATM. See the file <file:Documentation/networking/atm.txt> for
248 tristate "Classical IP over ATM (EXPERIMENTAL)"
249 depends on ATM && INET
251 Classical IP over ATM for PVCs and SVCs, supporting InARP and
252 ATMARP. If you want to communication with other IP hosts on your ATM
253 network, you will typically either say Y here or to "LAN Emulation
256 config ATM_CLIP_NO_ICMP
257 bool "Do NOT send ICMP if no neighbour (EXPERIMENTAL)"
260 Normally, an "ICMP host unreachable" message is sent if a neighbour
261 cannot be reached because there is no VC to it in the kernel's
262 ATMARP table. This may cause problems when ATMARP table entries are
263 briefly removed during revalidation. If you say Y here, packets to
264 such neighbours are silently discarded instead.
267 tristate "LAN Emulation (LANE) support (EXPERIMENTAL)"
270 LAN Emulation emulates services of existing LANs across an ATM
271 network. Besides operating as a normal ATM end station client, Linux
272 LANE client can also act as an proxy client bridging packets between
273 ELAN and Ethernet segments. You need LANE if you want to try MPOA.
276 tristate "Multi-Protocol Over ATM (MPOA) support (EXPERIMENTAL)"
277 depends on ATM && INET && ATM_LANE!=n
279 Multi-Protocol Over ATM allows ATM edge devices such as routers,
280 bridges and ATM attached hosts establish direct ATM VCs across
281 subnetwork boundaries. These shortcut connections bypass routers
282 enhancing overall network performance.
285 tristate "RFC1483/2684 Bridged protocols"
286 depends on ATM && INET
288 ATM PVCs can carry ethernet PDUs according to rfc2684 (formerly 1483)
289 This device will act like an ethernet from the kernels point of view,
290 with the traffic being carried by ATM PVCs (currently 1 PVC/device).
291 This is sometimes used over DSL lines. If in doubt, say N.
293 config ATM_BR2684_IPFILTER
294 bool "Per-VC IP filter kludge"
295 depends on ATM_BR2684
297 This is an experimental mechanism for users who need to terminating a
298 large number of IP-only vcc's. Do not enable this unless you are sure
299 you know what you are doing.
302 tristate "802.1d Ethernet Bridging"
304 If you say Y here, then your Linux box will be able to act as an
305 Ethernet bridge, which means that the different Ethernet segments it
306 is connected to will appear as one Ethernet to the participants.
307 Several such bridges can work together to create even larger
308 networks of Ethernets using the IEEE 802.1 spanning tree algorithm.
309 As this is a standard, Linux bridges will cooperate properly with
310 other third party bridge products.
312 In order to use the Ethernet bridge, you'll need the bridge
313 configuration tools; see <file:Documentation/networking/bridge.txt>
314 for location. Please read the Bridge mini-HOWTO for more
317 If you enable iptables support along with the bridge support then you
318 turn your bridge into a bridging IP firewall.
319 iptables will then see the IP packets being bridged, so you need to
320 take this into account when setting up your firewall rules.
321 Enabling arptables support when bridging will let arptables see
322 bridged ARP traffic in the arptables FORWARD chain.
324 To compile this code as a module, choose M here: the module
325 will be called bridge.
330 tristate "802.1Q VLAN Support"
332 Select this and you will be able to create 802.1Q VLAN interfaces
333 on your ethernet interfaces. 802.1Q VLAN supports almost
334 everything a regular ethernet interface does, including
335 firewalling, bridging, and of course IP traffic. You will need
336 the 'vconfig' tool from the VLAN project in order to effectively
337 use VLANs. See the VLAN web page for more information:
338 <http://www.candelatech.com/~greear/vlan.html>
340 To compile this code as a module, choose M here: the module
341 will be called 8021q.
346 tristate "DECnet Support"
348 The DECnet networking protocol was used in many products made by
349 Digital (now Compaq). It provides reliable stream and sequenced
350 packet communications over which run a variety of services similar
351 to those which run over TCP/IP.
353 To find some tools to use with the kernel layer support, please
354 look at Patrick Caulfield's web site:
355 <http://linux-decnet.sourceforge.net/>.
357 More detailed documentation is available in
358 <file:Documentation/networking/decnet.txt>.
360 Be sure to say Y to "/proc file system support" and "Sysctl support"
361 below when using DECnet, since you will need sysctl support to aid
362 in configuration at run time.
364 The DECnet code is also available as a module ( = code which can be
365 inserted in and removed from the running kernel whenever you want).
366 The module is called decnet.
368 source "net/decnet/Kconfig"
370 source "net/llc/Kconfig"
373 tristate "The IPX protocol"
376 This is support for the Novell networking protocol, IPX, commonly
377 used for local networks of Windows machines. You need it if you
378 want to access Novell NetWare file or print servers using the Linux
379 Novell client ncpfs (available from
380 <ftp://platan.vc.cvut.cz/pub/linux/ncpfs/>) or from
381 within the Linux DOS emulator DOSEMU (read the DOSEMU-HOWTO,
382 available from <http://www.tldp.org/docs.html#howto>). In order
383 to do the former, you'll also have to say Y to "NCP file system
386 IPX is similar in scope to IP, while SPX, which runs on top of IPX,
387 is similar to TCP. There is also experimental support for SPX in
388 Linux (see "SPX networking", below).
390 To turn your Linux box into a fully featured NetWare file server and
391 IPX router, say Y here and fetch either lwared from
392 <ftp://ibiblio.org/pub/Linux/system/network/daemons/> or
393 mars_nwe from <ftp://www.compu-art.de/mars_nwe/>. For more
394 information, read the IPX-HOWTO available from
395 <http://www.tldp.org/docs.html#howto>.
397 General information about how to connect Linux, Windows machines and
398 Macs is on the WWW at <http://www.eats.com/linux_mac_win.html>.
400 The IPX driver would enlarge your kernel by about 16 KB. To compile
401 this driver as a module, choose M here: the module will be called ipx.
402 Unless you want to integrate your Linux box with a local Novell
405 source "net/ipx/Kconfig"
408 tristate "Appletalk protocol support"
411 AppleTalk is the protocol that Apple computers can use to communicate
412 on a network. If your Linux box is connected to such a network and you
413 wish to connect to it, say Y. You will need to use the netatalk package
414 so that your Linux box can act as a print and file server for Macs as
415 well as access AppleTalk printers. Check out
416 <http://www.zettabyte.net/netatalk/> on the WWW for details.
417 EtherTalk is the name used for AppleTalk over Ethernet and the
418 cheaper and slower LocalTalk is AppleTalk over a proprietary Apple
419 network using serial links. EtherTalk and LocalTalk are fully
422 General information about how to connect Linux, Windows machines and
423 Macs is on the WWW at <http://www.eats.com/linux_mac_win.html>. The
424 NET-3-HOWTO, available from
425 <http://www.tldp.org/docs.html#howto>, contains valuable
428 To compile this driver as a module, choose M here: the module will be
429 called appletalk. You almost certainly want to compile it as a
430 module so you can restart your AppleTalk stack without rebooting
431 your machine. I hear that the GNU boycott of Apple is over, so
432 even politically correct people are allowed to say Y here.
434 source "drivers/net/appletalk/Kconfig"
437 tristate "CCITT X.25 Packet Layer (EXPERIMENTAL)"
438 depends on EXPERIMENTAL
440 X.25 is a set of standardized network protocols, similar in scope to
441 frame relay; the one physical line from your box to the X.25 network
442 entry point can carry several logical point-to-point connections
443 (called "virtual circuits") to other computers connected to the X.25
444 network. Governments, banks, and other organizations tend to use it
445 to connect to each other or to form Wide Area Networks (WANs). Many
446 countries have public X.25 networks. X.25 consists of two
447 protocols: the higher level Packet Layer Protocol (PLP) (say Y here
448 if you want that) and the lower level data link layer protocol LAPB
449 (say Y to "LAPB Data Link Driver" below if you want that).
451 You can read more about X.25 at <http://www.sangoma.com/x25.htm> and
452 <http://www.cisco.com/univercd/cc/td/doc/product/software/ios11/cbook/cx25.htm>.
453 Information about X.25 for Linux is contained in the files
454 <file:Documentation/networking/x25.txt> and
455 <file:Documentation/networking/x25-iface.txt>.
457 One connects to an X.25 network either with a dedicated network card
458 using the X.21 protocol (not yet supported by Linux) or one can do
459 X.25 over a standard telephone line using an ordinary modem (say Y
460 to "X.25 async driver" below) or over Ethernet using an ordinary
461 Ethernet card and the LAPB over Ethernet (say Y to "LAPB Data Link
462 Driver" and "LAPB over Ethernet driver" below).
464 To compile this driver as a module, choose M here: the module
465 will be called x25. If unsure, say N.
468 tristate "LAPB Data Link Driver (EXPERIMENTAL)"
469 depends on EXPERIMENTAL
471 Link Access Procedure, Balanced (LAPB) is the data link layer (i.e.
472 the lower) part of the X.25 protocol. It offers a reliable
473 connection service to exchange data frames with one other host, and
474 it is used to transport higher level protocols (mostly X.25 Packet
475 Layer, the higher part of X.25, but others are possible as well).
476 Usually, LAPB is used with specialized X.21 network cards, but Linux
477 currently supports LAPB only over Ethernet connections. If you want
478 to use LAPB connections over Ethernet, say Y here and to "LAPB over
479 Ethernet driver" below. Read
480 <file:Documentation/networking/lapb-module.txt> for technical
483 To compile this driver as a module, choose M here: the
484 module will be called lapb. If unsure, say N.
487 bool "Frame Diverter (EXPERIMENTAL)"
488 depends on EXPERIMENTAL
490 The Frame Diverter allows you to divert packets from the
491 network, that are not aimed at the interface receiving it (in
492 promisc. mode). Typically, a Linux box setup as an Ethernet bridge
493 with the Frames Diverter on, can do some *really* transparent www
494 caching using a Squid proxy for example.
496 This is very useful when you don't want to change your router's
497 config (or if you simply don't have access to it).
499 The other possible usages of diverting Ethernet Frames are
501 - reroute smtp traffic to another interface
502 - traffic-shape certain network streams
503 - transparently proxy smtp connections
506 For more informations, please refer to:
507 <http://diverter.sourceforge.net/>
508 <http://perso.wanadoo.fr/magpie/EtherDivert.html>
513 tristate "Acorn Econet/AUN protocols (EXPERIMENTAL)"
514 depends on EXPERIMENTAL && INET
516 Econet is a fairly old and slow networking protocol mainly used by
517 Acorn computers to access file and print servers. It uses native
518 Econet network cards. AUN is an implementation of the higher level
519 parts of Econet that runs over ordinary Ethernet connections, on
520 top of the UDP packet protocol, which in turn runs on top of the
521 Internet protocol IP.
523 If you say Y here, you can choose with the next two options whether
524 to send Econet/AUN traffic over a UDP Ethernet connection or over
525 a native Econet network card.
527 To compile this driver as a module, choose M here: the module
528 will be called econet.
534 Say Y here if you want to send Econet/AUN traffic over a UDP
535 connection (UDP is a packet based protocol that runs on top of the
536 Internet protocol IP) using an ordinary Ethernet network card.
542 Say Y here if you have a native Econet network card installed in
546 tristate "WAN router"
547 depends on EXPERIMENTAL
549 Wide Area Networks (WANs), such as X.25, frame relay and leased
550 lines, are used to interconnect Local Area Networks (LANs) over vast
551 distances with data transfer rates significantly higher than those
552 achievable with commonly used asynchronous modem connections.
553 Usually, a quite expensive external device called a `WAN router' is
554 needed to connect to a WAN.
556 As an alternative, WAN routing can be built into the Linux kernel.
557 With relatively inexpensive WAN interface cards available on the
558 market, a perfectly usable router can be built for less than half
559 the price of an external router. If you have one of those cards and
560 wish to use your Linux box as a WAN router, say Y here and also to
561 the WAN driver for your card, below. You will then need the
562 wan-tools package which is available from <ftp://ftp.sangoma.com/>.
563 Read <file:Documentation/networking/wan-router.txt> for more
566 To compile WAN routing support as a module, choose M here: the
567 module will be called wanrouter.
571 menu "QoS and/or fair queueing"
574 bool "QoS and/or fair queueing"
576 When the kernel has several packets to send out over a network
577 device, it has to decide which ones to send first, which ones to
578 delay, and which ones to drop. This is the job of the packet
579 scheduler, and several different algorithms for how to do this
580 "fairly" have been proposed.
582 If you say N here, you will get the standard packet scheduler, which
583 is a FIFO (first come, first served). If you say Y here, you will be
584 able to choose from among several alternative algorithms which can
585 then be attached to different network devices. This is useful for
586 example if some of your network devices are real time devices that
587 need a certain minimum data flow rate, or if you need to limit the
588 maximum data flow rate for traffic which matches specified criteria.
589 This code is considered to be experimental.
591 To administer these schedulers, you'll need the user-level utilities
592 from the package iproute2+tc at <ftp://ftp.tux.org/pub/net/ip-routing/>.
593 That package also contains some documentation; for more, check out
594 <http://snafu.freedom.org/linux2.2/iproute-notes.html>.
596 This Quality of Service (QoS) support will enable you to use
597 Differentiated Services (diffserv) and Resource Reservation Protocol
598 (RSVP) on your Linux router if you also say Y to "QoS support",
599 "Packet classifier API" and to some classifiers below. Documentation
600 and software is at <http://diffserv.sourceforge.net/>.
602 If you say Y here and to "/proc file system" below, you will be able
603 to read status information about packet schedulers from the file
606 The available schedulers are listed in the following questions; you
607 can say Y to as many as you like. If unsure, say N now.
609 source "net/sched/Kconfig"
613 menu "Network testing"
616 tristate "Packet Generator (USE WITH CAUTION)"
619 This module will inject preconfigured packets, at a configurable
620 rate, out of a given interface. It is used for network interface
621 stress testing and performance analysis. If you don't understand
622 what was just said, you don't need it: say N.
624 Documentation on how to use the packet generator can be found
625 at <file:Documentation/networking/pktgen.txt>.
627 To compile this code as a module, choose M here: the
628 module will be called pktgen.
638 bool "Netpoll support for trapping incoming packets"
643 bool "Netpoll traffic trapping"
647 config NET_POLL_CONTROLLER
650 source "net/ax25/Kconfig"
652 source "net/irda/Kconfig"
654 source "net/bluetooth/Kconfig"
656 source "drivers/net/Kconfig"