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"
222 source "net/xfrm/Kconfig"
224 source "net/sctp/Kconfig"
227 tristate "Asynchronous Transfer Mode (ATM) (EXPERIMENTAL)"
228 depends on EXPERIMENTAL
230 ATM is a high-speed networking technology for Local Area Networks
231 and Wide Area Networks. It uses a fixed packet size and is
232 connection oriented, allowing for the negotiation of minimum
233 bandwidth requirements.
235 In order to participate in an ATM network, your Linux box needs an
236 ATM networking card. If you have that, say Y here and to the driver
237 of your ATM card below.
239 Note that you need a set of user-space programs to actually make use
240 of ATM. See the file <file:Documentation/networking/atm.txt> for
244 tristate "Classical IP over ATM (EXPERIMENTAL)"
245 depends on ATM && INET
247 Classical IP over ATM for PVCs and SVCs, supporting InARP and
248 ATMARP. If you want to communication with other IP hosts on your ATM
249 network, you will typically either say Y here or to "LAN Emulation
252 config ATM_CLIP_NO_ICMP
253 bool "Do NOT send ICMP if no neighbour (EXPERIMENTAL)"
256 Normally, an "ICMP host unreachable" message is sent if a neighbour
257 cannot be reached because there is no VC to it in the kernel's
258 ATMARP table. This may cause problems when ATMARP table entries are
259 briefly removed during revalidation. If you say Y here, packets to
260 such neighbours are silently discarded instead.
263 tristate "LAN Emulation (LANE) support (EXPERIMENTAL)"
266 LAN Emulation emulates services of existing LANs across an ATM
267 network. Besides operating as a normal ATM end station client, Linux
268 LANE client can also act as an proxy client bridging packets between
269 ELAN and Ethernet segments. You need LANE if you want to try MPOA.
272 tristate "Multi-Protocol Over ATM (MPOA) support (EXPERIMENTAL)"
273 depends on ATM && INET && ATM_LANE!=n
275 Multi-Protocol Over ATM allows ATM edge devices such as routers,
276 bridges and ATM attached hosts establish direct ATM VCs across
277 subnetwork boundaries. These shortcut connections bypass routers
278 enhancing overall network performance.
281 tristate "RFC1483/2684 Bridged protocols"
282 depends on ATM && INET
284 ATM PVCs can carry ethernet PDUs according to rfc2684 (formerly 1483)
285 This device will act like an ethernet from the kernels point of view,
286 with the traffic being carried by ATM PVCs (currently 1 PVC/device).
287 This is sometimes used over DSL lines. If in doubt, say N.
289 config ATM_BR2684_IPFILTER
290 bool "Per-VC IP filter kludge"
291 depends on ATM_BR2684
293 This is an experimental mechanism for users who need to terminating a
294 large number of IP-only vcc's. Do not enable this unless you are sure
295 you know what you are doing.
298 tristate "802.1d Ethernet Bridging"
300 If you say Y here, then your Linux box will be able to act as an
301 Ethernet bridge, which means that the different Ethernet segments it
302 is connected to will appear as one Ethernet to the participants.
303 Several such bridges can work together to create even larger
304 networks of Ethernets using the IEEE 802.1 spanning tree algorithm.
305 As this is a standard, Linux bridges will cooperate properly with
306 other third party bridge products.
308 In order to use the Ethernet bridge, you'll need the bridge
309 configuration tools; see <file:Documentation/networking/bridge.txt>
310 for location. Please read the Bridge mini-HOWTO for more
313 If you enable iptables support along with the bridge support then you
314 turn your bridge into a bridging IP firewall.
315 iptables will then see the IP packets being bridged, so you need to
316 take this into account when setting up your firewall rules.
317 Enabling arptables support when bridging will let arptables see
318 bridged ARP traffic in the arptables FORWARD chain.
320 To compile this code as a module, choose M here: the module
321 will be called bridge.
326 tristate "802.1Q VLAN Support"
328 Select this and you will be able to create 802.1Q VLAN interfaces
329 on your ethernet interfaces. 802.1Q VLAN supports almost
330 everything a regular ethernet interface does, including
331 firewalling, bridging, and of course IP traffic. You will need
332 the 'vconfig' tool from the VLAN project in order to effectively
333 use VLANs. See the VLAN web page for more information:
334 <http://www.candelatech.com/~greear/vlan.html>
336 To compile this code as a module, choose M here: the module
337 will be called 8021q.
342 tristate "DECnet Support"
344 The DECnet networking protocol was used in many products made by
345 Digital (now Compaq). It provides reliable stream and sequenced
346 packet communications over which run a variety of services similar
347 to those which run over TCP/IP.
349 To find some tools to use with the kernel layer support, please
350 look at Patrick Caulfield's web site:
351 <http://linux-decnet.sourceforge.net/>.
353 More detailed documentation is available in
354 <file:Documentation/networking/decnet.txt>.
356 Be sure to say Y to "/proc file system support" and "Sysctl support"
357 below when using DECnet, since you will need sysctl support to aid
358 in configuration at run time.
360 The DECnet code is also available as a module ( = code which can be
361 inserted in and removed from the running kernel whenever you want).
362 The module is called decnet.
364 source "net/decnet/Kconfig"
366 source "net/llc/Kconfig"
369 tristate "The IPX protocol"
372 This is support for the Novell networking protocol, IPX, commonly
373 used for local networks of Windows machines. You need it if you
374 want to access Novell NetWare file or print servers using the Linux
375 Novell client ncpfs (available from
376 <ftp://platan.vc.cvut.cz/pub/linux/ncpfs/>) or from
377 within the Linux DOS emulator DOSEMU (read the DOSEMU-HOWTO,
378 available from <http://www.tldp.org/docs.html#howto>). In order
379 to do the former, you'll also have to say Y to "NCP file system
382 IPX is similar in scope to IP, while SPX, which runs on top of IPX,
383 is similar to TCP. There is also experimental support for SPX in
384 Linux (see "SPX networking", below).
386 To turn your Linux box into a fully featured NetWare file server and
387 IPX router, say Y here and fetch either lwared from
388 <ftp://ibiblio.org/pub/Linux/system/network/daemons/> or
389 mars_nwe from <ftp://www.compu-art.de/mars_nwe/>. For more
390 information, read the IPX-HOWTO available from
391 <http://www.tldp.org/docs.html#howto>.
393 General information about how to connect Linux, Windows machines and
394 Macs is on the WWW at <http://www.eats.com/linux_mac_win.html>.
396 The IPX driver would enlarge your kernel by about 16 KB. To compile
397 this driver as a module, choose M here: the module will be called ipx.
398 Unless you want to integrate your Linux box with a local Novell
401 source "net/ipx/Kconfig"
404 tristate "Appletalk protocol support"
407 AppleTalk is the protocol that Apple computers can use to communicate
408 on a network. If your Linux box is connected to such a network and you
409 wish to connect to it, say Y. You will need to use the netatalk package
410 so that your Linux box can act as a print and file server for Macs as
411 well as access AppleTalk printers. Check out
412 <http://www.zettabyte.net/netatalk/> on the WWW for details.
413 EtherTalk is the name used for AppleTalk over Ethernet and the
414 cheaper and slower LocalTalk is AppleTalk over a proprietary Apple
415 network using serial links. EtherTalk and LocalTalk are fully
418 General information about how to connect Linux, Windows machines and
419 Macs is on the WWW at <http://www.eats.com/linux_mac_win.html>. The
420 NET-3-HOWTO, available from
421 <http://www.tldp.org/docs.html#howto>, contains valuable
424 To compile this driver as a module, choose M here: the module will be
425 called appletalk. You almost certainly want to compile it as a
426 module so you can restart your AppleTalk stack without rebooting
427 your machine. I hear that the GNU boycott of Apple is over, so
428 even politically correct people are allowed to say Y here.
430 source "drivers/net/appletalk/Kconfig"
433 tristate "CCITT X.25 Packet Layer (EXPERIMENTAL)"
434 depends on EXPERIMENTAL
436 X.25 is a set of standardized network protocols, similar in scope to
437 frame relay; the one physical line from your box to the X.25 network
438 entry point can carry several logical point-to-point connections
439 (called "virtual circuits") to other computers connected to the X.25
440 network. Governments, banks, and other organizations tend to use it
441 to connect to each other or to form Wide Area Networks (WANs). Many
442 countries have public X.25 networks. X.25 consists of two
443 protocols: the higher level Packet Layer Protocol (PLP) (say Y here
444 if you want that) and the lower level data link layer protocol LAPB
445 (say Y to "LAPB Data Link Driver" below if you want that).
447 You can read more about X.25 at <http://www.sangoma.com/x25.htm> and
448 <http://www.cisco.com/univercd/cc/td/doc/product/software/ios11/cbook/cx25.htm>.
449 Information about X.25 for Linux is contained in the files
450 <file:Documentation/networking/x25.txt> and
451 <file:Documentation/networking/x25-iface.txt>.
453 One connects to an X.25 network either with a dedicated network card
454 using the X.21 protocol (not yet supported by Linux) or one can do
455 X.25 over a standard telephone line using an ordinary modem (say Y
456 to "X.25 async driver" below) or over Ethernet using an ordinary
457 Ethernet card and the LAPB over Ethernet (say Y to "LAPB Data Link
458 Driver" and "LAPB over Ethernet driver" below).
460 To compile this driver as a module, choose M here: the module
461 will be called x25. If unsure, say N.
464 tristate "LAPB Data Link Driver (EXPERIMENTAL)"
465 depends on EXPERIMENTAL
467 Link Access Procedure, Balanced (LAPB) is the data link layer (i.e.
468 the lower) part of the X.25 protocol. It offers a reliable
469 connection service to exchange data frames with one other host, and
470 it is used to transport higher level protocols (mostly X.25 Packet
471 Layer, the higher part of X.25, but others are possible as well).
472 Usually, LAPB is used with specialized X.21 network cards, but Linux
473 currently supports LAPB only over Ethernet connections. If you want
474 to use LAPB connections over Ethernet, say Y here and to "LAPB over
475 Ethernet driver" below. Read
476 <file:Documentation/networking/lapb-module.txt> for technical
479 To compile this driver as a module, choose M here: the
480 module will be called lapb. If unsure, say N.
483 bool "Frame Diverter (EXPERIMENTAL)"
484 depends on EXPERIMENTAL
486 The Frame Diverter allows you to divert packets from the
487 network, that are not aimed at the interface receiving it (in
488 promisc. mode). Typically, a Linux box setup as an Ethernet bridge
489 with the Frames Diverter on, can do some *really* transparent www
490 caching using a Squid proxy for example.
492 This is very useful when you don't want to change your router's
493 config (or if you simply don't have access to it).
495 The other possible usages of diverting Ethernet Frames are
497 - reroute smtp traffic to another interface
498 - traffic-shape certain network streams
499 - transparently proxy smtp connections
502 For more informations, please refer to:
503 <http://diverter.sourceforge.net/>
504 <http://perso.wanadoo.fr/magpie/EtherDivert.html>
509 tristate "Acorn Econet/AUN protocols (EXPERIMENTAL)"
510 depends on EXPERIMENTAL && INET
512 Econet is a fairly old and slow networking protocol mainly used by
513 Acorn computers to access file and print servers. It uses native
514 Econet network cards. AUN is an implementation of the higher level
515 parts of Econet that runs over ordinary Ethernet connections, on
516 top of the UDP packet protocol, which in turn runs on top of the
517 Internet protocol IP.
519 If you say Y here, you can choose with the next two options whether
520 to send Econet/AUN traffic over a UDP Ethernet connection or over
521 a native Econet network card.
523 To compile this driver as a module, choose M here: the module
524 will be called econet.
530 Say Y here if you want to send Econet/AUN traffic over a UDP
531 connection (UDP is a packet based protocol that runs on top of the
532 Internet protocol IP) using an ordinary Ethernet network card.
538 Say Y here if you have a native Econet network card installed in
542 tristate "WAN router"
543 depends on EXPERIMENTAL
545 Wide Area Networks (WANs), such as X.25, frame relay and leased
546 lines, are used to interconnect Local Area Networks (LANs) over vast
547 distances with data transfer rates significantly higher than those
548 achievable with commonly used asynchronous modem connections.
549 Usually, a quite expensive external device called a `WAN router' is
550 needed to connect to a WAN.
552 As an alternative, WAN routing can be built into the Linux kernel.
553 With relatively inexpensive WAN interface cards available on the
554 market, a perfectly usable router can be built for less than half
555 the price of an external router. If you have one of those cards and
556 wish to use your Linux box as a WAN router, say Y here and also to
557 the WAN driver for your card, below. You will then need the
558 wan-tools package which is available from <ftp://ftp.sangoma.com/>.
559 Read <file:Documentation/networking/wan-router.txt> for more
562 To compile WAN routing support as a module, choose M here: the
563 module will be called wanrouter.
567 config NET_HW_FLOWCONTROL
568 bool "Forwarding between high speed interfaces"
569 depends on EXPERIMENTAL
571 This option enables NIC (Network Interface Card) hardware throttling
572 during periods of extreme congestion. At the moment only a couple
573 of device drivers support it (really only one -- tulip, a modified
574 8390 driver can be found at
575 <ftp://ftp.tux.org/pub/net/ip-routing/fastroute/fastroute-8390.tar.gz>).
577 Really, this option is applicable to any machine attached to a fast
578 enough network, and even a 10 Mb NIC is able to kill a not very slow
579 box, such as a 120MHz Pentium.
581 However, do not say Y here if you did not experience any serious
585 menu "QoS and/or fair queueing"
588 bool "QoS and/or fair queueing"
590 When the kernel has several packets to send out over a network
591 device, it has to decide which ones to send first, which ones to
592 delay, and which ones to drop. This is the job of the packet
593 scheduler, and several different algorithms for how to do this
594 "fairly" have been proposed.
596 If you say N here, you will get the standard packet scheduler, which
597 is a FIFO (first come, first served). If you say Y here, you will be
598 able to choose from among several alternative algorithms which can
599 then be attached to different network devices. This is useful for
600 example if some of your network devices are real time devices that
601 need a certain minimum data flow rate, or if you need to limit the
602 maximum data flow rate for traffic which matches specified criteria.
603 This code is considered to be experimental.
605 To administer these schedulers, you'll need the user-level utilities
606 from the package iproute2+tc at <ftp://ftp.tux.org/pub/net/ip-routing/>.
607 That package also contains some documentation; for more, check out
608 <http://snafu.freedom.org/linux2.2/iproute-notes.html>.
610 This Quality of Service (QoS) support will enable you to use
611 Differentiated Services (diffserv) and Resource Reservation Protocol
612 (RSVP) on your Linux router if you also say Y to "QoS support",
613 "Packet classifier API" and to some classifiers below. Documentation
614 and software is at <http://diffserv.sourceforge.net/>.
616 If you say Y here and to "/proc file system" below, you will be able
617 to read status information about packet schedulers from the file
620 The available schedulers are listed in the following questions; you
621 can say Y to as many as you like. If unsure, say N now.
623 source "net/sched/Kconfig"
627 menu "Network testing"
630 tristate "Packet Generator (USE WITH CAUTION)"
633 This module will inject preconfigured packets, at a configurable
634 rate, out of a given interface. It is used for network interface
635 stress testing and performance analysis. If you don't understand
636 what was just said, you don't need it: say N.
638 Documentation on how to use the packet generaor can be found
639 at <file:Documentation/networking/pktgen.txt>.
641 To compile this code as a module, choose M here: the
642 module will be called pktgen.
652 bool "Netpoll support for trapping incoming packets"
657 bool "Netpoll traffic trapping"
661 config NET_POLL_CONTROLLER
664 source "net/ax25/Kconfig"
666 source "net/irda/Kconfig"
668 source "net/bluetooth/Kconfig"
670 source "drivers/net/Kconfig"