root/net/Kconfig

#
# Network configuration
#

menu "Networking support"

config NET
        bool "Networking support"
        ---help---
          Unless you really know what you are doing, you should say Y here.
          The reason is that some programs need kernel networking support even
          when running on a stand-alone machine that isn't connected to any
          other computer. If you are upgrading from an older kernel, you
          should consider updating your networking tools too because changes
          in the kernel and the tools often go hand in hand. The tools are
          contained in the package net-tools, the location and version number
          of which are given in <file:Documentation/Changes>.

          For a general introduction to Linux networking, it is highly
          recommended to read the NET-HOWTO, available from
          <http://www.tldp.org/docs.html#howto>.

menu "Networking options"
        depends on NET

config PACKET
        tristate "Packet socket"
        ---help---
          The Packet protocol is used by applications which communicate
          directly with network devices without an intermediate network
          protocol implemented in the kernel, e.g. tcpdump.  If you want them
          to work, choose Y.

          To compile this driver as a module, choose M here: the module will
          be called af_packet.

          If unsure, say Y.

config PACKET_MMAP
        bool "Packet socket: mmapped IO"
        depends on PACKET
        help
          If you say Y here, the Packet protocol driver will use an IO
          mechanism that results in faster communication.

          If unsure, say N.

config NETLINK_DEV
        tristate "Netlink device emulation"
        help
          This option will be removed soon. Any programs that want to use
          character special nodes like /dev/tap0 or /dev/route (all with major
          number 36) need this option, and need to be rewritten soon to use
          the real netlink socket.
          This is a backward compatibility option, choose Y for now.

config UNIX
        tristate "Unix domain sockets"
        ---help---
          If you say Y here, you will include support for Unix domain sockets;
          sockets are the standard Unix mechanism for establishing and
          accessing network connections.  Many commonly used programs such as
          the X Window system and syslog use these sockets even if your
          machine is not connected to any network.  Unless you are working on
          an embedded system or something similar, you therefore definitely
          want to say Y here.

          To compile this driver as a module, choose M here: the module will be
          called unix.  Note that several important services won't work
          correctly if you say M here and then neglect to load the module.

          Say Y unless you know what you are doing.

config NET_KEY
        tristate "PF_KEY sockets"
        select XFRM
        ---help---
          PF_KEYv2 socket family, compatible to KAME ones.
          They are required if you are going to use IPsec tools ported
          from KAME.

          Say Y unless you know what you are doing.

config INET
        bool "TCP/IP networking"
        ---help---
          These are the protocols used on the Internet and on most local
          Ethernets. It is highly recommended to say Y here (this will enlarge
          your kernel by about 144 KB), since some programs (e.g. the X window
          system) use TCP/IP even if your machine is not connected to any
          other computer. You will get the so-called loopback device which
          allows you to ping yourself (great fun, that!).

          For an excellent introduction to Linux networking, please read the
          Linux Networking HOWTO, available from
          <http://www.tldp.org/docs.html#howto>.

          If you say Y here and also to "/proc file system support" and
          "Sysctl support" below, you can change various aspects of the
          behavior of the TCP/IP code by writing to the (virtual) files in
          /proc/sys/net/ipv4/*; the options are explained in the file
          <file:Documentation/networking/ip-sysctl.txt>.

          Short answer: say Y.

source "net/ipv4/Kconfig"

#   IPv6 as module will cause a CRASH if you try to unload it
config IPV6
        tristate "The IPv6 protocol (EXPERIMENTAL)"
        depends on INET && EXPERIMENTAL
        ---help---
          This is experimental support for the IP version 6 (formerly called
          IPng "IP next generation").  You will still be able to do
          regular IPv4 networking as well.

          Features of this new protocol include: expanded address space,
          authentication and privacy, and seamless interoperability with the
          current version of IP (IP version 4). For general information about
          IPv6, see <http://playground.sun.com/pub/ipng/html/ipng-main.html>;
          for specific information about IPv6 under Linux read the HOWTO at
          <http://www.bieringer.de/linux/IPv6/> and the file net/ipv6/README
          in the kernel source.

          To compile this protocol support as a module, choose M here: the 
          module will be called ipv6.

          It is safe to say N here for now.

source "net/ipv6/Kconfig"

menuconfig NETFILTER
        bool "Network packet filtering (replaces ipchains)"
        ---help---
          Netfilter is a framework for filtering and mangling network packets
          that pass through your Linux box.

          The most common use of packet filtering is to run your Linux box as
          a firewall protecting a local network from the Internet. The type of
          firewall provided by this kernel support is called a "packet
          filter", which means that it can reject individual network packets
          based on type, source, destination etc. The other kind of firewall,
          a "proxy-based" one, is more secure but more intrusive and more
          bothersome to set up; it inspects the network traffic much more
          closely, modifies it and has knowledge about the higher level
          protocols, which a packet filter lacks. Moreover, proxy-based
          firewalls often require changes to the programs running on the local
          clients. Proxy-based firewalls don't need support by the kernel, but
          they are often combined with a packet filter, which only works if
          you say Y here.

          You should also say Y here if you intend to use your Linux box as
          the gateway to the Internet for a local network of machines without
          globally valid IP addresses. This is called "masquerading": if one
          of the computers on your local network wants to send something to
          the outside, your box can "masquerade" as that computer, i.e. it
          forwards the traffic to the intended outside destination, but
          modifies the packets to make it look like they came from the
          firewall box itself. It works both ways: if the outside host
          replies, the Linux box will silently forward the traffic to the
          correct local computer. This way, the computers on your local net
          are completely invisible to the outside world, even though they can
          reach the outside and can receive replies. It is even possible to
          run globally visible servers from within a masqueraded local network
          using a mechanism called portforwarding. Masquerading is also often
          called NAT (Network Address Translation).

          Another use of Netfilter is in transparent proxying: if a machine on
          the local network tries to connect to an outside host, your Linux
          box can transparently forward the traffic to a local server,
          typically a caching proxy server.

          Yet another use of Netfilter is building a bridging firewall. Using
          a bridge with Network packet filtering enabled makes iptables "see"
          the bridged traffic. For filtering on the lower network and Ethernet
          protocols over the bridge, use ebtables (under bridge netfilter
          configuration).

          Various modules exist for netfilter which replace the previous
          masquerading (ipmasqadm), packet filtering (ipchains), transparent
          proxying, and portforwarding mechanisms. Please see
          <file:Documentation/Changes> under "iptables" for the location of
          these packages.

          Make sure to say N to "Fast switching" below if you intend to say Y
          here, as Fast switching currently bypasses netfilter.

          Chances are that you should say Y here if you compile a kernel which
          will run as a router and N for regular hosts. If unsure, say N.

if NETFILTER

config NETFILTER_DEBUG
        bool "Network packet filtering debugging"
        depends on NETFILTER
        help
          You can say Y here if you want to get additional messages useful in
          debugging the netfilter code.

config BRIDGE_NETFILTER
        bool "Bridged IP/ARP packets filtering"
        depends on BRIDGE && NETFILTER && INET
        default y
        ---help---
          Enabling this option will let arptables resp. iptables see bridged
          ARP resp. IP traffic. If you want a bridging firewall, you probably
          want this option enabled.
          Enabling or disabling this option doesn't enable or disable
          ebtables.

          If unsure, say N.

source "net/ipv4/netfilter/Kconfig"
source "net/ipv6/netfilter/Kconfig"
source "net/decnet/netfilter/Kconfig"
source "net/bridge/netfilter/Kconfig"

endif

source "net/xfrm/Kconfig"

source "net/sctp/Kconfig"

config ATM
        tristate "Asynchronous Transfer Mode (ATM) (EXPERIMENTAL)"
        depends on EXPERIMENTAL
        ---help---
          ATM is a high-speed networking technology for Local Area Networks
          and Wide Area Networks.  It uses a fixed packet size and is
          connection oriented, allowing for the negotiation of minimum
          bandwidth requirements.

          In order to participate in an ATM network, your Linux box needs an
          ATM networking card. If you have that, say Y here and to the driver
          of your ATM card below.

          Note that you need a set of user-space programs to actually make use
          of ATM.  See the file <file:Documentation/networking/atm.txt> for
          further details.

config ATM_CLIP
        tristate "Classical IP over ATM (EXPERIMENTAL)"
        depends on ATM && INET
        help
          Classical IP over ATM for PVCs and SVCs, supporting InARP and
          ATMARP. If you want to communication with other IP hosts on your ATM
          network, you will typically either say Y here or to "LAN Emulation
          (LANE)" below.

config ATM_CLIP_NO_ICMP
        bool "Do NOT send ICMP if no neighbour (EXPERIMENTAL)"
        depends on ATM_CLIP
        help
          Normally, an "ICMP host unreachable" message is sent if a neighbour
          cannot be reached because there is no VC to it in the kernel's
          ATMARP table. This may cause problems when ATMARP table entries are
          briefly removed during revalidation. If you say Y here, packets to
          such neighbours are silently discarded instead.

config ATM_LANE
        tristate "LAN Emulation (LANE) support (EXPERIMENTAL)"
        depends on ATM
        help
          LAN Emulation emulates services of existing LANs across an ATM
          network. Besides operating as a normal ATM end station client, Linux
          LANE client can also act as an proxy client bridging packets between
          ELAN and Ethernet segments. You need LANE if you want to try MPOA.

config ATM_MPOA
        tristate "Multi-Protocol Over ATM (MPOA) support (EXPERIMENTAL)"
        depends on ATM && INET && ATM_LANE!=n
        help
          Multi-Protocol Over ATM allows ATM edge devices such as routers,
          bridges and ATM attached hosts establish direct ATM VCs across
          subnetwork boundaries. These shortcut connections bypass routers
          enhancing overall network performance.

config ATM_BR2684
        tristate "RFC1483/2684 Bridged protocols"
        depends on ATM && INET
        help
          ATM PVCs can carry ethernet PDUs according to rfc2684 (formerly 1483)
          This device will act like an ethernet from the kernels point of view,
          with the traffic being carried by ATM PVCs (currently 1 PVC/device).
          This is sometimes used over DSL lines.  If in doubt, say N.

config ATM_BR2684_IPFILTER
        bool "Per-VC IP filter kludge"
        depends on ATM_BR2684
        help
          This is an experimental mechanism for users who need to terminating a
          large number of IP-only vcc's.  Do not enable this unless you are sure
          you know what you are doing.

config BRIDGE
        tristate "802.1d Ethernet Bridging"
        ---help---
          If you say Y here, then your Linux box will be able to act as an
          Ethernet bridge, which means that the different Ethernet segments it
          is connected to will appear as one Ethernet to the participants.
          Several such bridges can work together to create even larger
          networks of Ethernets using the IEEE 802.1 spanning tree algorithm.
          As this is a standard, Linux bridges will cooperate properly with
          other third party bridge products.

          In order to use the Ethernet bridge, you'll need the bridge
          configuration tools; see <file:Documentation/networking/bridge.txt>
          for location. Please read the Bridge mini-HOWTO for more
          information.

          If you enable iptables support along with the bridge support then you
          turn your bridge into a bridging IP firewall.
          iptables will then see the IP packets being bridged, so you need to
          take this into account when setting up your firewall rules.
          Enabling arptables support when bridging will let arptables see
          bridged ARP traffic in the arptables FORWARD chain.

          To compile this code as a module, choose M here: the module
          will be called bridge.

          If unsure, say N.

config VLAN_8021Q
        tristate "802.1Q VLAN Support"

config DECNET
        tristate "DECnet Support"
        ---help---
          The DECnet networking protocol was used in many products made by
          Digital (now Compaq).  It provides reliable stream and sequenced
          packet communications over which run a variety of services similar
          to those which run over TCP/IP.

          To find some tools to use with the kernel layer support, please
          look at Patrick Caulfield's web site:
          <http://linux-decnet.sourceforge.net/>.

          More detailed documentation is available in
          <file:Documentation/networking/decnet.txt>.

          Be sure to say Y to "/proc file system support" and "Sysctl support"
          below when using DECnet, since you will need sysctl support to aid
          in configuration at run time.

          The DECnet code is also available as a module ( = code which can be
          inserted in and removed from the running kernel whenever you want).
          The module is called decnet.

source "net/decnet/Kconfig"

source "net/llc/Kconfig"

config IPX
        tristate "The IPX protocol"
        select LLC
        ---help---
          This is support for the Novell networking protocol, IPX, commonly
          used for local networks of Windows machines.  You need it if you
          want to access Novell NetWare file or print servers using the Linux
          Novell client ncpfs (available from
          <ftp://platan.vc.cvut.cz/pub/linux/ncpfs/>) or from
          within the Linux DOS emulator DOSEMU (read the DOSEMU-HOWTO,
          available from <http://www.tldp.org/docs.html#howto>).  In order
          to do the former, you'll also have to say Y to "NCP file system
          support", below.

          IPX is similar in scope to IP, while SPX, which runs on top of IPX,
          is similar to TCP. There is also experimental support for SPX in
          Linux (see "SPX networking", below).

          To turn your Linux box into a fully featured NetWare file server and
          IPX router, say Y here and fetch either lwared from
          <ftp://ibiblio.org/pub/Linux/system/network/daemons/> or
          mars_nwe from <ftp://www.compu-art.de/mars_nwe/>. For more
          information, read the IPX-HOWTO available from
          <http://www.tldp.org/docs.html#howto>.

          General information about how to connect Linux, Windows machines and
          Macs is on the WWW at <http://www.eats.com/linux_mac_win.html>.

          The IPX driver would enlarge your kernel by about 16 KB. To compile
          this driver as a module, choose M here: the module will be called ipx.
          Unless you want to integrate your Linux box with a local Novell
          network, say N.

source "net/ipx/Kconfig"

config ATALK
        tristate "Appletalk protocol support"
        select LLC
        ---help---
          AppleTalk is the protocol that Apple computers can use to communicate
          on a network.  If your Linux box is connected to such a network and you
          wish to connect to it, say Y.  You will need to use the netatalk package
          so that your Linux box can act as a print and file server for Macs as
          well as access AppleTalk printers.  Check out
          <http://www.zettabyte.net/netatalk/> on the WWW for details.
          EtherTalk is the name used for AppleTalk over Ethernet and the
          cheaper and slower LocalTalk is AppleTalk over a proprietary Apple
          network using serial links.  EtherTalk and LocalTalk are fully
          supported by Linux.

          General information about how to connect Linux, Windows machines and
          Macs is on the WWW at <http://www.eats.com/linux_mac_win.html>.  The
          NET-3-HOWTO, available from
          <http://www.tldp.org/docs.html#howto>, contains valuable
          information as well.

          To compile this driver as a module, choose M here: the module will be
          called appletalk. You almost certainly want to compile it as a
          module so you can restart your AppleTalk stack without rebooting
          your machine. I hear that the GNU boycott of Apple is over, so
          even politically correct people are allowed to say Y here.

source "drivers/net/appletalk/Kconfig"

config X25
        tristate "CCITT X.25 Packet Layer (EXPERIMENTAL)"
        depends on EXPERIMENTAL
        ---help---
          X.25 is a set of standardized network protocols, similar in scope to
          frame relay; the one physical line from your box to the X.25 network
          entry point can carry several logical point-to-point connections
          (called "virtual circuits") to other computers connected to the X.25
          network. Governments, banks, and other organizations tend to use it
          to connect to each other or to form Wide Area Networks (WANs). Many
          countries have public X.25 networks. X.25 consists of two
          protocols: the higher level Packet Layer Protocol (PLP) (say Y here
          if you want that) and the lower level data link layer protocol LAPB
          (say Y to "LAPB Data Link Driver" below if you want that).

          You can read more about X.25 at <http://www.sangoma.com/x25.htm> and
          <http://www.cisco.com/univercd/cc/td/doc/product/software/ios11/cbook/cx25.htm>.
          Information about X.25 for Linux is contained in the files
          <file:Documentation/networking/x25.txt> and
          <file:Documentation/networking/x25-iface.txt>.

          One connects to an X.25 network either with a dedicated network card
          using the X.21 protocol (not yet supported by Linux) or one can do
          X.25 over a standard telephone line using an ordinary modem (say Y
          to "X.25 async driver" below) or over Ethernet using an ordinary
          Ethernet card and the LAPB over Ethernet (say Y to "LAPB Data Link
          Driver" and "LAPB over Ethernet driver" below).

          To compile this driver as a module, choose M here: the module
          will be called x25. If unsure, say N.

config LAPB
        tristate "LAPB Data Link Driver (EXPERIMENTAL)"
        depends on EXPERIMENTAL
        ---help---
          Link Access Procedure, Balanced (LAPB) is the data link layer (i.e.
          the lower) part of the X.25 protocol. It offers a reliable
          connection service to exchange data frames with one other host, and
          it is used to transport higher level protocols (mostly X.25 Packet
          Layer, the higher part of X.25, but others are possible as well).
          Usually, LAPB is used with specialized X.21 network cards, but Linux
          currently supports LAPB only over Ethernet connections. If you want
          to use LAPB connections over Ethernet, say Y here and to "LAPB over
          Ethernet driver" below. Read
          <file:Documentation/networking/lapb-module.txt> for technical
          details.

          To compile this driver as a module, choose M here: the
          module will be called lapb.  If unsure, say N.

config NET_DIVERT
        bool "Frame Diverter (EXPERIMENTAL)"
        depends on EXPERIMENTAL
        ---help---
          The Frame Diverter allows you to divert packets from the
          network, that are not aimed at the interface receiving it (in
          promisc. mode). Typically, a Linux box setup as an Ethernet bridge
          with the Frames Diverter on, can do some *really* transparent www
          caching using a Squid proxy for example.

          This is very useful when you don't want to change your router's
          config (or if you simply don't have access to it).

          The other possible usages of diverting Ethernet Frames are
          numberous:
          - reroute smtp traffic to another interface
          - traffic-shape certain network streams
          - transparently proxy smtp connections
          - etc...

          For more informations, please refer to:
          <http://diverter.sourceforge.net/>
          <http://perso.wanadoo.fr/magpie/EtherDivert.html>

          If unsure, say N.

config ECONET
        tristate "Acorn Econet/AUN protocols (EXPERIMENTAL)"
        depends on EXPERIMENTAL && INET
        ---help---
          Econet is a fairly old and slow networking protocol mainly used by
          Acorn computers to access file and print servers. It uses native
          Econet network cards. AUN is an implementation of the higher level
          parts of Econet that runs over ordinary Ethernet connections, on
          top of the UDP packet protocol, which in turn runs on top of the
          Internet protocol IP.

          If you say Y here, you can choose with the next two options whether
          to send Econet/AUN traffic over a UDP Ethernet connection or over
          a native Econet network card.

          To compile this driver as a module, choose M here: the module
          will be called econet.

config ECONET_AUNUDP
        bool "AUN over UDP"
        depends on ECONET
        help
          Say Y here if you want to send Econet/AUN traffic over a UDP
          connection (UDP is a packet based protocol that runs on top of the
          Internet protocol IP) using an ordinary Ethernet network card.

config ECONET_NATIVE
        bool "Native Econet"
        depends on ECONET
        help
          Say Y here if you have a native Econet network card installed in
          your computer.

config WAN_ROUTER
        tristate "WAN router"
        depends on EXPERIMENTAL
        ---help---
          Wide Area Networks (WANs), such as X.25, frame relay and leased
          lines, are used to interconnect Local Area Networks (LANs) over vast
          distances with data transfer rates significantly higher than those
          achievable with commonly used asynchronous modem connections.
          Usually, a quite expensive external device called a `WAN router' is
          needed to connect to a WAN.

          As an alternative, WAN routing can be built into the Linux kernel.
          With relatively inexpensive WAN interface cards available on the
          market, a perfectly usable router can be built for less than half
          the price of an external router.  If you have one of those cards and
          wish to use your Linux box as a WAN router, say Y here and also to
          the WAN driver for your card, below.  You will then need the
          wan-tools package which is available from <ftp://ftp.sangoma.com/>.
          Read <file:Documentation/networking/wan-router.txt> for more
          information.

          To compile WAN routing support as a module, choose M here: the
          module will be called wanrouter.

          If unsure, say N.

config NET_FASTROUTE
        bool "Fast switching (read help!)"
        depends on EXPERIMENTAL
        ---help---
          Saying Y here enables direct NIC-to-NIC (NIC = Network Interface
          Card) data transfers on the local network, which is fast.

          IMPORTANT NOTE: This option is NOT COMPATIBLE with "Network packet
          filtering" (CONFIG_NETFILTER). Say N here if you say Y there.

          However, it will work with all options in the "Advanced router"
          section (except for "Use TOS value as routing key" and
          "Use FWMARK value as routing key").

          At the moment, few devices support fast switching (tulip is one of
          them, a modified 8390 driver can be found at
          <ftp://ftp.tux.org/pub/net/ip-routing/fastroute/fastroute-8390.tar.gz>).

          If unsure, say N.

config NET_HW_FLOWCONTROL
        bool "Forwarding between high speed interfaces"
        depends on EXPERIMENTAL
        ---help---
          This option enables NIC (Network Interface Card) hardware throttling
          during periods of extreme congestion. At the moment only a couple
          of device drivers support it (really only one -- tulip, a modified
          8390 driver can be found at
          <ftp://ftp.tux.org/pub/net/ip-routing/fastroute/fastroute-8390.tar.gz>).

          Really, this option is applicable to any machine attached to a fast
          enough network, and even a 10 Mb NIC is able to kill a not very slow
          box, such as a 120MHz Pentium.

          However, do not say Y here if you did not experience any serious
          problems.


menu "QoS and/or fair queueing"

config NET_SCHED
        bool "QoS and/or fair queueing"
        ---help---
          When the kernel has several packets to send out over a network
          device, it has to decide which ones to send first, which ones to
          delay, and which ones to drop. This is the job of the packet
          scheduler, and several different algorithms for how to do this
          "fairly" have been proposed.

          If you say N here, you will get the standard packet scheduler, which
          is a FIFO (first come, first served). If you say Y here, you will be
          able to choose from among several alternative algorithms which can
          then be attached to different network devices. This is useful for
          example if some of your network devices are real time devices that
          need a certain minimum data flow rate, or if you need to limit the
          maximum data flow rate for traffic which matches specified criteria.
          This code is considered to be experimental.

          To administer these schedulers, you'll need the user-level utilities
          from the package iproute2+tc at <ftp://ftp.tux.org/pub/net/ip-routing/>.
          That package also contains some documentation; for more, check out
          <http://snafu.freedom.org/linux2.2/iproute-notes.html>.

          This Quality of Service (QoS) support will enable you to use
          Differentiated Services (diffserv) and Resource Reservation Protocol
          (RSVP) on your Linux router if you also say Y to "QoS support",
          "Packet classifier API" and to some classifiers below. Documentation
          and software is at <http://diffserv.sourceforge.net/>.

          If you say Y here and to "/proc file system" below, you will be able
          to read status information about packet schedulers from the file
          /proc/net/psched.

          The available schedulers are listed in the following questions; you
          can say Y to as many as you like. If unsure, say N now.

source "net/sched/Kconfig"

endmenu

menu "Network testing"

config NET_PKTGEN
        tristate "Packet Generator (USE WITH CAUTION)"
        depends on PROC_FS
        ---help---
          This module will inject preconfigured packets, at a configurable
          rate, out of a given interface.  It is used for network interface
          stress testing and performance analysis.  If you don't understand
          what was just said, you don't need it: say N.

          Documentation on how to use the packet generaor can be found
          at <file:Documentation/networking/pktgen.txt>.

          To compile this code as a module, choose M here: the
          module will be called pktgen.

endmenu

endmenu

config NETPOLL
        def_bool NETCONSOLE

config NETPOLL_RX
        bool "Netpoll support for trapping incoming packets"
        default n
        depends on NETPOLL

config NETPOLL_TRAP
        bool "Netpoll traffic trapping"
        default n
        depends on NETPOLL

config NET_POLL_CONTROLLER
        def_bool NETPOLL

source "net/ax25/Kconfig"

source "net/irda/Kconfig"

source "net/bluetooth/Kconfig"

source "drivers/net/Kconfig"

endmenu