## Network configuration# menu "Networking" 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>. # Make sure that all config symbols are dependent on NETif NET menu "Networking options" config NETDEBUG	bool "Network packet debugging"	help	  You can say Y here if you want to get additional messages useful in	  debugging bad packets, but can overwhelm logs under denial of service	  attacks. source "net/packet/Kconfig"source "net/unix/Kconfig"source "net/xfrm/Kconfig" 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. if INETsource "net/ipv4/Kconfig"source "net/ipv6/Kconfig" endif # if INET config NETWORK_SECMARK	bool "Security Marking"	help	  This enables security marking of network packets, similar	  to nfmark, but designated for security purposes.	  If you are unsure how to answer this question, answer N. 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/netfilter/Kconfig"source "net/ipv4/netfilter/Kconfig"source "net/ipv6/netfilter/Kconfig"source "net/decnet/netfilter/Kconfig"source "net/bridge/netfilter/Kconfig" endif source "net/dccp/Kconfig"source "net/sctp/Kconfig"source "net/tipc/Kconfig"source "net/atm/Kconfig"source "net/bridge/Kconfig"source "net/8021q/Kconfig"source "net/decnet/Kconfig"source "net/llc/Kconfig"source "net/ipx/Kconfig"source "drivers/net/appletalk/Kconfig"source "net/x25/Kconfig"source "net/lapb/Kconfig" 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. source "net/econet/Kconfig"source "net/wanrouter/Kconfig"source "net/sched/Kconfig" 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 generator 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. config NET_TCPPROBE	tristate "TCP connection probing"	depends on INET && EXPERIMENTAL && PROC_FS && KPROBES	---help---	This module allows for capturing the changes to TCP connection	state in response to incoming packets. It is used for debugging	TCP congestion avoidance modules. If you don't understand	what was just said, you don't need it: say N. 	Documentation on how to use the packet generator can be found	at http://linux-net.osdl.org/index.php/TcpProbe 	To compile this code as a module, choose M here: the	module will be called tcp_probe. endmenu endmenu source "net/ax25/Kconfig"source "net/irda/Kconfig"source "net/bluetooth/Kconfig"source "net/ieee80211/Kconfig" config WIRELESS_EXT	bool endif   # if NETendmenu # Networking