412 lines
16 KiB
Plaintext
412 lines
16 KiB
Plaintext
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#
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# IP configuration
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#
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config IP_MULTICAST
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bool "IP: multicasting"
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depends on INET
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help
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This is code for addressing several networked computers at once,
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enlarging your kernel by about 2 KB. You need multicasting if you
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intend to participate in the MBONE, a high bandwidth network on top
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of the Internet which carries audio and video broadcasts. More
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information about the MBONE is on the WWW at
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<http://www-itg.lbl.gov/mbone/>. Information about the multicast
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capabilities of the various network cards is contained in
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<file:Documentation/networking/multicast.txt>. For most people, it's
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safe to say N.
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config IP_ADVANCED_ROUTER
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bool "IP: advanced router"
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depends on INET
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---help---
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If you intend to run your Linux box mostly as a router, i.e. as a
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computer that forwards and redistributes network packets, say Y; you
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will then be presented with several options that allow more precise
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control about the routing process.
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The answer to this question won't directly affect the kernel:
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answering N will just cause the configurator to skip all the
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questions about advanced routing.
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Note that your box can only act as a router if you enable IP
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forwarding in your kernel; you can do that by saying Y to "/proc
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file system support" and "Sysctl support" below and executing the
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line
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echo "1" > /proc/sys/net/ipv4/ip_forward
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at boot time after the /proc file system has been mounted.
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If you turn on IP forwarding, you will also get the rp_filter, which
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automatically rejects incoming packets if the routing table entry
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for their source address doesn't match the network interface they're
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arriving on. This has security advantages because it prevents the
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so-called IP spoofing, however it can pose problems if you use
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asymmetric routing (packets from you to a host take a different path
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than packets from that host to you) or if you operate a non-routing
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host which has several IP addresses on different interfaces. To turn
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rp_filter off use:
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echo 0 > /proc/sys/net/ipv4/conf/<device>/rp_filter
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or
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echo 0 > /proc/sys/net/ipv4/conf/all/rp_filter
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If unsure, say N here.
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config IP_MULTIPLE_TABLES
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bool "IP: policy routing"
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depends on IP_ADVANCED_ROUTER
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---help---
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Normally, a router decides what to do with a received packet based
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solely on the packet's final destination address. If you say Y here,
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the Linux router will also be able to take the packet's source
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address into account. Furthermore, the TOS (Type-Of-Service) field
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of the packet can be used for routing decisions as well.
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If you are interested in this, please see the preliminary
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documentation at <http://www.compendium.com.ar/policy-routing.txt>
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and <ftp://post.tepkom.ru/pub/vol2/Linux/docs/advanced-routing.tex>.
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You will need supporting software from
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<ftp://ftp.tux.org/pub/net/ip-routing/>.
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If unsure, say N.
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config IP_ROUTE_FWMARK
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bool "IP: use netfilter MARK value as routing key"
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depends on IP_MULTIPLE_TABLES && NETFILTER
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help
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If you say Y here, you will be able to specify different routes for
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packets with different mark values (see iptables(8), MARK target).
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config IP_ROUTE_MULTIPATH
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bool "IP: equal cost multipath"
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depends on IP_ADVANCED_ROUTER
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help
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Normally, the routing tables specify a single action to be taken in
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a deterministic manner for a given packet. If you say Y here
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however, it becomes possible to attach several actions to a packet
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pattern, in effect specifying several alternative paths to travel
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for those packets. The router considers all these paths to be of
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equal "cost" and chooses one of them in a non-deterministic fashion
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if a matching packet arrives.
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config IP_ROUTE_MULTIPATH_CACHED
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bool "IP: equal cost multipath with caching support (EXPERIMENTAL)"
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depends on: IP_ROUTE_MULTIPATH
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help
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Normally, equal cost multipath routing is not supported by the
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routing cache. If you say Y here, alternative routes are cached
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and on cache lookup a route is chosen in a configurable fashion.
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If unsure, say N.
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config IP_ROUTE_MULTIPATH_RR
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tristate "MULTIPATH: round robin algorithm"
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depends on IP_ROUTE_MULTIPATH_CACHED
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help
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Mulitpath routes are chosen according to Round Robin
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config IP_ROUTE_MULTIPATH_RANDOM
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tristate "MULTIPATH: random algorithm"
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depends on IP_ROUTE_MULTIPATH_CACHED
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help
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Multipath routes are chosen in a random fashion. Actually,
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there is no weight for a route. The advantage of this policy
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is that it is implemented stateless and therefore introduces only
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a very small delay.
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config IP_ROUTE_MULTIPATH_WRANDOM
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tristate "MULTIPATH: weighted random algorithm"
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depends on IP_ROUTE_MULTIPATH_CACHED
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help
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Multipath routes are chosen in a weighted random fashion.
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The per route weights are the weights visible via ip route 2. As the
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corresponding state management introduces some overhead routing delay
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is increased.
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config IP_ROUTE_MULTIPATH_DRR
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tristate "MULTIPATH: interface round robin algorithm"
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depends on IP_ROUTE_MULTIPATH_CACHED
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help
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Connections are distributed in a round robin fashion over the
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available interfaces. This policy makes sense if the connections
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should be primarily distributed on interfaces and not on routes.
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config IP_ROUTE_VERBOSE
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bool "IP: verbose route monitoring"
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depends on IP_ADVANCED_ROUTER
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help
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If you say Y here, which is recommended, then the kernel will print
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verbose messages regarding the routing, for example warnings about
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received packets which look strange and could be evidence of an
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attack or a misconfigured system somewhere. The information is
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handled by the klogd daemon which is responsible for kernel messages
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("man klogd").
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config IP_PNP
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bool "IP: kernel level autoconfiguration"
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depends on INET
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help
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This enables automatic configuration of IP addresses of devices and
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of the routing table during kernel boot, based on either information
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supplied on the kernel command line or by BOOTP or RARP protocols.
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You need to say Y only for diskless machines requiring network
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access to boot (in which case you want to say Y to "Root file system
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on NFS" as well), because all other machines configure the network
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in their startup scripts.
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config IP_PNP_DHCP
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bool "IP: DHCP support"
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depends on IP_PNP
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---help---
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If you want your Linux box to mount its whole root file system (the
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one containing the directory /) from some other computer over the
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net via NFS and you want the IP address of your computer to be
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discovered automatically at boot time using the DHCP protocol (a
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special protocol designed for doing this job), say Y here. In case
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the boot ROM of your network card was designed for booting Linux and
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does DHCP itself, providing all necessary information on the kernel
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command line, you can say N here.
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If unsure, say Y. Note that if you want to use DHCP, a DHCP server
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must be operating on your network. Read
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<file:Documentation/nfsroot.txt> for details.
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config IP_PNP_BOOTP
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bool "IP: BOOTP support"
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depends on IP_PNP
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---help---
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If you want your Linux box to mount its whole root file system (the
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one containing the directory /) from some other computer over the
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net via NFS and you want the IP address of your computer to be
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discovered automatically at boot time using the BOOTP protocol (a
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special protocol designed for doing this job), say Y here. In case
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the boot ROM of your network card was designed for booting Linux and
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does BOOTP itself, providing all necessary information on the kernel
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command line, you can say N here. If unsure, say Y. Note that if you
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want to use BOOTP, a BOOTP server must be operating on your network.
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Read <file:Documentation/nfsroot.txt> for details.
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config IP_PNP_RARP
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bool "IP: RARP support"
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depends on IP_PNP
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help
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If you want your Linux box to mount its whole root file system (the
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one containing the directory /) from some other computer over the
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net via NFS and you want the IP address of your computer to be
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discovered automatically at boot time using the RARP protocol (an
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older protocol which is being obsoleted by BOOTP and DHCP), say Y
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here. Note that if you want to use RARP, a RARP server must be
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operating on your network. Read <file:Documentation/nfsroot.txt> for
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details.
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# not yet ready..
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# bool ' IP: ARP support' CONFIG_IP_PNP_ARP
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config NET_IPIP
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tristate "IP: tunneling"
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depends on INET
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select INET_TUNNEL
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---help---
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Tunneling means encapsulating data of one protocol type within
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another protocol and sending it over a channel that understands the
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encapsulating protocol. This particular tunneling driver implements
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encapsulation of IP within IP, which sounds kind of pointless, but
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can be useful if you want to make your (or some other) machine
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appear on a different network than it physically is, or to use
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mobile-IP facilities (allowing laptops to seamlessly move between
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networks without changing their IP addresses).
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Saying Y to this option will produce two modules ( = code which can
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be inserted in and removed from the running kernel whenever you
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want). Most people won't need this and can say N.
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config NET_IPGRE
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tristate "IP: GRE tunnels over IP"
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depends on INET
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select XFRM
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help
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Tunneling means encapsulating data of one protocol type within
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another protocol and sending it over a channel that understands the
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encapsulating protocol. This particular tunneling driver implements
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GRE (Generic Routing Encapsulation) and at this time allows
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encapsulating of IPv4 or IPv6 over existing IPv4 infrastructure.
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This driver is useful if the other endpoint is a Cisco router: Cisco
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likes GRE much better than the other Linux tunneling driver ("IP
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tunneling" above). In addition, GRE allows multicast redistribution
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through the tunnel.
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config NET_IPGRE_BROADCAST
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bool "IP: broadcast GRE over IP"
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depends on IP_MULTICAST && NET_IPGRE
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help
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One application of GRE/IP is to construct a broadcast WAN (Wide Area
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Network), which looks like a normal Ethernet LAN (Local Area
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Network), but can be distributed all over the Internet. If you want
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to do that, say Y here and to "IP multicast routing" below.
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config IP_MROUTE
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bool "IP: multicast routing"
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depends on IP_MULTICAST
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help
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This is used if you want your machine to act as a router for IP
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packets that have several destination addresses. It is needed on the
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MBONE, a high bandwidth network on top of the Internet which carries
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audio and video broadcasts. In order to do that, you would most
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likely run the program mrouted. Information about the multicast
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capabilities of the various network cards is contained in
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<file:Documentation/networking/multicast.txt>. If you haven't heard
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about it, you don't need it.
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config IP_PIMSM_V1
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bool "IP: PIM-SM version 1 support"
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depends on IP_MROUTE
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help
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Kernel side support for Sparse Mode PIM (Protocol Independent
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Multicast) version 1. This multicast routing protocol is used widely
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because Cisco supports it. You need special software to use it
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(pimd-v1). Please see <http://netweb.usc.edu/pim/> for more
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information about PIM.
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Say Y if you want to use PIM-SM v1. Note that you can say N here if
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you just want to use Dense Mode PIM.
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config IP_PIMSM_V2
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bool "IP: PIM-SM version 2 support"
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depends on IP_MROUTE
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help
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Kernel side support for Sparse Mode PIM version 2. In order to use
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this, you need an experimental routing daemon supporting it (pimd or
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gated-5). This routing protocol is not used widely, so say N unless
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you want to play with it.
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config ARPD
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bool "IP: ARP daemon support (EXPERIMENTAL)"
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depends on INET && EXPERIMENTAL
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---help---
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Normally, the kernel maintains an internal cache which maps IP
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addresses to hardware addresses on the local network, so that
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Ethernet/Token Ring/ etc. frames are sent to the proper address on
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the physical networking layer. For small networks having a few
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hundred directly connected hosts or less, keeping this address
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resolution (ARP) cache inside the kernel works well. However,
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maintaining an internal ARP cache does not work well for very large
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switched networks, and will use a lot of kernel memory if TCP/IP
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connections are made to many machines on the network.
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If you say Y here, the kernel's internal ARP cache will never grow
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to more than 256 entries (the oldest entries are expired in a LIFO
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manner) and communication will be attempted with the user space ARP
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daemon arpd. Arpd then answers the address resolution request either
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from its own cache or by asking the net.
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This code is experimental and also obsolete. If you want to use it,
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you need to find a version of the daemon arpd on the net somewhere,
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and you should also say Y to "Kernel/User network link driver",
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below. If unsure, say N.
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config SYN_COOKIES
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bool "IP: TCP syncookie support (disabled per default)"
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depends on INET
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---help---
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Normal TCP/IP networking is open to an attack known as "SYN
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flooding". This denial-of-service attack prevents legitimate remote
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users from being able to connect to your computer during an ongoing
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attack and requires very little work from the attacker, who can
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operate from anywhere on the Internet.
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SYN cookies provide protection against this type of attack. If you
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say Y here, the TCP/IP stack will use a cryptographic challenge
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protocol known as "SYN cookies" to enable legitimate users to
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continue to connect, even when your machine is under attack. There
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is no need for the legitimate users to change their TCP/IP software;
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SYN cookies work transparently to them. For technical information
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about SYN cookies, check out <http://cr.yp.to/syncookies.html>.
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If you are SYN flooded, the source address reported by the kernel is
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likely to have been forged by the attacker; it is only reported as
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an aid in tracing the packets to their actual source and should not
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be taken as absolute truth.
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SYN cookies may prevent correct error reporting on clients when the
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server is really overloaded. If this happens frequently better turn
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them off.
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If you say Y here, note that SYN cookies aren't enabled by default;
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you can enable them by saying Y to "/proc file system support" and
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"Sysctl support" below and executing the command
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echo 1 >/proc/sys/net/ipv4/tcp_syncookies
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at boot time after the /proc file system has been mounted.
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If unsure, say N.
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config INET_AH
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tristate "IP: AH transformation"
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depends on INET
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select XFRM
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select CRYPTO
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|
select CRYPTO_HMAC
|
||
|
|
select CRYPTO_MD5
|
||
|
|
select CRYPTO_SHA1
|
||
|
|
---help---
|
||
|
|
Support for IPsec AH.
|
||
|
|
|
||
|
|
If unsure, say Y.
|
||
|
|
|
||
|
|
config INET_ESP
|
||
|
|
tristate "IP: ESP transformation"
|
||
|
|
depends on INET
|
||
|
|
select XFRM
|
||
|
|
select CRYPTO
|
||
|
|
select CRYPTO_HMAC
|
||
|
|
select CRYPTO_MD5
|
||
|
|
select CRYPTO_SHA1
|
||
|
|
select CRYPTO_DES
|
||
|
|
---help---
|
||
|
|
Support for IPsec ESP.
|
||
|
|
|
||
|
|
If unsure, say Y.
|
||
|
|
|
||
|
|
config INET_IPCOMP
|
||
|
|
tristate "IP: IPComp transformation"
|
||
|
|
depends on INET
|
||
|
|
select XFRM
|
||
|
|
select INET_TUNNEL
|
||
|
|
select CRYPTO
|
||
|
|
select CRYPTO_DEFLATE
|
||
|
|
---help---
|
||
|
|
Support for IP Payload Compression Protocol (IPComp) (RFC3173),
|
||
|
|
typically needed for IPsec.
|
||
|
|
|
||
|
|
If unsure, say Y.
|
||
|
|
|
||
|
|
config INET_TUNNEL
|
||
|
|
tristate "IP: tunnel transformation"
|
||
|
|
depends on INET
|
||
|
|
select XFRM
|
||
|
|
---help---
|
||
|
|
Support for generic IP tunnel transformation, which is required by
|
||
|
|
the IP tunneling module as well as tunnel mode IPComp.
|
||
|
|
|
||
|
|
If unsure, say Y.
|
||
|
|
|
||
|
|
config IP_TCPDIAG
|
||
|
|
tristate "IP: TCP socket monitoring interface"
|
||
|
|
depends on INET
|
||
|
|
default y
|
||
|
|
---help---
|
||
|
|
Support for TCP socket monitoring interface used by native Linux
|
||
|
|
tools such as ss. ss is included in iproute2, currently downloadable
|
||
|
|
at <http://developer.osdl.org/dev/iproute2>. If you want IPv6 support
|
||
|
|
and have selected IPv6 as a module, you need to build this as a
|
||
|
|
module too.
|
||
|
|
|
||
|
|
If unsure, say Y.
|
||
|
|
|
||
|
|
config IP_TCPDIAG_IPV6
|
||
|
|
def_bool (IP_TCPDIAG=y && IPV6=y) || (IP_TCPDIAG=m && IPV6)
|
||
|
|
|
||
|
|
source "net/ipv4/ipvs/Kconfig"
|
||
|
|
|