Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
new file mode 100644
index 0000000..a2c893a7
--- /dev/null
+++ b/Documentation/networking/ip-sysctl.txt
@@ -0,0 +1,878 @@
+/proc/sys/net/ipv4/* Variables:
+
+ip_forward - BOOLEAN
+ 0 - disabled (default)
+ not 0 - enabled
+
+ Forward Packets between interfaces.
+
+ This variable is special, its change resets all configuration
+ parameters to their default state (RFC1122 for hosts, RFC1812
+ for routers)
+
+ip_default_ttl - INTEGER
+ default 64
+
+ip_no_pmtu_disc - BOOLEAN
+ Disable Path MTU Discovery.
+ default FALSE
+
+min_pmtu - INTEGER
+ default 562 - minimum discovered Path MTU
+
+mtu_expires - INTEGER
+ Time, in seconds, that cached PMTU information is kept.
+
+min_adv_mss - INTEGER
+ The advertised MSS depends on the first hop route MTU, but will
+ never be lower than this setting.
+
+IP Fragmentation:
+
+ipfrag_high_thresh - INTEGER
+ Maximum memory used to reassemble IP fragments. When
+ ipfrag_high_thresh bytes of memory is allocated for this purpose,
+ the fragment handler will toss packets until ipfrag_low_thresh
+ is reached.
+
+ipfrag_low_thresh - INTEGER
+ See ipfrag_high_thresh
+
+ipfrag_time - INTEGER
+ Time in seconds to keep an IP fragment in memory.
+
+ipfrag_secret_interval - INTEGER
+ Regeneration interval (in seconds) of the hash secret (or lifetime
+ for the hash secret) for IP fragments.
+ Default: 600
+
+INET peer storage:
+
+inet_peer_threshold - INTEGER
+ The approximate size of the storage. Starting from this threshold
+ entries will be thrown aggressively. This threshold also determines
+ entries' time-to-live and time intervals between garbage collection
+ passes. More entries, less time-to-live, less GC interval.
+
+inet_peer_minttl - INTEGER
+ Minimum time-to-live of entries. Should be enough to cover fragment
+ time-to-live on the reassembling side. This minimum time-to-live is
+ guaranteed if the pool size is less than inet_peer_threshold.
+ Measured in jiffies(1).
+
+inet_peer_maxttl - INTEGER
+ Maximum time-to-live of entries. Unused entries will expire after
+ this period of time if there is no memory pressure on the pool (i.e.
+ when the number of entries in the pool is very small).
+ Measured in jiffies(1).
+
+inet_peer_gc_mintime - INTEGER
+ Minimum interval between garbage collection passes. This interval is
+ in effect under high memory pressure on the pool.
+ Measured in jiffies(1).
+
+inet_peer_gc_maxtime - INTEGER
+ Minimum interval between garbage collection passes. This interval is
+ in effect under low (or absent) memory pressure on the pool.
+ Measured in jiffies(1).
+
+TCP variables:
+
+tcp_syn_retries - INTEGER
+ Number of times initial SYNs for an active TCP connection attempt
+ will be retransmitted. Should not be higher than 255. Default value
+ is 5, which corresponds to ~180seconds.
+
+tcp_synack_retries - INTEGER
+ Number of times SYNACKs for a passive TCP connection attempt will
+ be retransmitted. Should not be higher than 255. Default value
+ is 5, which corresponds to ~180seconds.
+
+tcp_keepalive_time - INTEGER
+ How often TCP sends out keepalive messages when keepalive is enabled.
+ Default: 2hours.
+
+tcp_keepalive_probes - INTEGER
+ How many keepalive probes TCP sends out, until it decides that the
+ connection is broken. Default value: 9.
+
+tcp_keepalive_intvl - INTEGER
+ How frequently the probes are send out. Multiplied by
+ tcp_keepalive_probes it is time to kill not responding connection,
+ after probes started. Default value: 75sec i.e. connection
+ will be aborted after ~11 minutes of retries.
+
+tcp_retries1 - INTEGER
+ How many times to retry before deciding that something is wrong
+ and it is necessary to report this suspicion to network layer.
+ Minimal RFC value is 3, it is default, which corresponds
+ to ~3sec-8min depending on RTO.
+
+tcp_retries2 - INTEGER
+ How may times to retry before killing alive TCP connection.
+ RFC1122 says that the limit should be longer than 100 sec.
+ It is too small number. Default value 15 corresponds to ~13-30min
+ depending on RTO.
+
+tcp_orphan_retries - INTEGER
+ How may times to retry before killing TCP connection, closed
+ by our side. Default value 7 corresponds to ~50sec-16min
+ depending on RTO. If you machine is loaded WEB server,
+ you should think about lowering this value, such sockets
+ may consume significant resources. Cf. tcp_max_orphans.
+
+tcp_fin_timeout - INTEGER
+ Time to hold socket in state FIN-WAIT-2, if it was closed
+ by our side. Peer can be broken and never close its side,
+ or even died unexpectedly. Default value is 60sec.
+ Usual value used in 2.2 was 180 seconds, you may restore
+ it, but remember that if your machine is even underloaded WEB server,
+ you risk to overflow memory with kilotons of dead sockets,
+ FIN-WAIT-2 sockets are less dangerous than FIN-WAIT-1,
+ because they eat maximum 1.5K of memory, but they tend
+ to live longer. Cf. tcp_max_orphans.
+
+tcp_max_tw_buckets - INTEGER
+ Maximal number of timewait sockets held by system simultaneously.
+ If this number is exceeded time-wait socket is immediately destroyed
+ and warning is printed. This limit exists only to prevent
+ simple DoS attacks, you _must_ not lower the limit artificially,
+ but rather increase it (probably, after increasing installed memory),
+ if network conditions require more than default value.
+
+tcp_tw_recycle - BOOLEAN
+ Enable fast recycling TIME-WAIT sockets. Default value is 0.
+ It should not be changed without advice/request of technical
+ experts.
+
+tcp_tw_reuse - BOOLEAN
+ Allow to reuse TIME-WAIT sockets for new connections when it is
+ safe from protocol viewpoint. Default value is 0.
+ It should not be changed without advice/request of technical
+ experts.
+
+tcp_max_orphans - INTEGER
+ Maximal number of TCP sockets not attached to any user file handle,
+ held by system. If this number is exceeded orphaned connections are
+ reset immediately and warning is printed. This limit exists
+ only to prevent simple DoS attacks, you _must_ not rely on this
+ or lower the limit artificially, but rather increase it
+ (probably, after increasing installed memory),
+ if network conditions require more than default value,
+ and tune network services to linger and kill such states
+ more aggressively. Let me to remind again: each orphan eats
+ up to ~64K of unswappable memory.
+
+tcp_abort_on_overflow - BOOLEAN
+ If listening service is too slow to accept new connections,
+ reset them. Default state is FALSE. It means that if overflow
+ occurred due to a burst, connection will recover. Enable this
+ option _only_ if you are really sure that listening daemon
+ cannot be tuned to accept connections faster. Enabling this
+ option can harm clients of your server.
+
+tcp_syncookies - BOOLEAN
+ Only valid when the kernel was compiled with CONFIG_SYNCOOKIES
+ Send out syncookies when the syn backlog queue of a socket
+ overflows. This is to prevent against the common 'syn flood attack'
+ Default: FALSE
+
+ Note, that syncookies is fallback facility.
+ It MUST NOT be used to help highly loaded servers to stand
+ against legal connection rate. If you see synflood warnings
+ in your logs, but investigation shows that they occur
+ because of overload with legal connections, you should tune
+ another parameters until this warning disappear.
+ See: tcp_max_syn_backlog, tcp_synack_retries, tcp_abort_on_overflow.
+
+ syncookies seriously violate TCP protocol, do not allow
+ to use TCP extensions, can result in serious degradation
+ of some services (f.e. SMTP relaying), visible not by you,
+ but your clients and relays, contacting you. While you see
+ synflood warnings in logs not being really flooded, your server
+ is seriously misconfigured.
+
+tcp_stdurg - BOOLEAN
+ Use the Host requirements interpretation of the TCP urg pointer field.
+ Most hosts use the older BSD interpretation, so if you turn this on
+ Linux might not communicate correctly with them.
+ Default: FALSE
+
+tcp_max_syn_backlog - INTEGER
+ Maximal number of remembered connection requests, which are
+ still did not receive an acknowledgment from connecting client.
+ Default value is 1024 for systems with more than 128Mb of memory,
+ and 128 for low memory machines. If server suffers of overload,
+ try to increase this number.
+
+tcp_window_scaling - BOOLEAN
+ Enable window scaling as defined in RFC1323.
+
+tcp_timestamps - BOOLEAN
+ Enable timestamps as defined in RFC1323.
+
+tcp_sack - BOOLEAN
+ Enable select acknowledgments (SACKS).
+
+tcp_fack - BOOLEAN
+ Enable FACK congestion avoidance and fast retransmission.
+ The value is not used, if tcp_sack is not enabled.
+
+tcp_dsack - BOOLEAN
+ Allows TCP to send "duplicate" SACKs.
+
+tcp_ecn - BOOLEAN
+ Enable Explicit Congestion Notification in TCP.
+
+tcp_reordering - INTEGER
+ Maximal reordering of packets in a TCP stream.
+ Default: 3
+
+tcp_retrans_collapse - BOOLEAN
+ Bug-to-bug compatibility with some broken printers.
+ On retransmit try to send bigger packets to work around bugs in
+ certain TCP stacks.
+
+tcp_wmem - vector of 3 INTEGERs: min, default, max
+ min: Amount of memory reserved for send buffers for TCP socket.
+ Each TCP socket has rights to use it due to fact of its birth.
+ Default: 4K
+
+ default: Amount of memory allowed for send buffers for TCP socket
+ by default. This value overrides net.core.wmem_default used
+ by other protocols, it is usually lower than net.core.wmem_default.
+ Default: 16K
+
+ max: Maximal amount of memory allowed for automatically selected
+ send buffers for TCP socket. This value does not override
+ net.core.wmem_max, "static" selection via SO_SNDBUF does not use this.
+ Default: 128K
+
+tcp_rmem - vector of 3 INTEGERs: min, default, max
+ min: Minimal size of receive buffer used by TCP sockets.
+ It is guaranteed to each TCP socket, even under moderate memory
+ pressure.
+ Default: 8K
+
+ default: default size of receive buffer used by TCP sockets.
+ This value overrides net.core.rmem_default used by other protocols.
+ Default: 87380 bytes. This value results in window of 65535 with
+ default setting of tcp_adv_win_scale and tcp_app_win:0 and a bit
+ less for default tcp_app_win. See below about these variables.
+
+ max: maximal size of receive buffer allowed for automatically
+ selected receiver buffers for TCP socket. This value does not override
+ net.core.rmem_max, "static" selection via SO_RCVBUF does not use this.
+ Default: 87380*2 bytes.
+
+tcp_mem - vector of 3 INTEGERs: min, pressure, max
+ low: below this number of pages TCP is not bothered about its
+ memory appetite.
+
+ pressure: when amount of memory allocated by TCP exceeds this number
+ of pages, TCP moderates its memory consumption and enters memory
+ pressure mode, which is exited when memory consumption falls
+ under "low".
+
+ high: number of pages allowed for queueing by all TCP sockets.
+
+ Defaults are calculated at boot time from amount of available
+ memory.
+
+tcp_app_win - INTEGER
+ Reserve max(window/2^tcp_app_win, mss) of window for application
+ buffer. Value 0 is special, it means that nothing is reserved.
+ Default: 31
+
+tcp_adv_win_scale - INTEGER
+ Count buffering overhead as bytes/2^tcp_adv_win_scale
+ (if tcp_adv_win_scale > 0) or bytes-bytes/2^(-tcp_adv_win_scale),
+ if it is <= 0.
+ Default: 2
+
+tcp_rfc1337 - BOOLEAN
+ If set, the TCP stack behaves conforming to RFC1337. If unset,
+ we are not conforming to RFC, but prevent TCP TIME_WAIT
+ assassination.
+ Default: 0
+
+tcp_low_latency - BOOLEAN
+ If set, the TCP stack makes decisions that prefer lower
+ latency as opposed to higher throughput. By default, this
+ option is not set meaning that higher throughput is preferred.
+ An example of an application where this default should be
+ changed would be a Beowulf compute cluster.
+ Default: 0
+
+tcp_westwood - BOOLEAN
+ Enable TCP Westwood+ congestion control algorithm.
+ TCP Westwood+ is a sender-side only modification of the TCP Reno
+ protocol stack that optimizes the performance of TCP congestion
+ control. It is based on end-to-end bandwidth estimation to set
+ congestion window and slow start threshold after a congestion
+ episode. Using this estimation, TCP Westwood+ adaptively sets a
+ slow start threshold and a congestion window which takes into
+ account the bandwidth used at the time congestion is experienced.
+ TCP Westwood+ significantly increases fairness wrt TCP Reno in
+ wired networks and throughput over wireless links.
+ Default: 0
+
+tcp_vegas_cong_avoid - BOOLEAN
+ Enable TCP Vegas congestion avoidance algorithm.
+ TCP Vegas is a sender-side only change to TCP that anticipates
+ the onset of congestion by estimating the bandwidth. TCP Vegas
+ adjusts the sending rate by modifying the congestion
+ window. TCP Vegas should provide less packet loss, but it is
+ not as aggressive as TCP Reno.
+ Default:0
+
+tcp_bic - BOOLEAN
+ Enable BIC TCP congestion control algorithm.
+ BIC-TCP is a sender-side only change that ensures a linear RTT
+ fairness under large windows while offering both scalability and
+ bounded TCP-friendliness. The protocol combines two schemes
+ called additive increase and binary search increase. When the
+ congestion window is large, additive increase with a large
+ increment ensures linear RTT fairness as well as good
+ scalability. Under small congestion windows, binary search
+ increase provides TCP friendliness.
+ Default: 0
+
+tcp_bic_low_window - INTEGER
+ Sets the threshold window (in packets) where BIC TCP starts to
+ adjust the congestion window. Below this threshold BIC TCP behaves
+ the same as the default TCP Reno.
+ Default: 14
+
+tcp_bic_fast_convergence - BOOLEAN
+ Forces BIC TCP to more quickly respond to changes in congestion
+ window. Allows two flows sharing the same connection to converge
+ more rapidly.
+ Default: 1
+
+tcp_default_win_scale - INTEGER
+ Sets the minimum window scale TCP will negotiate for on all
+ conections.
+ Default: 7
+
+tcp_tso_win_divisor - INTEGER
+ This allows control over what percentage of the congestion window
+ can be consumed by a single TSO frame.
+ The setting of this parameter is a choice between burstiness and
+ building larger TSO frames.
+ Default: 8
+
+tcp_frto - BOOLEAN
+ Enables F-RTO, an enhanced recovery algorithm for TCP retransmission
+ timeouts. It is particularly beneficial in wireless environments
+ where packet loss is typically due to random radio interference
+ rather than intermediate router congestion.
+
+somaxconn - INTEGER
+ Limit of socket listen() backlog, known in userspace as SOMAXCONN.
+ Defaults to 128. See also tcp_max_syn_backlog for additional tuning
+ for TCP sockets.
+
+IP Variables:
+
+ip_local_port_range - 2 INTEGERS
+ Defines the local port range that is used by TCP and UDP to
+ choose the local port. The first number is the first, the
+ second the last local port number. Default value depends on
+ amount of memory available on the system:
+ > 128Mb 32768-61000
+ < 128Mb 1024-4999 or even less.
+ This number defines number of active connections, which this
+ system can issue simultaneously to systems not supporting
+ TCP extensions (timestamps). With tcp_tw_recycle enabled
+ (i.e. by default) range 1024-4999 is enough to issue up to
+ 2000 connections per second to systems supporting timestamps.
+
+ip_nonlocal_bind - BOOLEAN
+ If set, allows processes to bind() to non-local IP addresses,
+ which can be quite useful - but may break some applications.
+ Default: 0
+
+ip_dynaddr - BOOLEAN
+ If set non-zero, enables support for dynamic addresses.
+ If set to a non-zero value larger than 1, a kernel log
+ message will be printed when dynamic address rewriting
+ occurs.
+ Default: 0
+
+icmp_echo_ignore_all - BOOLEAN
+icmp_echo_ignore_broadcasts - BOOLEAN
+ If either is set to true, then the kernel will ignore either all
+ ICMP ECHO requests sent to it or just those to broadcast/multicast
+ addresses, respectively.
+
+icmp_ratelimit - INTEGER
+ Limit the maximal rates for sending ICMP packets whose type matches
+ icmp_ratemask (see below) to specific targets.
+ 0 to disable any limiting, otherwise the maximal rate in jiffies(1)
+ Default: 100
+
+icmp_ratemask - INTEGER
+ Mask made of ICMP types for which rates are being limited.
+ Significant bits: IHGFEDCBA9876543210
+ Default mask: 0000001100000011000 (6168)
+
+ Bit definitions (see include/linux/icmp.h):
+ 0 Echo Reply
+ 3 Destination Unreachable *
+ 4 Source Quench *
+ 5 Redirect
+ 8 Echo Request
+ B Time Exceeded *
+ C Parameter Problem *
+ D Timestamp Request
+ E Timestamp Reply
+ F Info Request
+ G Info Reply
+ H Address Mask Request
+ I Address Mask Reply
+
+ * These are rate limited by default (see default mask above)
+
+icmp_ignore_bogus_error_responses - BOOLEAN
+ Some routers violate RFC1122 by sending bogus responses to broadcast
+ frames. Such violations are normally logged via a kernel warning.
+ If this is set to TRUE, the kernel will not give such warnings, which
+ will avoid log file clutter.
+ Default: FALSE
+
+igmp_max_memberships - INTEGER
+ Change the maximum number of multicast groups we can subscribe to.
+ Default: 20
+
+conf/interface/* changes special settings per interface (where "interface" is
+ the name of your network interface)
+conf/all/* is special, changes the settings for all interfaces
+
+
+log_martians - BOOLEAN
+ Log packets with impossible addresses to kernel log.
+ log_martians for the interface will be enabled if at least one of
+ conf/{all,interface}/log_martians is set to TRUE,
+ it will be disabled otherwise
+
+accept_redirects - BOOLEAN
+ Accept ICMP redirect messages.
+ accept_redirects for the interface will be enabled if:
+ - both conf/{all,interface}/accept_redirects are TRUE in the case forwarding
+ for the interface is enabled
+ or
+ - at least one of conf/{all,interface}/accept_redirects is TRUE in the case
+ forwarding for the interface is disabled
+ accept_redirects for the interface will be disabled otherwise
+ default TRUE (host)
+ FALSE (router)
+
+forwarding - BOOLEAN
+ Enable IP forwarding on this interface.
+
+mc_forwarding - BOOLEAN
+ Do multicast routing. The kernel needs to be compiled with CONFIG_MROUTE
+ and a multicast routing daemon is required.
+ conf/all/mc_forwarding must also be set to TRUE to enable multicast routing
+ for the interface
+
+medium_id - INTEGER
+ Integer value used to differentiate the devices by the medium they
+ are attached to. Two devices can have different id values when
+ the broadcast packets are received only on one of them.
+ The default value 0 means that the device is the only interface
+ to its medium, value of -1 means that medium is not known.
+
+ Currently, it is used to change the proxy_arp behavior:
+ the proxy_arp feature is enabled for packets forwarded between
+ two devices attached to different media.
+
+proxy_arp - BOOLEAN
+ Do proxy arp.
+ proxy_arp for the interface will be enabled if at least one of
+ conf/{all,interface}/proxy_arp is set to TRUE,
+ it will be disabled otherwise
+
+shared_media - BOOLEAN
+ Send(router) or accept(host) RFC1620 shared media redirects.
+ Overrides ip_secure_redirects.
+ shared_media for the interface will be enabled if at least one of
+ conf/{all,interface}/shared_media is set to TRUE,
+ it will be disabled otherwise
+ default TRUE
+
+secure_redirects - BOOLEAN
+ Accept ICMP redirect messages only for gateways,
+ listed in default gateway list.
+ secure_redirects for the interface will be enabled if at least one of
+ conf/{all,interface}/secure_redirects is set to TRUE,
+ it will be disabled otherwise
+ default TRUE
+
+send_redirects - BOOLEAN
+ Send redirects, if router.
+ send_redirects for the interface will be enabled if at least one of
+ conf/{all,interface}/send_redirects is set to TRUE,
+ it will be disabled otherwise
+ Default: TRUE
+
+bootp_relay - BOOLEAN
+ Accept packets with source address 0.b.c.d destined
+ not to this host as local ones. It is supposed, that
+ BOOTP relay daemon will catch and forward such packets.
+ conf/all/bootp_relay must also be set to TRUE to enable BOOTP relay
+ for the interface
+ default FALSE
+ Not Implemented Yet.
+
+accept_source_route - BOOLEAN
+ Accept packets with SRR option.
+ conf/all/accept_source_route must also be set to TRUE to accept packets
+ with SRR option on the interface
+ default TRUE (router)
+ FALSE (host)
+
+rp_filter - BOOLEAN
+ 1 - do source validation by reversed path, as specified in RFC1812
+ Recommended option for single homed hosts and stub network
+ routers. Could cause troubles for complicated (not loop free)
+ networks running a slow unreliable protocol (sort of RIP),
+ or using static routes.
+
+ 0 - No source validation.
+
+ conf/all/rp_filter must also be set to TRUE to do source validation
+ on the interface
+
+ Default value is 0. Note that some distributions enable it
+ in startup scripts.
+
+arp_filter - BOOLEAN
+ 1 - Allows you to have multiple network interfaces on the same
+ subnet, and have the ARPs for each interface be answered
+ based on whether or not the kernel would route a packet from
+ the ARP'd IP out that interface (therefore you must use source
+ based routing for this to work). In other words it allows control
+ of which cards (usually 1) will respond to an arp request.
+
+ 0 - (default) The kernel can respond to arp requests with addresses
+ from other interfaces. This may seem wrong but it usually makes
+ sense, because it increases the chance of successful communication.
+ IP addresses are owned by the complete host on Linux, not by
+ particular interfaces. Only for more complex setups like load-
+ balancing, does this behaviour cause problems.
+
+ arp_filter for the interface will be enabled if at least one of
+ conf/{all,interface}/arp_filter is set to TRUE,
+ it will be disabled otherwise
+
+arp_announce - INTEGER
+ Define different restriction levels for announcing the local
+ source IP address from IP packets in ARP requests sent on
+ interface:
+ 0 - (default) Use any local address, configured on any interface
+ 1 - Try to avoid local addresses that are not in the target's
+ subnet for this interface. This mode is useful when target
+ hosts reachable via this interface require the source IP
+ address in ARP requests to be part of their logical network
+ configured on the receiving interface. When we generate the
+ request we will check all our subnets that include the
+ target IP and will preserve the source address if it is from
+ such subnet. If there is no such subnet we select source
+ address according to the rules for level 2.
+ 2 - Always use the best local address for this target.
+ In this mode we ignore the source address in the IP packet
+ and try to select local address that we prefer for talks with
+ the target host. Such local address is selected by looking
+ for primary IP addresses on all our subnets on the outgoing
+ interface that include the target IP address. If no suitable
+ local address is found we select the first local address
+ we have on the outgoing interface or on all other interfaces,
+ with the hope we will receive reply for our request and
+ even sometimes no matter the source IP address we announce.
+
+ The max value from conf/{all,interface}/arp_announce is used.
+
+ Increasing the restriction level gives more chance for
+ receiving answer from the resolved target while decreasing
+ the level announces more valid sender's information.
+
+arp_ignore - INTEGER
+ Define different modes for sending replies in response to
+ received ARP requests that resolve local target IP addresses:
+ 0 - (default): reply for any local target IP address, configured
+ on any interface
+ 1 - reply only if the target IP address is local address
+ configured on the incoming interface
+ 2 - reply only if the target IP address is local address
+ configured on the incoming interface and both with the
+ sender's IP address are part from same subnet on this interface
+ 3 - do not reply for local addresses configured with scope host,
+ only resolutions for global and link addresses are replied
+ 4-7 - reserved
+ 8 - do not reply for all local addresses
+
+ The max value from conf/{all,interface}/arp_ignore is used
+ when ARP request is received on the {interface}
+
+app_solicit - INTEGER
+ The maximum number of probes to send to the user space ARP daemon
+ via netlink before dropping back to multicast probes (see
+ mcast_solicit). Defaults to 0.
+
+disable_policy - BOOLEAN
+ Disable IPSEC policy (SPD) for this interface
+
+disable_xfrm - BOOLEAN
+ Disable IPSEC encryption on this interface, whatever the policy
+
+
+
+tag - INTEGER
+ Allows you to write a number, which can be used as required.
+ Default value is 0.
+
+(1) Jiffie: internal timeunit for the kernel. On the i386 1/100s, on the
+Alpha 1/1024s. See the HZ define in /usr/include/asm/param.h for the exact
+value on your system.
+
+Alexey Kuznetsov.
+kuznet@ms2.inr.ac.ru
+
+Updated by:
+Andi Kleen
+ak@muc.de
+Nicolas Delon
+delon.nicolas@wanadoo.fr
+
+
+
+
+/proc/sys/net/ipv6/* Variables:
+
+IPv6 has no global variables such as tcp_*. tcp_* settings under ipv4/ also
+apply to IPv6 [XXX?].
+
+bindv6only - BOOLEAN
+ Default value for IPV6_V6ONLY socket option,
+ which restricts use of the IPv6 socket to IPv6 communication
+ only.
+ TRUE: disable IPv4-mapped address feature
+ FALSE: enable IPv4-mapped address feature
+
+ Default: FALSE (as specified in RFC2553bis)
+
+IPv6 Fragmentation:
+
+ip6frag_high_thresh - INTEGER
+ Maximum memory used to reassemble IPv6 fragments. When
+ ip6frag_high_thresh bytes of memory is allocated for this purpose,
+ the fragment handler will toss packets until ip6frag_low_thresh
+ is reached.
+
+ip6frag_low_thresh - INTEGER
+ See ip6frag_high_thresh
+
+ip6frag_time - INTEGER
+ Time in seconds to keep an IPv6 fragment in memory.
+
+ip6frag_secret_interval - INTEGER
+ Regeneration interval (in seconds) of the hash secret (or lifetime
+ for the hash secret) for IPv6 fragments.
+ Default: 600
+
+conf/default/*:
+ Change the interface-specific default settings.
+
+
+conf/all/*:
+ Change all the interface-specific settings.
+
+ [XXX: Other special features than forwarding?]
+
+conf/all/forwarding - BOOLEAN
+ Enable global IPv6 forwarding between all interfaces.
+
+ IPv4 and IPv6 work differently here; e.g. netfilter must be used
+ to control which interfaces may forward packets and which not.
+
+ This also sets all interfaces' Host/Router setting
+ 'forwarding' to the specified value. See below for details.
+
+ This referred to as global forwarding.
+
+conf/interface/*:
+ Change special settings per interface.
+
+ The functional behaviour for certain settings is different
+ depending on whether local forwarding is enabled or not.
+
+accept_ra - BOOLEAN
+ Accept Router Advertisements; autoconfigure using them.
+
+ Functional default: enabled if local forwarding is disabled.
+ disabled if local forwarding is enabled.
+
+accept_redirects - BOOLEAN
+ Accept Redirects.
+
+ Functional default: enabled if local forwarding is disabled.
+ disabled if local forwarding is enabled.
+
+autoconf - BOOLEAN
+ Autoconfigure addresses using Prefix Information in Router
+ Advertisements.
+
+ Functional default: enabled if accept_ra is enabled.
+ disabled if accept_ra is disabled.
+
+dad_transmits - INTEGER
+ The amount of Duplicate Address Detection probes to send.
+ Default: 1
+
+forwarding - BOOLEAN
+ Configure interface-specific Host/Router behaviour.
+
+ Note: It is recommended to have the same setting on all
+ interfaces; mixed router/host scenarios are rather uncommon.
+
+ FALSE:
+
+ By default, Host behaviour is assumed. This means:
+
+ 1. IsRouter flag is not set in Neighbour Advertisements.
+ 2. Router Solicitations are being sent when necessary.
+ 3. If accept_ra is TRUE (default), accept Router
+ Advertisements (and do autoconfiguration).
+ 4. If accept_redirects is TRUE (default), accept Redirects.
+
+ TRUE:
+
+ If local forwarding is enabled, Router behaviour is assumed.
+ This means exactly the reverse from the above:
+
+ 1. IsRouter flag is set in Neighbour Advertisements.
+ 2. Router Solicitations are not sent.
+ 3. Router Advertisements are ignored.
+ 4. Redirects are ignored.
+
+ Default: FALSE if global forwarding is disabled (default),
+ otherwise TRUE.
+
+hop_limit - INTEGER
+ Default Hop Limit to set.
+ Default: 64
+
+mtu - INTEGER
+ Default Maximum Transfer Unit
+ Default: 1280 (IPv6 required minimum)
+
+router_solicitation_delay - INTEGER
+ Number of seconds to wait after interface is brought up
+ before sending Router Solicitations.
+ Default: 1
+
+router_solicitation_interval - INTEGER
+ Number of seconds to wait between Router Solicitations.
+ Default: 4
+
+router_solicitations - INTEGER
+ Number of Router Solicitations to send until assuming no
+ routers are present.
+ Default: 3
+
+use_tempaddr - INTEGER
+ Preference for Privacy Extensions (RFC3041).
+ <= 0 : disable Privacy Extensions
+ == 1 : enable Privacy Extensions, but prefer public
+ addresses over temporary addresses.
+ > 1 : enable Privacy Extensions and prefer temporary
+ addresses over public addresses.
+ Default: 0 (for most devices)
+ -1 (for point-to-point devices and loopback devices)
+
+temp_valid_lft - INTEGER
+ valid lifetime (in seconds) for temporary addresses.
+ Default: 604800 (7 days)
+
+temp_prefered_lft - INTEGER
+ Preferred lifetime (in seconds) for temporary addresses.
+ Default: 86400 (1 day)
+
+max_desync_factor - INTEGER
+ Maximum value for DESYNC_FACTOR, which is a random value
+ that ensures that clients don't synchronize with each
+ other and generate new addresses at exactly the same time.
+ value is in seconds.
+ Default: 600
+
+regen_max_retry - INTEGER
+ Number of attempts before give up attempting to generate
+ valid temporary addresses.
+ Default: 5
+
+max_addresses - INTEGER
+ Number of maximum addresses per interface. 0 disables limitation.
+ It is recommended not set too large value (or 0) because it would
+ be too easy way to crash kernel to allow to create too much of
+ autoconfigured addresses.
+ Default: 16
+
+icmp/*:
+ratelimit - INTEGER
+ Limit the maximal rates for sending ICMPv6 packets.
+ 0 to disable any limiting, otherwise the maximal rate in jiffies(1)
+ Default: 100
+
+
+IPv6 Update by:
+Pekka Savola <pekkas@netcore.fi>
+YOSHIFUJI Hideaki / USAGI Project <yoshfuji@linux-ipv6.org>
+
+
+/proc/sys/net/bridge/* Variables:
+
+bridge-nf-call-arptables - BOOLEAN
+ 1 : pass bridged ARP traffic to arptables' FORWARD chain.
+ 0 : disable this.
+ Default: 1
+
+bridge-nf-call-iptables - BOOLEAN
+ 1 : pass bridged IPv4 traffic to iptables' chains.
+ 0 : disable this.
+ Default: 1
+
+bridge-nf-call-ip6tables - BOOLEAN
+ 1 : pass bridged IPv6 traffic to ip6tables' chains.
+ 0 : disable this.
+ Default: 1
+
+bridge-nf-filter-vlan-tagged - BOOLEAN
+ 1 : pass bridged vlan-tagged ARP/IP traffic to arptables/iptables.
+ 0 : disable this.
+ Default: 1
+
+
+UNDOCUMENTED:
+
+dev_weight FIXME
+discovery_slots FIXME
+discovery_timeout FIXME
+fast_poll_increase FIXME
+ip6_queue_maxlen FIXME
+lap_keepalive_time FIXME
+lo_cong FIXME
+max_baud_rate FIXME
+max_dgram_qlen FIXME
+max_noreply_time FIXME
+max_tx_data_size FIXME
+max_tx_window FIXME
+min_tx_turn_time FIXME
+mod_cong FIXME
+no_cong FIXME
+no_cong_thresh FIXME
+slot_timeout FIXME
+warn_noreply_time FIXME
+
+$Id: ip-sysctl.txt,v 1.20 2001/12/13 09:00:18 davem Exp $