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linux/Documentation/networking/nf_conntrack-sysctl.txt

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netfilter: doc: add nf_conntrack sysctl api documentation I grepped through the code and picked bits about nf_conntrack sysctl api and put that into one documentation file. [ I have mangled this patch including comments from several grammar improvements proposed by Neal Murphy <neal.p.murphy@alum.wpi.edu>, any new grammar error is my mistake --pablo ] Signed-off-by: Jiri Pirko <jiri@resnulli.us> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-01-18 03:05:08 +04:00
/proc/sys/net/netfilter/nf_conntrack_* Variables:
nf_conntrack_acct - BOOLEAN
0 - disabled (default)
not 0 - enabled
Enable connection tracking flow accounting. 64-bit byte and packet
counters per flow are added.
netfilter: conntrack: allow increasing bucket size via sysctl too No need to restrict this to module parameter. We export a copy of the real hash size -- when user alters the value we allocate the new table, copy entries etc before we update the real size to the requested one. This is also needed because the real size is used by concurrent readers and cannot be changed without synchronizing the conntrack generation seqcnt. We only allow changing this value from the initial net namespace. Tested using http-client-benchmark vs. httpterm with concurrent while true;do echo $RANDOM > /proc/sys/net/netfilter/nf_conntrack_buckets done Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-06-22 14:26:10 +03:00
nf_conntrack_buckets - INTEGER
netfilter: doc: add nf_conntrack sysctl api documentation I grepped through the code and picked bits about nf_conntrack sysctl api and put that into one documentation file. [ I have mangled this patch including comments from several grammar improvements proposed by Neal Murphy <neal.p.murphy@alum.wpi.edu>, any new grammar error is my mistake --pablo ] Signed-off-by: Jiri Pirko <jiri@resnulli.us> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-01-18 03:05:08 +04:00
Size of hash table. If not specified as parameter during module
loading, the default size is calculated by dividing total memory
by 16384 to determine the number of buckets but the hash table will
netfilter: conntrack: adjust nf_conntrack_buckets default value Manually bumping either nf_conntrack_buckets or nf_conntrack_max has become a common task as our Linux servers tend to serve more and more clients/applications, so let's adjust nf_conntrack_buckets this to a more updated value. Now for systems with more than 4GB of memory, nf_conntrack_buckets becomes 65536 instead of 16384, resulting in nf_conntrack_max=256k entries. Signed-off-by: Marcelo Ricardo Leitner <mleitner@redhat.com> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-12-03 22:30:19 +03:00
never have fewer than 32 and limited to 16384 buckets. For systems
with more than 4GB of memory it will be 65536 buckets.
netfilter: conntrack: allow increasing bucket size via sysctl too No need to restrict this to module parameter. We export a copy of the real hash size -- when user alters the value we allocate the new table, copy entries etc before we update the real size to the requested one. This is also needed because the real size is used by concurrent readers and cannot be changed without synchronizing the conntrack generation seqcnt. We only allow changing this value from the initial net namespace. Tested using http-client-benchmark vs. httpterm with concurrent while true;do echo $RANDOM > /proc/sys/net/netfilter/nf_conntrack_buckets done Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-06-22 14:26:10 +03:00
This sysctl is only writeable in the initial net namespace.
netfilter: doc: add nf_conntrack sysctl api documentation I grepped through the code and picked bits about nf_conntrack sysctl api and put that into one documentation file. [ I have mangled this patch including comments from several grammar improvements proposed by Neal Murphy <neal.p.murphy@alum.wpi.edu>, any new grammar error is my mistake --pablo ] Signed-off-by: Jiri Pirko <jiri@resnulli.us> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-01-18 03:05:08 +04:00
nf_conntrack_checksum - BOOLEAN
0 - disabled
not 0 - enabled (default)
Verify checksum of incoming packets. Packets with bad checksums are
in INVALID state. If this is enabled, such packets will not be
considered for connection tracking.
nf_conntrack_count - INTEGER (read-only)
Number of currently allocated flow entries.
nf_conntrack_events - BOOLEAN
0 - disabled
not 0 - enabled (default)
If this option is enabled, the connection tracking code will
provide userspace with connection tracking events via ctnetlink.
nf_conntrack_expect_max - INTEGER
Maximum size of expectation table. Default value is
nf_conntrack_buckets / 256. Minimum is 1.
nf_conntrack_frag6_high_thresh - INTEGER
default 262144
Maximum memory used to reassemble IPv6 fragments. When
nf_conntrack_frag6_high_thresh bytes of memory is allocated for this
purpose, the fragment handler will toss packets until
nf_conntrack_frag6_low_thresh is reached.
nf_conntrack_frag6_low_thresh - INTEGER
default 196608
See nf_conntrack_frag6_low_thresh
nf_conntrack_frag6_timeout - INTEGER (seconds)
default 60
Time to keep an IPv6 fragment in memory.
nf_conntrack_generic_timeout - INTEGER (seconds)
default 600
Default for generic timeout. This refers to layer 4 unknown/unsupported
protocols.
nf_conntrack_helper - BOOLEAN
netfilter: fix nf_conntrack_helper documentation Since kernel 4.7 this defaults to off. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-11-10 16:24:40 +03:00
0 - disabled (default)
not 0 - enabled
netfilter: doc: add nf_conntrack sysctl api documentation I grepped through the code and picked bits about nf_conntrack sysctl api and put that into one documentation file. [ I have mangled this patch including comments from several grammar improvements proposed by Neal Murphy <neal.p.murphy@alum.wpi.edu>, any new grammar error is my mistake --pablo ] Signed-off-by: Jiri Pirko <jiri@resnulli.us> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-01-18 03:05:08 +04:00
Enable automatic conntrack helper assignment.
netfilter: fix nf_conntrack_helper documentation Since kernel 4.7 this defaults to off. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-11-10 16:24:40 +03:00
If disabled it is required to set up iptables rules to assign
helpers to connections. See the CT target description in the
iptables-extensions(8) man page for further information.
netfilter: doc: add nf_conntrack sysctl api documentation I grepped through the code and picked bits about nf_conntrack sysctl api and put that into one documentation file. [ I have mangled this patch including comments from several grammar improvements proposed by Neal Murphy <neal.p.murphy@alum.wpi.edu>, any new grammar error is my mistake --pablo ] Signed-off-by: Jiri Pirko <jiri@resnulli.us> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-01-18 03:05:08 +04:00
nf_conntrack_icmp_timeout - INTEGER (seconds)
default 30
Default for ICMP timeout.
nf_conntrack_icmpv6_timeout - INTEGER (seconds)
default 30
Default for ICMP6 timeout.
nf_conntrack_log_invalid - INTEGER
0 - disable (default)
1 - log ICMP packets
6 - log TCP packets
17 - log UDP packets
33 - log DCCP packets
41 - log ICMPv6 packets
136 - log UDPLITE packets
255 - log packets of any protocol
Log invalid packets of a type specified by value.
nf_conntrack_max - INTEGER
Size of connection tracking table. Default value is
nf_conntrack_buckets value * 4.
netfilter: conntrack: add nf_conntrack_default_on sysctl This switch (default on) can be used to disable automatic registration of connection tracking functionality in newly created network namespaces. This means that when net namespace goes down (or the tracker protocol module is unloaded) we *might* have to unregister the hooks. We can either add another per-netns variable that tells if the hooks got registered by default, or, alternatively, just call the protocol _put() function and have the callee deal with a possible 'extra' put() operation that doesn't pair with a get() one. This uses the latter approach, i.e. a put() without a get has no effect. Conntrack is still enabled automatically regardless of the new sysctl setting if the new net namespace requires connection tracking, e.g. when NAT rules are created. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-11-15 23:36:44 +03:00
nf_conntrack_default_on - BOOLEAN
0 - don't register conntrack in new net namespaces
1 - register conntrack in new net namespaces (default)
This controls wheter newly created network namespaces have connection
tracking enabled by default. It will be enabled automatically
regardless of this setting if the new net namespace requires
connection tracking, e.g. when NAT rules are created.
This setting is only visible in initial user namespace, it has no
effect on existing namespaces.
netfilter: doc: add nf_conntrack sysctl api documentation I grepped through the code and picked bits about nf_conntrack sysctl api and put that into one documentation file. [ I have mangled this patch including comments from several grammar improvements proposed by Neal Murphy <neal.p.murphy@alum.wpi.edu>, any new grammar error is my mistake --pablo ] Signed-off-by: Jiri Pirko <jiri@resnulli.us> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2013-01-18 03:05:08 +04:00
nf_conntrack_tcp_be_liberal - BOOLEAN
0 - disabled (default)
not 0 - enabled
Be conservative in what you do, be liberal in what you accept from others.
If it's non-zero, we mark only out of window RST segments as INVALID.
nf_conntrack_tcp_loose - BOOLEAN
0 - disabled
not 0 - enabled (default)
If it is set to zero, we disable picking up already established
connections.
nf_conntrack_tcp_max_retrans - INTEGER
default 3
Maximum number of packets that can be retransmitted without
received an (acceptable) ACK from the destination. If this number
is reached, a shorter timer will be started.
nf_conntrack_tcp_timeout_close - INTEGER (seconds)
default 10
nf_conntrack_tcp_timeout_close_wait - INTEGER (seconds)
default 60
nf_conntrack_tcp_timeout_established - INTEGER (seconds)
default 432000 (5 days)
nf_conntrack_tcp_timeout_fin_wait - INTEGER (seconds)
default 120
nf_conntrack_tcp_timeout_last_ack - INTEGER (seconds)
default 30
nf_conntrack_tcp_timeout_max_retrans - INTEGER (seconds)
default 300
nf_conntrack_tcp_timeout_syn_recv - INTEGER (seconds)
default 60
nf_conntrack_tcp_timeout_syn_sent - INTEGER (seconds)
default 120
nf_conntrack_tcp_timeout_time_wait - INTEGER (seconds)
default 120
nf_conntrack_tcp_timeout_unacknowledged - INTEGER (seconds)
default 300
nf_conntrack_timestamp - BOOLEAN
0 - disabled (default)
not 0 - enabled
Enable connection tracking flow timestamping.
nf_conntrack_udp_timeout - INTEGER (seconds)
default 30
nf_conntrack_udp_timeout_stream2 - INTEGER (seconds)
default 180
This extended timeout will be used in case there is an UDP stream
detected.
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