but do not request ECN on outgoing connections.
Default: 2
+tcp_ecn_fallback - BOOLEAN
+ If the kernel detects that ECN connection misbehaves, enable fall
+ back to non-ECN. Currently, this knob implements the fallback
+ from RFC3168, section 6.1.1.1., but we reserve that in future,
+ additional detection mechanisms could be implemented under this
+ knob. The value is not used, if tcp_ecn or per route (or congestion
+ control) ECN settings are disabled.
+ Default: 1 (fallback enabled)
+
tcp_fack - BOOLEAN
Enable FACK congestion avoidance and fast retransmission.
The value is not used, if tcp_sack is not enabled.
Defaults are calculated at boot time from amount of available
memory.
+tcp_min_rtt_wlen - INTEGER
+ The window length of the windowed min filter to track the minimum RTT.
+ A shorter window lets a flow more quickly pick up new (higher)
+ minimum RTT when it is moved to a longer path (e.g., due to traffic
+ engineering). A longer window makes the filter more resistant to RTT
+ inflations such as transient congestion. The unit is seconds.
+ Default: 300
+
tcp_moderate_rcvbuf - BOOLEAN
If set, TCP performs receive buffer auto-tuning, attempting to
automatically size the buffer (no greater than tcp_rmem[2]) to
you should think about lowering this value, such sockets
may consume significant resources. Cf. tcp_max_orphans.
+tcp_recovery - INTEGER
+ This value is a bitmap to enable various experimental loss recovery
+ features.
+
+ RACK: 0x1 enables the RACK loss detection for fast detection of lost
+ retransmissions and tail drops.
+
+ Default: 0x1
+
tcp_reordering - INTEGER
Initial reordering level of packets in a TCP stream.
TCP stack can then dynamically adjust flow reordering level
if available window is too small.
Default: 2
+tcp_pacing_ss_ratio - INTEGER
+ sk->sk_pacing_rate is set by TCP stack using a ratio applied
+ to current rate. (current_rate = cwnd * mss / srtt)
+ If TCP is in slow start, tcp_pacing_ss_ratio is applied
+ to let TCP probe for bigger speeds, assuming cwnd can be
+ doubled every other RTT.
+ Default: 200
+
+tcp_pacing_ca_ratio - INTEGER
+ sk->sk_pacing_rate is set by TCP stack using a ratio applied
+ to current rate. (current_rate = cwnd * mss / srtt)
+ If TCP is in congestion avoidance phase, tcp_pacing_ca_ratio
+ is applied to conservatively probe for bigger throughput.
+ Default: 120
+
tcp_tso_win_divisor - INTEGER
This allows control over what percentage of the congestion window
can be consumed by a single TSO frame.
typical pfifo_fast qdiscs.
tcp_limit_output_bytes limits the number of bytes on qdisc
or device to reduce artificial RTT/cwnd and reduce bufferbloat.
- Default: 131072
+ Default: 262144
tcp_challenge_ack_limit - INTEGER
Limits number of Challenge ACK sent per second, as recommended
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. The default values are
- 32768 and 61000 respectively.
+ second the last local port number.
+ If possible, it is better these numbers have different parity.
+ (one even and one odd values)
+ The default values are 32768 and 60999 respectively.
ip_local_reserved_ports - list of comma separated ranges
Specify the ports which are reserved for known third-party
ip_local_port_range, e.g.:
$ cat /proc/sys/net/ipv4/ip_local_port_range
- 32000 61000
+ 32000 60999
$ cat /proc/sys/net/ipv4/ip_local_reserved_ports
8080,9148
Allows you to write a number, which can be used as required.
Default value is 0.
+xfrm4_gc_thresh - INTEGER
+ The threshold at which we will start garbage collecting for IPv4
+ destination cache entries. At twice this value the system will
+ refuse new allocations. The value must be set below the flowcache
+ limit (4096 * number of online cpus) to take effect.
+
+igmp_link_local_mcast_reports - BOOLEAN
+ Enable IGMP reports for link local multicast groups in the
+ 224.0.0.X range.
+ Default TRUE
+
Alexey Kuznetsov.
kuznet@ms2.inr.ac.ru
FALSE: disabled
Default: TRUE
-auto_flowlabels - BOOLEAN
- Automatically generate flow labels based based on a flow hash
- of the packet. This allows intermediate devices, such as routers,
- to idenfify packet flows for mechanisms like Equal Cost Multipath
+auto_flowlabels - INTEGER
+ Automatically generate flow labels based on a flow hash of the
+ packet. This allows intermediate devices, such as routers, to
+ identify packet flows for mechanisms like Equal Cost Multipath
Routing (see RFC 6438).
+ 0: automatic flow labels are completely disabled
+ 1: automatic flow labels are enabled by default, they can be
+ disabled on a per socket basis using the IPV6_AUTOFLOWLABEL
+ socket option
+ 2: automatic flow labels are allowed, they may be enabled on a
+ per socket basis using the IPV6_AUTOFLOWLABEL socket option
+ 3: automatic flow labels are enabled and enforced, they cannot
+ be disabled by the socket option
+ Default: 1
+
+flowlabel_state_ranges - BOOLEAN
+ Split the flow label number space into two ranges. 0-0x7FFFF is
+ reserved for the IPv6 flow manager facility, 0x80000-0xFFFFF
+ is reserved for stateless flow labels as described in RFC6437.
TRUE: enabled
FALSE: disabled
- Default: false
+ Default: true
anycast_src_echo_reply - BOOLEAN
Controls the use of anycast addresses as source addresses for ICMPv6
disabled if accept_ra_from_local is disabled
on a specific interface.
+accept_ra_min_hop_limit - INTEGER
+ Minimum hop limit Information in Router Advertisement.
+
+ Hop limit Information in Router Advertisement less than this
+ variable shall be ignored.
+
+ Default: 1
+
accept_ra_pinfo - BOOLEAN
Learn Prefix Information in Router Advertisement.
Default Maximum Transfer Unit
Default: 1280 (IPv6 required minimum)
+ip_nonlocal_bind - BOOLEAN
+ If set, allows processes to bind() to non-local IPv6 addresses,
+ which can be quite useful - but may break some applications.
+ Default: 0
+
router_probe_interval - INTEGER
Minimum interval (in seconds) between Router Probing described
in RFC4191.
routers are present.
Default: 3
+use_oif_addrs_only - BOOLEAN
+ When enabled, the candidate source addresses for destinations
+ routed via this interface are restricted to the set of addresses
+ configured on this interface (vis. RFC 6724, section 4).
+
+ Default: false
+
use_tempaddr - INTEGER
Preference for Privacy Extensions (RFC3041).
<= 0 : disable Privacy Extensions
otherwise the minimal space between responses in milliseconds.
Default: 1000
+xfrm6_gc_thresh - INTEGER
+ The threshold at which we will start garbage collecting for IPv6
+ destination cache entries. At twice this value the system will
+ refuse new allocations. The value must be set below the flowcache
+ limit (4096 * number of online cpus) to take effect.
+
IPv6 Update by:
Pekka Savola <pekkas@netcore.fi>
Code Review / kvmfornfv.git / blobdiff