diff options
Diffstat (limited to 'Documentation/networking/ip-sysctl.txt')
| -rw-r--r-- | Documentation/networking/ip-sysctl.txt | 66 |
1 files changed, 63 insertions, 3 deletions
diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index a0f6842368c3..af6a63ab9026 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -147,6 +147,11 @@ tcp_available_congestion_control - STRING More congestion control algorithms may be available as modules, but not loaded. +tcp_base_mss - INTEGER + The initial value of search_low to be used by Packetization Layer + Path MTU Discovery (MTU probing). If MTU probing is enabled, + this is the inital MSS used by the connection. + tcp_congestion_control - STRING Set the congestion control algorithm to be used for new connections. The algorithm "reno" is always available, but @@ -174,11 +179,31 @@ tcp_fin_timeout - INTEGER because they eat maximum 1.5K of memory, but they tend to live longer. Cf. tcp_max_orphans. -tcp_frto - BOOLEAN +tcp_frto - INTEGER 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. + rather than intermediate router congestion. If set to 1, basic + version is enabled. 2 enables SACK enhanced F-RTO, which is + EXPERIMENTAL. The basic version can be used also when SACK is + enabled for a flow through tcp_sack sysctl. + +tcp_frto_response - INTEGER + When F-RTO has detected that a TCP retransmission timeout was + spurious (i.e, the timeout would have been avoided had TCP set a + longer retransmission timeout), TCP has several options what to do + next. Possible values are: + 0 Rate halving based; a smooth and conservative response, + results in halved cwnd and ssthresh after one RTT + 1 Very conservative response; not recommended because even + though being valid, it interacts poorly with the rest of + Linux TCP, halves cwnd and ssthresh immediately + 2 Aggressive response; undoes congestion control measures + that are now known to be unnecessary (ignoring the + possibility of a lost retransmission that would require + TCP to be more cautious), cwnd and ssthresh are restored + to the values prior timeout + Default: 0 (rate halving based) tcp_keepalive_time - INTEGER How often TCP sends out keepalive messages when keepalive is enabled. @@ -243,6 +268,27 @@ tcp_mem - vector of 3 INTEGERs: min, pressure, max Defaults are calculated at boot time from amount of available memory. +tcp_moderate_rcvbuf - BOOLEAN + If set, TCP performs receive buffer autotuning, attempting to + automatically size the buffer (no greater than tcp_rmem[2]) to + match the size required by the path for full throughput. Enabled by + default. + +tcp_mtu_probing - INTEGER + Controls TCP Packetization-Layer Path MTU Discovery. Takes three + values: + 0 - Disabled + 1 - Disabled by default, enabled when an ICMP black hole detected + 2 - Always enabled, use initial MSS of tcp_base_mss. + +tcp_no_metrics_save - BOOLEAN + By default, TCP saves various connection metrics in the route cache + when the connection closes, so that connections established in the + near future can use these to set initial conditions. Usually, this + increases overall performance, but may sometimes cause performance + degredation. If set, TCP will not cache metrics on closing + connections. + tcp_orphan_retries - INTEGER How may times to retry before killing TCP connection, closed by our side. Default value 7 corresponds to ~50sec-16min @@ -825,6 +871,15 @@ accept_redirects - BOOLEAN Functional default: enabled if local forwarding is disabled. disabled if local forwarding is enabled. +accept_source_route - INTEGER + Accept source routing (routing extension header). + + > 0: Accept routing header. + = 0: Accept only routing header type 2. + < 0: Do not accept routing header. + + Default: 0 + autoconf - BOOLEAN Autoconfigure addresses using Prefix Information in Router Advertisements. @@ -960,7 +1015,12 @@ bridge-nf-call-ip6tables - BOOLEAN Default: 1 bridge-nf-filter-vlan-tagged - BOOLEAN - 1 : pass bridged vlan-tagged ARP/IP traffic to arptables/iptables. + 1 : pass bridged vlan-tagged ARP/IP/IPv6 traffic to {arp,ip,ip6}tables. + 0 : disable this. + Default: 1 + +bridge-nf-filter-pppoe-tagged - BOOLEAN + 1 : pass bridged pppoe-tagged IP/IPv6 traffic to {ip,ip6}tables. 0 : disable this. Default: 1 |