$cat /proc/sys/net/ipv4/tcp_low_latency 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 …
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the interval between the last data packet sent and…
$cat /proc/sys/net/ipv4/tcp_keepalive_time 7200 $ tcp_keepalive_time the interval between the last data packet sent (simple ACKs are not considered data) and the first keepalive probe; after the connection is marked to need keepalive, this counter is not used any further source :http://tldp.org/HOWTO/TCP-Keepalive-HOWTO/usingkeepalive.html linux/net/ipv4/tcp.c – 8 identical 365: * TCP Keep-Alives (4.2.3.6) 366: * MAY provide keep-alives. …
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grep … -x .. exact line match only
$cat example.txt A for Apple. B for Baby. C for Cat. D for Donkey. $grep A example.txt A for Apple. $grep -x A example.txt $grep -x A for Apple. example.txt grep: for: No such file or directory grep: Apple.: No such file or directory $grep -x “A for Apple.” example.txt A for Apple. $grep -x …
tcp keepalive interval
$cat /proc/sys/net/ipv4/tcp_keepalive_intvl 75 $ tcp_keepalive_intvl the interval between subsequential keepalive probes, regardless of what the connection has exchanged in the meantime linux/net/ipv4/tcp.c – 8 identical 368: * MUST default to no keep-alives. (does) 369: * MUST make keep-alive interval configurable. (does) 370: * MUST make default keep-alive interval > 2 hours. (does) tcp_timer.c – 3 …
F-RTO response
$cat /proc/sys/net/ipv4/tcp_frto_response 0 $ 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 …
grep … -w matches that form whole words
grep -w :: selects only those lines containing matches that form whole words. $ cat samsung id proof license copy check leaf 1 $ $ grep -w lic samsung $ grep -w license samsung license copy $
F-RTO : an enhanced recovery algorithm for tcp retransmission timeouts
http://www.jeffrin.in/wp-content/uploads/2010/05/frto-ccr.pdf
Forward RTO-Recovery (F-RTO) defined in RFC4138
$cat /proc/sys/net/ipv4/tcp_frto 2 $ Enables Forward RTO-Recovery (F-RTO) defined in RFC4138. F-RTO is 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. F-RTO is sender-side only modification. Therefore it does not require any support …
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grep … no matching data -I
$grep -r deactivates * grep: trash4: No such file or directory grep: warning: X11/X11: recursive directory loop Binary file X11/zile matches grep: X11/trash4: No such file or directory Binary file zile matches $grep -I -r deactivates * grep: trash4: No such file or directory grep: warning: X11/X11: recursive directory loop grep: X11/trash4: No such file …
how long to keep sockets in the state FIN-WAIT-2
$cat /proc/sys/net/ipv4/tcp_fin_timeout 60 $ The tcp_fin_timeout variable tells kernel how long to keep sockets in the state FIN-WAIT-2 if you were the one closing the socket. This is used if the other peer is broken for some reason and don’t close its side, or the other peer may even crash unexpectedly. Each socket left in …
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