{"id":1632,"date":"2010-06-06T22:40:19","date_gmt":"2010-06-06T17:10:19","guid":{"rendered":"http:\/\/www.jeffrin.in\/?p=1632"},"modified":"2010-06-06T22:40:19","modified_gmt":"2010-06-06T17:10:19","slug":"number-of-unacknowledged-probes-tcp","status":"publish","type":"post","link":"https:\/\/www.trueangle.org\/index.php\/2010\/06\/06\/number-of-unacknowledged-probes-tcp\/","title":{"rendered":"number of unacknowledged probes TCP"},"content":{"rendered":"<pre>\ntcp_keepalive_probes\n\nthe number of unacknowledged probes to send before considering the connection\ndead and notifying the application layer\n\nsource : www.tldp.org\n<\/pre>\n<pre>\n$cat \/proc\/sys\/net\/ipv4\/tcp_keepalive_probes\n9\n$\n<\/pre>\n<pre>\n\ntrunk\/os\/ip\/tcp.c - 7 identical\n  2436:   \/* Compute usable segment based on offered window and limit\n  2437:    * window probes to one\n  2438:    *\/\n  3064:           return tcphangup(c);\n  3065:   if(n &gt;= 1 &amp;&amp; strcmp(f[0], \"keepalive\") == 0)\n  3066:           return tcpstartka(c, f, n);\ninferno-os.googlecode.com\/svn - MIT - C\n<\/pre>\n<pre>\n\nTaken from Research Paper.\n\nTCP Keep-alives\n\nThe TCP speci?cation does not include a mecha-\nnism for probing idle connections. In theory, if a host\ncrashes after establishing a connection to another host,\nthe second machine will continue to hold the idle con-\nnection forever. Some TCP implementations include a\nmechanism that tests an idle connection and releases it\nif the remote host has crashed. Called TCP keep-alive,\nthe mechanism periodically sends a probe segment to\nelicit response from the peer. If the peer responds to\nthe probe by sending an ACK, the connection is alive.\nIf the peer TCP fails to respond to probe segments for\nlonger than a ?xed threshold,the connection is declared\ndown and the connection is closed.\n\n<a href=\"http:\/\/www.jeffrin.in\/wp-content\/uploads\/2010\/06\/10.1.1.24.7007.pdf\">Probing TCP Implementations\n<\/a>\n<\/pre>\n","protected":false},"excerpt":{"rendered":"<p>tcp_keepalive_probes the number of unacknowledged probes to send before considering the connection dead and notifying the application layer source : www.tldp.org $cat \/proc\/sys\/net\/ipv4\/tcp_keepalive_probes 9 $ trunk\/os\/ip\/tcp.c &#8211; 7 identical 2436: \/* Compute usable segment based on offered window and limit 2437: * window probes to one 2438: *\/ 3064: return tcphangup(c); 3065: if(n &gt;= 1 &hellip; <\/p>\n<p class=\"link-more\"><a href=\"https:\/\/www.trueangle.org\/index.php\/2010\/06\/06\/number-of-unacknowledged-probes-tcp\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;number of unacknowledged probes TCP&#8221;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[19],"tags":[1057],"_links":{"self":[{"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/posts\/1632"}],"collection":[{"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/comments?post=1632"}],"version-history":[{"count":0,"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/posts\/1632\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/media?parent=1632"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/categories?post=1632"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/tags?post=1632"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}