// // Copyright (c) 2022 Michael Tuexen // All rights reserved. // // Redistribution and use in source and binary forms, with or without // modification, are permitted provided that the following conditions // are met: // 1. Redistributions of source code must retain the above copyright // notice, this list of conditions and the following disclaimer. // 2. Redistributions in binary form must reproduce the above copyright // notice, this list of conditions and the following disclaimer in the // documentation and/or other materials provided with the distribution. // // THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND // ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE // ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE // FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL // DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS // OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) // HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT // LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY // OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF // SUCH DAMAGE. // --mtu=1500 --ip_version=ipv6 --tolerance_usecs=50000 // Ensure that all relevant sysctl variables have their default variables. 0.000 `sysctl -w net.inet.tcp.rfc1323=1` +0.000 `sysctl -w net.inet.tcp.sack.enable=1` +0.000 `sysctl -w net.inet.tcp.ecn.enable=2` +0.000 `sysctl -w net.inet.tcp.rexmit_slop=200` +0.000 `sysctl -w net.inet.tcp.rexmit_drop_options=0` +0.000 `sysctl -w kern.ipc.maxsockbuf=2097152` +0.000 `sysctl -w net.inet.tcp.recvspace=65536` +0.000 `sysctl -w net.inet.tcp.sendspace=32768` // Flush host cache. +0.000 `sysctl -w net.inet.tcp.hostcache.purgenow=1` // Create a TCP endpoint in the ESTABLISHED state. +0.000 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 +0.000 fcntl(3, F_GETFL) = 0x02 (flags O_RDWR) +0.000 fcntl(3, F_SETFL, O_RDWR | O_NONBLOCK) = 0 +0.000 connect(3, ..., ...) = -1 EINPROGRESS (Operation now in progress) +0.000 > S 0:0(0) win 65535 +0.100 < S. 0:0(0) ack 1 win 32767 +0.000 > . 1:1(0) ack 1 win 65535 +0.000 send(3, ..., 1440, 0) = 1440 +0.000 > P. 1:1441(1440) ack 1 win 65535 +0.100 < icmp packet_too_big mtu 1400 [1462:1462(0)] // Since the ICMP message is ignored, we have a timer based retransmission // after 3 RTT + rexmit_slop, which results in 500 ms. +0.400 > P. 1:1441(1440) ack 1 win 65535 // Tear it down. +0.000 close(3) = 0 +0.000 > F. 1441:1441(0) ack 1 win 65535 +0.100 < F. 1:1(0) ack 1442 win 32767 +0.000 > . 1442:1442(0) ack 2 win 65535 // Checked cached entry +0.000 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 +0.000 fcntl(3, F_GETFL) = 0x02 (flags O_RDWR) +0.000 fcntl(3, F_SETFL, O_RDWR | O_NONBLOCK) = 0 +0.000 connect(3, ..., ...) = -1 EINPROGRESS (Operation now in progress) +0.000 > S 0:0(0) win 65535 +0.000 close(3) = 0