On Fri, 2017-01-13 at 12:32 -0500, Neal Cardwell wrote: > On Fri, Jan 13, 2017 at 12:14 PM, Eric Dumazet <eduma...@google.com> wrote: > > > > On Fri, Jan 13, 2017 at 9:07 AM, Alexey Kodanev > > <alexey.koda...@oracle.com> wrote: > > > Hi Eric, > > > On 13.01.2017 18:35, Eric Dumazet wrote: > > > > >> Care to send a packetdrill test so that we have a clear picture of what > > >> is going on ? > > > > > > Is it capable of making two connections in the single test, one after > > > another? > > > > Absolutely. > > > > Neal, Yuchung would you be kind enough to send a Fastopen tpacketdrill > > template showing a typical fastopen test > > running on an upstream kernel ? > > > > Thanks ! > > Sure, here is an example packetdrill script, IIRC written by Yuchung, > which demonstrates TCP fast open and consecutive active connections: > > `sysctl -q net.ipv4.tcp_timestamps=0` > > // Cache warmup: send a Fast Open cookie request > 0.000 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 > +0 fcntl(3, F_SETFL, O_RDWR|O_NONBLOCK) = 0 > +0 sendto(3, ..., 0, MSG_FASTOPEN, ..., ...) = -1 EINPROGRESS > (Operation is now in progress) > +0 > S 0:0(0) <mss 1460,nop,nop,sackOK,nop,wscale 8,FO,nop,nop> > +.010 < S. 123:123(0) ack 1 win 5840 <mss > 1040,nop,nop,sackOK,nop,wscale 6,FO abcd1234,nop,nop> > +0 > . 1:1(0) ack 1 > +0 close(3) = 0 > +0 > F. 1:1(0) ack 1 > +.010 < F. 1:1(0) ack 2 win 92 > +0 > . 2:2(0) ack 2 > > // > // TEST1: Servers sends SYN-ACK with data and another two data packets > // > +0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 4 > +0 fcntl(4, F_SETFL, O_RDWR|O_NONBLOCK) = 0 > +0 sendto(4, ..., 1000, MSG_FASTOPEN, ..., ...) = 1000 > +0 > S 0:1000(1000) <mss 1460,nop,nop,sackOK,nop,wscale 8,FO > abcd1234,nop,nop> > +.010 < S. 1000000:1001400(1400) ack 1001 win 5840 <mss > 1040,nop,nop,sackOK,nop,wscale 6> > +0 < . 1401:2801(1400) ack 1001 win 257 > +0 < P. 2801:3001(200) ack 1001 win 257 > > neal
Thanks Neal Also worth adding that packetdrill has the following option to tune the MTU on the tun device : --mtu=xxxxx
