1// Test client behavior on receiving a non ECN SYN-ACK 2// after receiving an AccECN SYN-ACK and moving to 3// ESTABLISHED state 4 5`./defaults.sh 6sysctl -q net.ipv4.tcp_ecn=3 7sysctl -q net.ipv4.tcp_ecn_option=2 8` 9 10 0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 4 11+.002 ... 0.052 connect(4, ..., ...) = 0 12 13+.002 > [noecn] SEWA 0:0(0) <mss 1460,sackOK,TS val 100 ecr 0,nop,wscale 8> 14// Receive an AccECN SYN-ACK and move to ESTABLISHED 15+0.05 < [noecn] SW. 0:0(0) ack 1 win 32767 <mss 1460,ECN e0b 1 ceb 0 e1b 1,nop,nop,nop,sackOK,nop,wscale 8> 16+.002 > [ect0] W. 1:1(0) ack 1 <ECN e1b 1 ceb 0 e0b 1,nop> 17 18// Receive a non ECN SYN-ACK and send a challenge ACK with ACE feedback 19+0.1 < [noecn] S. 0:0(0) ack 1 win 32767 <mss 1460,nop,nop,sackOK,nop,wscale 8> 20+.002 > [ect0] W. 1:1(0) ack 1 <ECN e1b 1 ceb 0 e0b 1,nop> 21