Hello, after observing mostly drops in cake (instead of marks) I did a little test:
Client is a Linux 5.9.13, server is the same. Kernel ECN parameters are set identically for both client and server to: net.ipv4.tcp_ecn = 1 net.ipv4.tcp_ecn_fallback = 1 Using tcpdump on the server I see the following: The client initiates the IPv4 TCP connection with: IP Differentiated Services Field: 0x02 (DSCP: CS0, ECN: ECT(0)) TCP Flags: 0x0c2 (SYN, ECN, CWR) Seq=0 Win=64240 Len=0 MSS=1460 WS=256 SACK_PERM=1 The server responds: Differentiated Services Field: 0x00 (DSCP: CS0, ECN: Not-ECT) Flags: 0x012 (SYN, ACK) Seq=0 Ack=1 Win=64240 Len=0 MSS=1460 SACK_PERM=1 WS=128 Shouldn't the server respond with ECT set in the SYN ACK packet and possibly also have ECN-related flags set in the TCP header? _______________________________________________ Cake mailing list [email protected] https://lists.bufferbloat.net/listinfo/cake
