From: Chia-Yu Chang chia-yu.chang@nokia-bell-labs.com
Enable Accurate ECN negotiation and request for incoming and outgoing connection by setting sysctl_tcp_ecn:
+==============+===========================================+ | | Highest ECN variant (Accurate ECN, ECN, | | tcp_ecn | or no ECN) to be negotiated & requested | | +---------------------+---------------------+ | | Incoming connection | Outgoing connection | +==============+=====================+=====================+ | 0 | No ECN | No ECN | | 1 | ECN | ECN | | 2 | ECN | No ECN | +--------------+---------------------+---------------------+ | 3 | Accurate ECN | Accurate ECN | | 4 | Accurate ECN | ECN | | 5 | Accurate ECN | No ECN | +==============+=====================+=====================+
Refer Documentation/networking/ip-sysctl.rst for more details.
Signed-off-by: Chia-Yu Chang chia-yu.chang@nokia-bell-labs.com --- net/ipv4/sysctl_net_ipv4.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c index 91a90c34a810..9072584e6617 100644 --- a/net/ipv4/sysctl_net_ipv4.c +++ b/net/ipv4/sysctl_net_ipv4.c @@ -47,7 +47,7 @@ static unsigned int udp_child_hash_entries_max = UDP_HTABLE_SIZE_MAX; static int tcp_plb_max_rounds = 31; static int tcp_plb_max_cong_thresh = 256; static unsigned int tcp_tw_reuse_delay_max = TCP_PAWS_MSL * MSEC_PER_SEC; -static int tcp_ecn_mode_max = 2; +static int tcp_ecn_mode_max = 5;
/* obsolete */ static int sysctl_tcp_low_latency __read_mostly;