From c21ccc08b8a2ae4fdf328085be87c0b69ef74180 Mon Sep 17 00:00:00 2001 From: K4YT3X Date: Tue, 12 Oct 2021 17:17:31 +0000 Subject: [PATCH] updated comments for MTU probing references: https://blog.cloudflare.com/ip-fragmentation-is-broken/ --- sysctl.conf | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) diff --git a/sysctl.conf b/sysctl.conf index 8cdfcee..3e7e5bb 100644 --- a/sysctl.conf +++ b/sysctl.conf @@ -215,14 +215,6 @@ net.ipv4.ip_local_port_range = 1024 65535 # - 2: enable timestamps without random offsets net.ipv4.tcp_timestamps = 0 -# SSR could impact TCP's performance on a fixed-speed network (e.g., wired) -# but it could be helpful on a variable-speed network (e.g., LTE) -# uncomment this if you are on a fixed-speed network -#net.ipv4.tcp_slow_start_after_idle = 0 - -# useful if there are ICMP blackholes between you and your clients (most likely there are). -net.ipv4.tcp_mtu_probing=1 - # enabling SACK can increase the throughput # but SACK is commonly exploited and rarely used net.ipv4.tcp_sack = 0 @@ -230,6 +222,15 @@ net.ipv4.tcp_sack = 0 # divide socket buffer evenly between TCP window size and application net.ipv4.tcp_adv_win_scale = 1 +# SSR could impact TCP's performance on a fixed-speed network (e.g., wired) +# but it could be helpful on a variable-speed network (e.g., LTE) +# uncomment this if you are on a fixed-speed network +#net.ipv4.tcp_slow_start_after_idle = 0 + +# enabling MTU probing helps mitigating PMTU blackhole issues +# this may not be desirable on congested networks +#net.ipv4.tcp_mtu_probing = 1 + # increase memory thresholds to prevent packet dropping #net.ipv4.tcp_rmem = 4096 87380 8388608 #net.ipv4.tcp_wmem = 4096 87380 8388608