AWS net.ipv4.tcp_tw_recycle follow-up

Yesterday I wrote a post on AWS EC2 instance networking problem that I was pretty surprised to find out. And while yesterday I was focusing on fixing the problem, today my first task was to find out what actually sets the flag, and quick grep on /etc of the instance revealed that the settings were applied by /etc/sysctl.d/net.ipv4.tcp_tw_recycle.

Very strange to find it there along with net.ipv4.tcp_tw_reuse¬†which is also something that you should not touch. Anyhow, the problem identified, fixed and is about to be added to monitoring…

Leave a Reply