tcp_keepalive_time: Operation not permitted
 

[apache2]# echo 300 > /proc/sys/net/ipv4/tcp_keepalive_time
-bash: /proc/sys/net/ipv4/tcp_keepalive_time: Operation not permitted

Use the sysctl command:

sysctl net.ipv4.tcp_keepalive_time=300

Type "man sysctl" for more information.

Don't forget to update /etc/sysctl.conf if you want to have this change survive a reboot.

Why doesn't echo 300 > /proc/sys/net/ipv4/tcp_keepalive_time work ?

Echoing stuff to proc may or may not work depending on distribution and permissions (and maybe SELinux and AppArmor, if you have one of those available, to make your life more interesting).

Were you root when you tried this?

Yes I am root. How can I give permissions?

What's your distro (with version)?

What's your kernel version?

What does "who am i" and "whoami" show you as when you try this?

Are you running SELinux as prior poster asked?

What's the permissions on /proc/sys/net/ipv4/tcp_keepalive_time?

Why don't you want to use sysctl?