Setting keep alive for unix

We have to change the value shown by:
>cat /proc/sys/net/ipv4/tcp_keepalive_time

-usually is 7200

To change it:
- >sudo vi /etc/rc.local #to remain after boot
- echo "900" > /proc/sys/net/ipv4/tcp_keepalive_time #to modify
- >sudo /etc/rc.local #to have it

Other way:
- >sudo sysctl -w net.ipv4.tcp_keepalive_time=1800