April 15, 2015

Chapter 6 - changes persisting after reboot


I got to the Chapter 6 Learning Objectives Review where it says I should understand how to make startup options and runtime options persist across system reboots. There are some external and man page references given about startup options and nothing explicit given about runtime options persisting after system reboot. There is not sufficient information in the course text and exercises to understand how to make configuration changes persist after reboot.

I found the following exercise useful for understanding runtime options persisting after reboot:

737 ping $HOSTNAME
738 #
739 # Edit /etc/sysctl.conf
740 # Insert "net.ipv4.icmp_echo_ignore_all=1" on the first line
741 sudo vim /etc/sysctl.conf
742 ping $HOSTNAME
743 sudo sysctl -p
744 ping $HOSTNAME
746 sudo shutdown now -r
747 ping $HOSTNAME
748 #
749 # Delete line added to /etc/sysctl.conf
750 sudo vim /etc/sysctl.conf
751 sysctl -p
752 ping $HOSTNAME
753 # Add line to /etc/sysctl.conf
754 # net.ipv4.icmp_echo_ignore_all=0
755 sudo vim /etc/sysctl.conf
757 sudo sysctl -p
758 ping $HOSTNAME
759 #
760 # Remove line added to /etc/sysctl.conf to restore
761 # pre-exercise state
762 sudo vim /etc/sysctl.conf

I have yet to work up courage to try out bootup options...

Click Here!