In Linux , It's a security concern for us to allow anyone to **reboot** the server using **Ctrl-Alt-Del keys**. It is always recommended in production boxes that one should disable reboot uisng Ctrl-Alt-Del keys.
In this article we will discuss how can we disable reboot via above keys in RHEL & CentOS
### For RHEL 5.X & CentOS 5.X ###
To prevent the **init** process from handling **Ctrl-Alt-Del**, edit the file '**/etc/inittab**' comment the line which begins with '**ca::ctrlaltdel**:' as shown below :
[root@localhost ~]# cat /etc/inittab
# Trap CTRL-ALT-DELETE
#ca::ctrlaltdel:/sbin/shutdown -t3 -r now
We can also modify the line 'ca::ctrlaltdel:' to generate logs , if anybody try to reboot the server using the keys ,
[root@localhost ~]# cat /etc/inittab
# Trap CTRL-ALT-DELETE
ca::ctrlaltdel:/bin/logger -p authpriv.warning -t init "Console-invoked Ctrl-Alt-Del was ignored"
### For RHEL6.X & CentOS 6.X ###
In RHEL 6.X / CentOS 6.X , reboot using the keys are handled by the file '**/etc/init/control-alt-delete.conf**'.
**Step:1** Before making the changes , first take the backup using below command
**Step:2** Edit the file , replacing the 'exec /sbin/shutdown' line with the following, which will simply generate a log entry each time Ctrl-Alt-Del is pressed:
