RHCE RHCT EXAM: configure kernel parameters in redhat enterprise Linux

configure kernel parameters in redhat enterprise Linux :

How to turn off ping response in redhat Linux :

#cat /proc/sys/net/ipv4/icmp_echo_ignore_all
0

Zero means ping is enable and Linux machine will respond to ping requests.

# echo "1" > /proc/sys/net/ipv4/icmp_echo_ignore_all

This kernel change is not permanent , to make it permanent add to /etc/sysctl.conf :

net.ipv4.icmp_echo_ignore_all=1

RHCE RHCT Exam questions : enable telnet services on Linux

How to enable telnet services on Redhat enterprise Linux :

# chkconfig telnet --list
#chkconfig telnet on
#chkconfig --level 35 telnet on

where 3 and 5 are run levels , so telnet will run when Linux is running in runlevel 3 and 5 only.

RHCE RHCT Exam questions : How to change Linux default run level

You shoud know how to change Redhat Linux system default run level for RHCE and RHCT exam preparation and questions :

1. edit /etc/inittab file and changerun level from level 5 (which is X or GUI mode ) to run level 3


# vi /etc/inittab
id:3:initdefault:

2. simply reboot the server and your default run level changes to level 3 which is text based linux session.

3.How to dynamically change the runlevel of Linux system without rebooting

• e.g: switch to single user mode :

# telinit S

• e.g: switch to X or GUI (desktop) mode

#telinit 5

• e.g:If you have made changes to the /etc/inittab file to change the default runlevel and want to change the system to that new default you can do so by using the telinit with the q command-line option:

# telinit q

RHCE RHCT EXAM: Pass exam

About Passing RHCT and RHCE exam , both exams are Pass or non-Pass. Redhat Send results for pass or did not pass within 3 Business days.

How do you receive your RHCT/RHCE Certificate:

If you pass your RHCT and RHCE exams , you will receive certificate in form of PDF emailed to you.Redhat doesn't mail RHCT and RHCE certificate bia regular mail.