RHCE EX300 Exam Preparation on RHEL 7 – getting your hands on firewall-cmd

RHEL 7 uses firewall-cmd for managing firewall rules, before you practice iptables should be disabled and stopped on your RHEL 7 servers.

1.using systemctl to stop the iptables :

#systemctl mask iptables ip6tables


2. how to verify what zones are enabled and what port/services are running ?

#sudo firewall-cmd --get-default-zone
public


3.List the ports and services

#sudo firewall-cmd --permanent --zone=public --list-all
public (default)
interfaces:
sources:
services: dhcpv6-client ssh
ports:
masquerade: no
forward-ports:
icmp-blocks:
rich rules:


 

4.Practice adding port 443 to your public zone using firewall-cmd


#firewall-cmd --permanent --zone=public --add-port 443/tcp


This book is an excellent resource for preparing for  RHCE exam, this book cover more practice questions I used for passing my RHCE exam, there is also a DVD included which you can take with you to learn topics like firewalld.

EX300 RHCE Exam Practice Questions systemctl

How to Practice for RHCE EX300 Exam for RHEL 7

• Service commands in RHEL 7 has been replaced by systemctl, for passing RHCE exam you should know how to
  • enable/disable the services
  • restart the services.


[marvin@server10 ~]$ sudo systemctl enable sshd
[marvin@server10 ~]$ sudo systemctl is-enabled sshd
[marvin@server10 ~]$ sudo systemctl status sshd


[marvin@server10 ~]$ sudo systemctl disable sshd
[marvin@server10 ~]$ sudo systemctl is-enabled sshd
[marvin@server10 ~]$ sudo systemctl status sshd

If you want to prepare for RHCE exam (EX300) with desire to pass the exam then you must buy this excellent book , geared and designed to make you full trained to work on RHEL 7 servers.

EX300 RHCE Exam Practice Questions install httpd

Question : How will you Install the http services and then make the webserver start automatically when server reboots ?

Step 1. Install the http server using yum command


[student@server10 ~]$ sudo yum -y install


Step 2.Create the /var/www/html/index.html file with a text editor as user root, and add the content “hello World!”:

Step 3.Start and enable the http services:

[student@server10 ~]$ sudo systemctl start httpd.service
[student@server10 ~]$ sudo systemctl enable httpd.service


Step 4.Make sure all the relevant ports for http on the firewall on your server.

[student@server10 ~]$ sudo firewall-cmd –permanent –add-service=http
[student@server10 ~]$ sudo firewall-cmd –reload

if you want to Practice more EX300 Exam Questions and learn about firewall-cmd then try out this new book for increasing your chances to pass the RHCE exam for RHEL 7

• Learn Red Hat Certified Engineer – Exam EX300 Training from a professional trainer from your own desk.
• Visual training method, offering users increased retention and accelerated learning
• Breaks even the most complex applications down into simplistic steps.
• Easy to follow step-by-step lessons, ideal for all

RHCSA for RHEL 7 Exam Questions you should know

RHEL 7 includes lots of new changes, one of the change is how to set the hostname for RHEL 7 Linux servers and configuration files involved in hostname change process.

In order to pass the RHCSA Exam you must practice on CentOS 7 or Red hat Enterprise Linux 7 Servers how to change hostname

1. How to find Hostname in RHEL

#hostnamectl

Static hostname: rhel7.example.com
Icon name: computer-laptop
Chassis: laptop
Machine ID: bcdc71f1943f4d859aa37e54a422938d
Boot ID: f84556924b4e4bbf9c4a82fef4ac26d0
Operating System: Red Hat Enterprise Linux Everything 7.0 (Maipo)
CPE OS Name: cpe:/o:redhat:enterprise_linux:7.0:beta:everything
Kernel: Linux 3.10.0-54.0.1.el7.x86_64
Architecture: x86_64

To change the  the rhel7 hostname permanently to the server, type:

# hostnamectl set-hostname rhel7server10

Red Hat RHCE/RHCSA Certification on Red Hat Enterprise Linux 7

What to expect in RHCE/RHCSA (EX200 and EX300) : – You need hands on practice on RHEL 7 servers , specially firewall-cmd commands and systemctl to manage the run levels.

• RHCE RHEL 7 exam includes questions on using   network teaming or bonding to configure aggregated network links between two Red Hat Enterprise Linux systems.
• Configure IPv6 addresses and perform basic IPv6 troubleshooting, setting up Route IP traffic and create static routes.
• Use firewalld and associated mechanisms such as rich rules, zones and custom rules, to implement packet filtering and configure network address translation (NAT).
• Use /proc/sys and sysctl to modify and set kernel runtime parameters.
• Configure a system to authenticate using Kerberos.
• Configure a system as either an iSCSI target or initiator that persistently mounts an iSCSI target.
• Produce and deliver reports on system utilization (processor, memory, disk, and network).
• Use shell scripting to automate system maintenance tasks.

I passed the exam after reading this Book , this Certification book covers EX200 and EX300 topics very well, I highly recommend this book by  Sander Van :