Linux Permissions and User Management

The assignment focuses on configuring file permissions within a Linux environment. It involves creating a user account, navigating the file system, checking existing permissions using the 'ls -ltr' command, and modifying permissions on a specific directory ('test_dir') to ensure that the owner has full read/write access while others can only list its contents. The assignment utilizes commands like 'chmod' and provides a brief explanation of permission concepts.

PART-2 : 1 DNS Server Preparation
References : (Guide, 2017) (Tutorials For Kyup.com, 2017)
Prepared DNS Server (Tutorials For Kyup.com, 2017)
User name is user and hostname is Ubuntu.
Changed hostname to perera.itc514.edu
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Logged off and logged in to the new host name
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Added user name assgn2
References : (Lifewire, 2017)
Added assgn2 to sudoers group
References : (Digitalocean.com, 2017)
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Installed DNS Server
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DNS utilities and BIND DOCS Installation
sudo apt-get install dnsutils bind9-doc
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Primary master
Took Back up of the present DNS records and the domain details. New Domain Name: itc514.edu
FQDN of the server perera.itc514.edu
FQDN of the Client pereraclient.itc514.edu
DNS Server IP: 192.168.10.1
Checked and verified that the server is ready for creating two zone files. Forward lookup zone
and Reverse Lookup zone.
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Forward Lookup Zone
zone " itc514.edu" {
type master;
file "/etc./bind/db.itc514.edu";
};
Reverse zone file
zone "10.168.192.in-addr.arpa" {
type master;
notify no;
file "/etc/bind/db.192";
};
Restarted the service.
sudo service bind9 restart
MAJOR TASK
Referrence
Created domain in itc514.edu.local file
#vi /etc/bind/itc514.edu.local
//Forward zone
Zone “perera.itc514.edu”{
type master;
file “/etc/bind/itc514.edu.local
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//reverse zone
zone “10.168.192.in-addr.arpa”{
type master;
file “/etc/bind/db.10”;
};
Made forward and reverse entries as asked
# vi /etc/bind/db.itc514.edu
# vi /etc/bind/db.1
DNS Server Testing
#nsloookup 192.168.10.5
host1
#nslookup host1
192.168.10.5
#nsloookup 192.168.10.6
Host2
#nslookup host3
192.168.10.7
#nslookup host1
192.168.10.5
#nslookup host2
192.168.10.6
#nslookup host3
192.168.10.7
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Problems faced in Linux based DNS servers
Linux server rebooted 5 times in this practical
Could not install linux images easily.
Downloading linux images is not easy.
Lot of families and their commands are difficult to understand.
Got good support documents but understanding the documents is not easy
Changed hostname using hostname command and added user id using usedadd command. These
are all not standard ways to do these tasks.
a. The Linux OS (Operating System) is free to use through more number of users.
b. It does not have rules and limitation for using it.
c. The cost is less for the operators to own an OS that cost is nothing.
d. The cost is zero there is a general disadvantage which affects the user of the Linux
operating system.
e. The firm must hire a well knowledgeable candidate who has the knowledge of using the
Linux commands
f. This is due to time-consuming task to study everything about the working of a Linux
system.
g. The users of Linux system will not feel troubled for the Linux system to get crack as in
Linux system.
h. It is one of the operative and valuable facility that the system hardly gets crashed and it
faces system crash, it is ensured that the Linux system will not reduce its performance.
i. Every firm wants security as a primary feature for Linux operating systems, that provides
Linux operating system.
There are common problem of installation freezing, and once the user encounters this it is must
to ensure the following steps:
1. Initially, wait for some time and check whether the installation has really freezed or not.
2. Certain times, this problem can be resolved with computer rebooting, which can completely
resolve this issue.
3. In case, if the problem persists more than twice consistently, then try rebooting for more
number of times as it can resolve this issue.
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4. If the problem continues and freezes at the same place, in such case move on to the support
pages of the distribution. Because, it could contain the solution from the existing discussion.
If the above steps doesn't fix the freezing issue, then the following tips will be handy to avoid the
freezing of this process:
a) The repeated freezing at the same place can be the result of bad installation disk.
Give it a try in other system to check whether the installation continues similarly
b) If you don’t encounter the same pace freezing issue, the issue can be in the computer’s
hardware components.
c) If not there might be issue with compatible system.
Mistakes happened while working with linux.
Mounting from source
There are many Linux users who did not understand rpm and apt. It has path of everything installed
on the system. In its place, create either an .rpm or .deb file from the source and install the package.
Ignoring graphical front-end package
People will never understand graphical front end. So it is asked to use Yumex for yum and can use
Synaptic or Adept for apt.
Disremembering to update
When using apt-get or yum, ensure for updating the set of offered packages or system will not
persist updating.
No sources for yum or apt-get
The command to install an application, and yum (or apt-get) and the package can’t be find.
No benefit of mounting
It is tough to install it directly and so it is asked to use the browser.
PART-2 : 2
References :
2) Create a user "assgn2' and in their home directory create the files with the following permission
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Already added the user assgn2 and added that user to sudo group too
assgn2@perera : /home/reddy# touch processes.txt
assgn2@perera: /home/reddy# cat > processes.txt
ps aux |less
assgn2@perera: /home/assgn2# ls –l processes.txt
-rw-r—r-- 1 root root 3049 2017-08-24 02:50 processes.txt
assgn2@perera: /home/assgn2# chmod g+w processes.txt
assgn2@perera: /home/assgn2# chmod o+w processes.txt
assgn2@perera: /home/assgn2# ls –l processes.txt
-rw-rw-rw- 1 root root 3049 2017-08-27 04:40 processes.txt
script1.sh file creation
assgn2@perera:$ touch script1.sh
assgn2@perera:$ cat >script1.sh
#!/bin/bash
chmod -R 760 .
mypath=`realpath $0`
cd `dirname $mypath`
pwd
b) Answer –
assgn2@perera: /home/assgn2# chmod g+rx script1.sh
assgn2@perera: /home/assgn2# chmod o+rx script1.sh
assgn2@perera: /home/assgn2# chmod u+x script1.sh
used the following commands
touch .test_config
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ls –l .test_config
chmod u+x .test_config
References : (Kb.iu.edu, 2017) (nixCraft, 2017)
ln –s /var/log/syslog /root/seethelogs
mkdir test_dir
chmod 777
assgn2@perera:~# mkdir test_dir
# ls -ld test_dir
drwxr-xr-x 2 root root 4096 Aug 27 17:31 test_dir
:~#
Remaining Permissions Settings , Changing permissions are given below
assgn2@perera:/# ls
assgn2@perera:/# cd /root
assgn2@perera:~# ls
Downloads ehcp test_dir vst_install_backups webmin_1.810_all.deb
Test Directory Permissions checked
assgn2@perera:~# ls -ltr
Ownercan Read and write , Others can only list
assgn2@perera:~# chmod 644 test_dir/
assgn2@perera:~# ls
assgn2@perera:~# ls -ltr
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References
Access.redhat.com. (2017). Creating a User Account. [online] Available at:
https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/4/html/
Step_by_Step_Guide/s1-starting-create-account.html [Accessed 27 Aug. 2017].
Digitalocean.com. (2017). How To Add and Delete Users on an Ubuntu 14.04 VPS |
DigitalOcean. [online] Available at:
https://www.digitalocean.com/community/tutorials/how-to-add-and-delete-users-on-an-
ubuntu-14-04-vps [Accessed 27 Aug. 2017].
Digitalocean.com. (2017). How To Create a Sudo User on Ubuntu [Quickstart] | DigitalOcean.
[online] Available at: https://www.digitalocean.com/community/tutorials/how-to-create-a-
sudo-user-on-ubuntu-quickstart [Accessed 27 Aug. 2017].
Guide, R. (2017). Free RHCE 7 Study Guide | Linux. [online] Computernetworkingnotes.com.
Available at: http://www.computernetworkingnotes.com/linux/rhce-study-guide/ [Accessed
27 Aug. 2017].
Kb.iu.edu. (2017). In Unix, what is a symbolic link, and how do I create one?. [online] Available
at: https://kb.iu.edu/d/abbe [Accessed 27 Aug. 2017].
Lifewire. (2017). How To Create Users Within Linux Using The "useradd" Command. [online]
Available at: https://www.lifewire.com/create-users-useradd-command-3572157 [Accessed
27 Aug. 2017].
nixCraft. (2017). Understanding UNIX / Linux symbolic (soft) and hard links. [online] Available
at: https://www.cyberciti.biz/tips/understanding-unixlinux-symbolic-soft-and-hard-
links.html [Accessed 27 Aug. 2017].
Tutorials For Kyup.com. (2017). How to install BIND DNS server - Tutorials For Kyup.com.
[online] Available at: https://kyup.com/tutorials/install-bind-dns-server/ [Accessed 27 Aug.
2017].
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