Change Linux port and Security

1. Configure ssh to login via port 2243 and disable direct root access to the server.

Check port 2243 allready in use
vi /etc/services  and search port number
Open /etc/ssh/sshd_config and change below lines
Port 2243
PermitRootLogin no

2. Configure iptables in the machine and block port 22 to deny ssh access from 192.168.1.9

iptables -A INPUT -p tcp --dport 2243 -s 192.168.1.42 -j REJECT

Reset MySQL root password.

1. Reset the password for mysql root user to 'linux123'.

service mysqld stop
mysqld_safe --skip-grant-tables &
mysql -u root
update mysql.user set password=PASSWORD("linux123") where User='root';
flush privileges;
exit;
service mysqld stop
service mysqld start

2. Make sure you login directly to the mysql console by typing in 'mysql' in konsole.

create a file "  /root/.my.cnf "
[client]
user="root'
password="linux123"

3. Find a way to backup all database in the server at once.

./mysqldump --all-databases > /root/backup/all.sql

MySQL commands

1. Create a database named "linux".

create database <database name>

eg: create database linux;

2. CREATE TABLE named employee_data with coulumns emp_id , name, designation,
age,email address.

create table employee_data(emp_id int(10),name varchar(40),designation
varchar(40),age int(3),emailaddress varchar(50));

3. Enter atleast 10 entries to this table.

insert into employee_data values ('1','joy','linuxadmin','24','abc@gmail.com');

4. take a backup of this database.

./mysqldump -u {user name} -p {database name} > patht/backupname.sql

eg: ./mysqldump -u user -p linux > /root/backup/linux.sql (Note: you can specify any path)