All posts by ServerAdmin

Basic MySQL operations I

In this post, I will present few basic commands for MySQL administration. You’ll see how to create a database, create user, assign a database for specific user, etc. First I suppose that you have root password set and that you know it… (in next posts I will present few steps to set this password or to recover it…)

Log in to mysql console:

 
[root@hydra mysql]# mysql -u root -p
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 248
Server version: 5.0.45 Source distribution
 
Type 'help;' or '\h' for help. Type '\c' to clear the buffer.
 
mysql>

Here you can see server version (in this case 5.0.45). With next command you can see all databases

 
mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| birds              |
| mysql              |
| private             |
| bdd1             |
| test               |
+--------------------+
6 rows in set (0.05 sec)
 
mysql>

If you want to create a new database, enter next command (remember that all SQL commands must be terminated with ; )

mysql> create database db1;
Query OK, 1 row affected (0.00 sec)

Now we need to assign a user to newly created database. Also, we need to grant him all privileges for this database but restrict access and operations on another databases (except test database)

mysql> CREATE USER 'db1'@'localhost' IDENTIFIED BY 'db1pass';
Query OK, 0 rows affected (0.02 sec)
 
mysql> GRANT ALL PRIVILEGES ON db1.* TO 'db1'@'localhost' IDENTIFIED BY 'db1pass';
Query OK, 0 rows affected (0.01 sec)
 
mysql> quit;
Bye

To add readonly account you can set next privileges

GRANT SELECT ON db1.* TO 'db1'@'%';

If you replace “localhost” with “%”, the user will be able to connect from remote host.

After this you can repeat step from the beginning and test new user account. In next posts I will present phpMyadmin

How to test BIND version running on DNS server?

BIND, or Berkley Internet Name Domain, is an Internet naming system used for DNS, which allows you to find the sites you are looking for. BIND contains entries for DNS names, so for example, if you type www.bla.com into your browser, the record tells your browser at what IP address to find the site. If you need to test BIND version running on DNS server, you can use next commands:

Windows

nslookup -q=txt -class=CHAOS version.bind 192.168.51.250

Linux

#dig -t txt -c chaos VERSION.BIND @192.168.51.250

After this, you should get next answers

Windows

Server:  my.server.net
Address:  192.168.51.250
 
version.bind    text =
 
        "9.3.4-P1"
version.bind    nameserver = version.bind

The Linux users will have more details about server

[root@server ~]# dig -t txt -c chaos VERSION.BIND @192.168.51.250
 
; <<>> DiG 9.3.4-P1 <<>> -t txt -c chaos VERSION.BIND @192.168.51.250
; (1 server found)
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 44906
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 0
 
;; QUESTION SECTION:
;VERSION.BIND.                  CH      TXT
 
;; ANSWER SECTION:
VERSION.BIND.           0       CH      TXT     "9.3.4-P1"
 
;; AUTHORITY SECTION:
VERSION.BIND.           0       CH      NS      VERSION.BIND.
 
;; Query time: 54 msec
;; SERVER: 192.168.51.250#53(192.168.51.250)
;; WHEN: Mon Mar 23 20:09:57 2009
;; MSG SIZE  rcvd: 65

To hide your version of bind, add the following value to named.conf (now the commands shown above won’t return Bind version)

options {
.....
version "[SECURED]";
};

Save named.conf and restarted named.

Remember the fact that Bind is the most popular Internet naming system but not the only one…