Vyacheslav

Installing and Configuring Config Server Firewall (CSF) in Ubuntu

Config Server Firewall (CSF) – a software product created for automatic server protection.

Installing and Configuring a TFTP Server in Ubuntu

TFTP (Trivial File Transfer Protocol) It is mainly used for initial loading of diskless workstations. TFTP, unlike FTP, does not contain authentication capabilities (although it is possible to filter on the IP address) and is based on the transport protocol UDP.
atftpd server
atftp client

Install:

sudo apt-get install atftpd atftp

The server uses the port: 69/udp
The default directory is /srv/tftp if it does not exist, create:

sudo mkdir -p /srv/tftp
sudo chown nobody /srv/tftp

To start automatically, you need to comment out (put # at the beginning of the line) the start line in /etc/inetd.conf:

#tftp dgram udp4 wait nobody /usr/sbin/tcpd /usr/sbin/in.tftpd –tftpd-timeout 300 –retry-timeout 5 –mcast-port 1758 –mcast-addr 239.239.239.0-255 –mcast-ttl 1 –maxthread 100 –verbose=5 /srv/tftpd

And change the value of the variable USE_INETD in the file /etc/default/atftpd from true to false.
This can be done in any editor, for example using nano:

sudo nano /etc/default/atftpd

(in the editor the key combination Ctrl+O is used to save the changes, and Ctrl+X to exit).

To apply the changes and run atftpd, run the following command:

sudo /etc/init.d/atftpd restart

Done, TFTP server should work, accept and return files from the /srv/tftp directory.

What is the difference between QCIF, CIF, 2CIF, HD1, D1?

The higher the resolution of the recording, the clearer and better the video quality.
– 16CIF – (1.6 Mp, 1408 × 1152)
– 4CIF (D1) – (0.4 Mp, 704х576 – PAL and 704×480 – NTSC)
– 2CIF (HD1 or Half D1) – (0.2 Mp, 704×288 – PAL and 704×240 – NTSC)
– CIF (Common Intermediate Format) – (0.1 Mp, 352×288 – PAL and 352×240 – NTSC)
– QCIF – (0.03 Mp, 176×144 for PAL and 176×120 – NTSC)
– SQCIF – (0.01 Mp, 128 × 96)

HP Printers SNMP OID’s

On the test, I will use the HP LaserJet P2055dn printer.

Here is a list of tested OIDs for obtaining various SNMP information:
1.3.6.1.2.1.43.11.1.1.8.1.1 (Maximum number of copies of toner)
1.3.6.1.2.1.43.11.1.1.9.1.1 (Remaining number of copies of toner)
1.3.6.1.2.1.43.12.1.1.4.1.1 (Toner color)
1.3.6.1.2.1.43.10.2.1.4.1.1 (Number of pages printed)
1.3.6.1.2.1.43.5.1.1.17.1 (Serial number of the printer)

To see a list of all possible oid’s, you can run the command in Linux:

snmpwalk -v 1 -c public 192.168.24.112

You can check the specific oid with the command:

snmpget -v 2c -c public 192.168.24.112 1.3.6.1.2.1.43.11.1.1.9.1.1

Mikrotik SMB – file server configuration

I will use the Mikrotik RB951G-2HnD router as an example.

Connect the media to the USB router.
Let’s look at the status:

store disk print

Format it:

store disk format-drive 1

Reboot the router:

reboot

Add storage:

store add name=share disk=usb1 type=user-manager activate=yes comment="test"

Add share:

ip smb share add name=test max-sessions=15 directory=/test disabled=no comment="test share"

Example of disabling share:

ip smb share disable

Enabling smb:

enable smb

I will give examples of some commands:
ip smb print (view parameters)
ip smb set allow-guests yes/no (allows connection to guest users without entering a password, standard yes)
ip smb set comment TEXT (comment, standard MikrotikSMB)
ip smb set domain NAME (setting the name of the workgroup, standard MSHOME)
ip smb set enabled yes/no (SMB on/off, standard no)
ip smb set interfaces all/wlan1/bridge-local/… (installation of interfaces on which SMB will be started, standard all)

ip smb users add read-only=no name=LOGIN password=PASSWORD disabled=no (user creation)
ip smb users disable (disabling the user)
ip smb users enable (user activation)
ip smb users print (view the list of users)
ip smb users remove (deletion of the user)
ip smb users set read-only=no name=LOGIN password=PASSWORD (user change)

ip smb share enable
ip smb share print (view share list)
ip smb share remove
ip smb share set (changing the parameters of the share)

To get help, use the “?” character on the command line.
To go to the level above – “..”.

Example of configuring the firewall for smb:

add action=accept chain=input disabled=no dst-port=137-138 protocol=udp src-address-list=smb-allow
add action=accept chain=input disabled=no dst-port=137,139 protocol=tcp src-address-list=smb-allow
ip firewall address-list add address=1.1.1.1 disabled=no list=smb-allow

Official documentation:
wiki.mikrotik.com/wiki/Manual:IP/SMB
wiki.mikrotik.com/wiki/Manual:Store

You can also connect a hard drive to the router via the USB-SATA adapter.

How to Download from SVN

To download data from the SVN repository in Ubuntu, you must first install:

sudo apt-get install subversion

In CentOS:

sudo yum install subversion

After installing subversion, you can download data from SVN simply by running the command:

svn checkout http://address

The data will be saved in the current directory.

SQL queries for WordPress

Here are some examples of SQL queries for a WordPress database, where ‘TEXT’ provide your data.

Connecting to MySQL without entering a password

Suppose you need to make the user root can connect to MySQL from localhost without entering a password.

Hard Reset Ergo A500 Best

In order to fully reset the settings on the Ergo A500 Best smartphone to the factory settings and erase the user data, perform several steps:

1) Turn off the device.

2) Press the Volume Up and Power Button simultaneously until the menu appears.

3) Press the Volume Up key to select “Recovery” and confirm the selection with the Volume Down key.
Should appear robot android.

4) Press the Volume Up and Power Button again at the same time.
The recovery menu should appear.

5) By the menu, you can move the volume up and down keys.
In this way, select “wipe data/factory reset” and confirm the selection with the power key.
In the next window, select “Yes – delete all user data” and confirm with the power key.
Let’s wait until the data is erased and the settings are reset.
At the end, in the same way, we select Reboot to reboot the device.

Done.

Install and configure ntopng

Below I’ll describe the installation of ntopng in Ubuntu.
We select the necessary package on http://packages.ntop.org/apt-stable/ and download it:

wget wget http://apt-stable.ntop.org/16.04/all/apt-ntop-stable.deb
sudo dpkg -i apt-ntop-stable.deb

Further we carry out:

sudo apt-get clean all
sudo apt-get update
sudo apt-get install pfring nprobe ntopng ntopng-data n2disk nbox
sudo touch /etc/ntopng/ntopng.start
sudo /etc/init.d/ntopng restart

If new versions of ntopng are released, then you can update by running the commands:

sudo apt-get update
sudo apt-get upgrade

After installation, the configuration file will be located in the /etc/ntopng/ntopng.conf directory
I will give an example of its content:

-w=3000
-d=/var/tmp/ntopng
-G=/var/run/ntopng.pid
--httpdocs-dir /usr/share/ntopng/httpdocs
--local-networks="192.168.0.0/16,10.0.0.0/8,172.16.0.0/16"

Restart / stop / start ntopng with commands:

sudo /etc/init.d/ntopng restart
sudo /etc/init.d/ntopng stop
sudo /etc/init.d/ntopng start

You can check from the console with the command:

sudo /etc/init.d/ntopng status
sudo netstat -tulpn | grep :3000

Open the web interface by typing in the address bar of the browser:
http://HOST:3000

The standard login and password are admin/admin.