Author Archives: Vyacheslav

Remote Wake-up of the computer (Wake On LAN)

To remotely turn on the computer, you need to have an ATX power supply, a motherboard with Wake On LAN and BIOS enabled, a Wake On LAN network adapter.

When Wake On LAN is supported, the shut down computer powers the AC adapter that is in low power mode and listens to all packets going to its MAC address without answering them. If a Magic Packet comes, the network adapter sends a signal to turn on the power of the computer.

View active network adapters:

ifconfig

You will need the ethtool package, if it is not installed on the system, you must perform the installation:

sudo apt-get install ethtool

Check for WOL support:

sudo ethtool eth0 | grep Wake

The result of the command if the network card is working with WOL and it is enabled:

Supports Wake-on: g
Wake-on: g

The result of the command when WOL is off:

Wake-on:d

Possible result letters (taken from man ethtool information):

p Wake on PHY activity
u Wake on unicast messages
m Wake on multicast messages
b Wake on broadcast messages
a Wake on ARP
g Wake on MagicPacket™
s Enable SecureOn™ password for MagicPacket™
d Disable (wake on nothing). This option clears all previous options.

To turn on WOL:

sudo ethtool -s интерфейс wol g

Turning on the computer:

apt-get install wakeonlan
wakeonlan -p 50000 00:01:02:03:04:05

-p indicates the UDP port number.

On the Internet, there are also many sites and applications for phones that allow you to send a package to a remote computer.

See also:
Using ethtool

Using ethtool

ethtool – a utility for configuring network interfaces in Linux.

You can install ethtool in Ubuntu / Debian using the command:

sudo apt-get install ethtool

Let’s look at the names of network interfaces:

ifconfig -a

Switch to root, as some commands require elevated privileges:

sudo -i

Example of viewing eth0 settings:

ethtool eth0

Example of viewing information about the network interface driver:

ethtool -i eth0

Viewing Network Interface Statistics:

ethtool -S eth0

View auto-negotiation settings:

ethtool -a eth0

The LED blinks for 3 seconds on the specified network interface:

ethtool -p eth0 3

Network Interface Test:

ethtool -t eth0 online/offline

View the current and maximum size of TX and RX buffers:

ethtool -g eth0

Manual speed setting of 100 Mb Full Duplex on the specified network interface (the specified parameters will be reset after the system restart):

ethtool -s eth0 speed 100 duplex full

Viewing help about ethtool:

ethtool -h

See also:
Configuring the Network in Linux
Changing TX and RX network interface buffers in Linux
Remote Wake-up of the computer (Wake On LAN)

How to configure PPPoE in Mikrotik

To configure the PPPoE connection, open the web interface of the device by opening the link http://192.168.88.1 (its standard ip address) in any browser.
Then in the menu, open the tab “PPP“, push the button “Add” (red plus if via Winbox), choose “PPPoE Client“.
In the window that opens, specify the connection parameters, in the first tab “General” we indicate:

Name: (any word in English, this will be your PPP connection name)
Interfaces: ether1 (specify the WAN interface that looks towards the provider or PPPoE server)

Next, open the tab “Dial Out” and specify:
User: (PPP user name)
Password: (password)
Put a tick “Add Default Route” (if the routes are to be set automatically)
Put a tick “Use Peer DNS”

Click “OK“, after which the connection will be configured and the letter “R” which means that the connection was successful.
If the letter does not appear, you can see the logs by clicking on the menu on the left “Log“, by which you can determine the connection error.

Monitoring Linux ISG in Zabbix

Today I wanted to monitor Linux ISG sessions in Zabbix.

By entering the command on one of the servers:

/opt/ISG/bin/ISG.pl show_count

Saw the following:

Approved sessions count: 2021
Unapproved sessions count: 2

The Zabbix agent on the server has already been installed, so it opened its configuration file (in the nano editor, the Ctrl+X keys for the exit, and y/n for saving or canceling the changes):

nano /etc/zabbix/zabbix_agentd.conf

Invented and added the following code:

UserParameter=isg.approved, /opt/ISG/bin/ISG.pl show_count | grep "Approved sessions count:" | awk '{print $4}'
UserParameter=isg.unapproved, /opt/ISG/bin/ISG.pl show_count | grep "Unapproved sessions count:" | awk '{print $4}'

We will allow Zabbix agent to work as root with the user specifying:

AllowRoot=1

Restart the Zabbix agent to apply the changes:

sudo /etc/init.d/zabbix-agent restart

On the Zabbix server, create an ISG template, add the data elements to it, specifying the type – Zabbix agent, and the keys: isg.approved, isg.unapproved.
Create graphics for the created data items.

Apply the template to the desired nodes of the network.

Done.