IT Blog

What is DHCP and how does it work?

DHCP – Dynamic Host Configuration Protocol in a TCP / IP network.

Resetting the ABillS administrator password

To reset the administrator password, you need to execute the following SQL query in the ABillS database:

UPDATE admins SET password=ENCODE('NEW_PASSWORD', 'test12345678901234567890') WHERE aid=1;

Where test12345678901234567890 variable $conf{secretkey} in the file /usr/abills/libexec/config.pl.

Allow insecure connections to POP3 / IMAP iRedMail

In order to be able to connect to POP3 / IMAP without STARTTLS, you need to open the Dovecot configuration file:

sudo nano /etc/dovecot/dovecot.conf

Edit the two parameters listed below:

disable_plaintext_auth=no
ssl=yes

To return the parameters of the secure connection to POP3S / IMAPS back:

disable_plaintext_auth=yes
ssl=required

After the changes in the Dovecot configuration, you need to restart it:

sudo /etc/init.d/dovecot restart

Ubuntu IP Masquerading (NAT)

For example, I will configure IPv4 masquerading (NAT) on Ubuntu Server.
First you need to enable packet forwarding in /etc/sysctl.conf so that traffic can walk between different network interfaces.
Let’s check the current status:

Kingston SSD Firmware Update

On the test, I will update the SSD firmware of the Kingston SV300S37A 120Gb drive.

1) Download the official utility Kingston SSD Manager with firmware upgrade
https://www.kingston.com/en/support/technical/downloads/90683

2) Run the downloaded utility and if there is a firmware newer, the “Update to firmware …” button will be displayed, and click it to start the update process, which will last a few seconds.

Done, watch the video as I did:

Installing ISC DHCP for ABillS

Here is an example of the installation of the ISC DHCP server for ABillS in Ubuntu Server.

Switch to the root user:

sudo su

Install package:

apt-get install isc-dhcp-server
ln -s /usr/abills/Abills/modules/Dhcphosts/leases2db.pl /usr/abills/libexec/leases2db.pl

Run:

/usr/abills/libexec/leases2db.pl -d LEASES=/var/lib/dhcp/dhcpd.leases

Change owner of a file:

chown www-data /etc/dhcp/dhcpd.conf

Open the config.pl in the Editor:

nano /usr/abills/libexec/config.pl

Add options:

$conf{DHCPHOSTS_CONFIG}='/etc/dhcp/dhcpd.conf';
$conf{DHCPHOSTS_LEASES}='/var/lib/dhcp/dhcpd.leases';
$conf{DHCPHOSTS_RECONFIGURE}='/usr/bin/sudo /etc/init.d/isc-dhcp-server restart';

Open in the Editor:

nano /etc/sudoers

Add the string making the ability to run a service system:

www-data   ALL = NOPASSWD: /etc/init.d/isc-dhcp-server

Go to the Abills Web interface, open the menu "settings"-"IP (DHCP)"-"Network IP (DHCP) Network", add the network if needed, then "Show, reconfigure the dhcp" and "Reconfigure".

See if the isc-dhcp-server command:

/etc/init.d/isc-dhcp-server status

Logs are written to the file/var/log/syslog

You can also configure the export of DHCP history to see it in the “Report” – “DHCP History” menu.
To do this, make a link:

ln -s /usr/abills/Abills/modules/Dhcphosts/dhcp_log2db.pl /usr/abills/libexec/dhcp_log2db.pl

Separating DHCP logs into a separate file as I wrote in the article below and adding to the Startup script with the command:

tail -F /var/log/dhcpd.log | /usr/abills/libexec/dhcp_log2db.pl