DHCP – Dynamic Host Configuration Protocol in a TCP / IP network.
Continue reading “What is DHCP and how does it work?”Author Archives: Vyacheslav
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
See also:
How to enable SMTP without SSL on port 25 in iRedMail / Postfix
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
See also my articles:
Installing and configuring a dhcp server, isc-in Ubuntu
Packet capturing with tcpdump