Linux – Page 3

Installing and configuring iRedMail

Below is an example of installing iRedMail on Ubuntu/Debian.
On the test I will install iRedMail on Ubuntu 18.04 LTS.

NAT Modules for VPN, FTP, SIP

Let’s say SNAT or masquerading is configured on a Linux server, for example, as I described in article Ubuntu IP Masquerading (NAT). But if many NAT clients connect to external PPTP, FTP, SIP servers for NAT, then they will have connection problems.

Installing and using ipt_NETFLOW

ipt_NETFLOW – fast NetFlow traffic sensor, consists of a kernel module and iptables, supports NetFlow v5, v9, v10(IPFIX).

Installing and using Nfsen

Nfsen is an open-source Netflow collector and analyzer that displays statistics in a web interface in the form of graphs.

Installing and using Nfdump

Nfdump is a collection of tools for collecting and processing netflow data.

Installing VirtualBox on Ubuntu

On Ubuntu/Debian, VirtualBox is installed with the following command:

Installing and configuring PPTPd server

Below I will describe how pptpd is installed and configured. On the test I will install in Ubuntu Server 18.04.

Asterisk Call Forwarding

Let me give you an example of setting call forwarding in Asterisk.
For example, on Grandstream IP phones, you can enable redirection by the functions of the phone itself, but if the phone is far away and there is no way to do it on it, but it is possible to log in using the SIP number of this phone, then to activate call forwarding, you can make a voice menu when dialing a certain number, for example, *21 to activate call forwarding and enter the phone number to which calls will be forwarded, and *22 to cancel call forwarding.

Installing and configuring fprobe

On the test, I will install the fprobe sensor, which will collect statistics from network interfaces and transmit it to the collector.

How to allow all outgoing ports in CSF

Once on the same server running cPanel, CSF (Config Server Firewall) and LFD (Login Failure Daemon) I wanted to run the Speedtest CLI, but it did not start because it could not connect to the servers, I opened the CSF settings through the WHM panel (at the very bottom menu “ConfigServer Security & Firewall” – “Firewall Configuration”), where he discovered that only a few outgoing ports were open: