3.1 Current Analysis

A LAN network is designed and set up, paying particular attention to adapting the operating system kernel to the functions of network filters. The transmission of general data accesses (network shares) is performed via Gigabit Ethernet. A passively cooled TX-Team Nettop running Ubuntu LTS Xenial Xerus serves as the base and server system, connected to a MikroTik hEX lite RB750r2 MPLS router, which forwards the data stream to a ZBOX ZOTAC CI323 nano repurposed as a gateway. The external interfaces include 2x2 1Gigabit Ethernet and 5x1Gigabit Ethernet ports.

Out of special interest and research curiosity, two routing distributions are additionally integrated into the network transmission. These include the proprietary RouterOS with iptables and the open-source pfSense distribution based on FreeBSD and the pf packet filter. A Cisco Systems router was briefly used for testing, originally intended for household network distribution, but removed due to interference and replaced with a small 5-port ISY INW1000 switch. All incoming and outgoing traffic is filtered by two packet filters and simultaneously extended by a wide range of network services.

On the server, a modular compiled InspIRCd (C++), Eggdrop (TCL), and a modified Limnoria/Supybot (Python) are running. Additionally, clients and programs from custom applications, e.g., Google API, SQL databases, and RSS services, are used for querying topic-oriented information. Virtual machines are temporarily connected for testing or extensions, such as VPN connections. Note that virtual interfaces communicate via a virtual Host Only network rather than NAT. A dynamic DNS was configured for local web presence exchange in the WAN. Backup is performed using Clonezilla, with incremental backups via SSH or FTP from a laptop. The entire system is designed for minimal energy consumption and silent, maintenance-free continuous operation.