The Apocalypse

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Networked computers ​

Establishing local area networks (LANs) and intranets to enable communication, data sharing, and collaborative work within early digital civilization settlements.

In a post-apocalyptic or survival scenario where rebuilding digital infrastructure is a priority, establishing networked computers is a foundational step toward restoring communication, knowledge sharing, and productivity. This section covers the essential knowledge and practical steps for creating local area networks (LANs) and intranets, enabling connected computing environments within settlements or communities.

Introduction to Networked Computers ​

Networked computers refer to multiple computing devices interconnected to share resources, exchange data, and communicate efficiently. In early digital civilization recovery, the focus is on small-scale, manageable networks such as LANs and intranets, which do not rely on external internet connectivity but provide robust internal communication.

A Local Area Network (LAN) connects computers within a limited area such as a building, compound, or small settlement. An intranet is a private network accessible only to authorized users within an organization or community, often built on top of a LAN infrastructure.

Networked computers enable:

  • File sharing and centralized data storage
  • Collaborative document editing and project management
  • Local email and messaging systems
  • Access to shared printers and peripherals
  • Hosting local websites and knowledge bases

A photo of a small community computer room with several desktop computers connected by visible Ethernet cables and a central network switch on a desk. The room has basic lighting and a whiteboard with network diagrams.

Fundamental Components of a Networked Computer System ​

To build a functional LAN and intranet, you need to understand the core components:

1. Network Interface Cards (NICs) ​

Every computer must have a network interface card to connect to the network. Most modern and many older computers have built-in Ethernet NICs. For wireless connections, Wi-Fi cards or USB adapters are used.

2. Network Cables and Connectors ​

The most reliable and straightforward method to connect computers is via Ethernet cables (Cat5e or Cat6). These cables use RJ45 connectors and support speeds from 100 Mbps to 1 Gbps or more.

3. Network Switches and Hubs ​

A network switch is a device that connects multiple computers on a LAN, directing data packets efficiently to their destinations. Switches are preferred over hubs because they reduce collisions and improve network performance.

4. Routers (Optional) ​

Routers connect different networks and manage traffic between them. In isolated LANs without internet access, routers are less critical but can be used to segment networks or provide DHCP services.

5. Servers and Storage ​

A dedicated server computer can host shared files, intranet websites, email services, and databases. Storage can be centralized on network-attached storage (NAS) devices or shared drives.

6. Power Supply and Backup ​

Reliable power is essential for network devices. Uninterruptible power supplies (UPS) or battery backups help maintain network availability during outages.

An illustration of a simple LAN setup showing four desktop computers connected via Ethernet cables to a central network switch. The switch is connected to a server hosting shared files and an intranet website. The background is white with black line art.

Planning Your Network ​

Before physically setting up the network, planning is crucial:

Assess Your Needs ​

  • Number of computers and devices to connect
  • Types of services required (file sharing, messaging, web hosting)
  • Physical layout of the settlement or building
  • Available hardware and cables

Network Topology ​

The most common and practical topology for early networks is the star topology, where all devices connect to a central switch. This topology simplifies troubleshooting and expansion.

IP Addressing Scheme ​

Assigning IP addresses allows devices to identify each other on the network. Use private IP address ranges such as:

  • 192.168.x.x
  • 10.x.x.x
  • 172.16.x.x to 172.31.x.x

A simple scheme is to assign static IPs or use a DHCP server to automate address assignment.

Security Considerations ​

Even in isolated networks, security is important to prevent unauthorized access or data corruption. Use strong passwords, restrict physical access to network hardware, and consider firewalls on servers.

Setting Up the Physical Network ​

Cabling ​

  • Use quality Ethernet cables (Cat5e or Cat6) with proper connectors.
  • Keep cables organized and labeled.
  • Avoid running cables near electrical wiring to reduce interference.

Connecting Devices ​

  • Plug each computer’s Ethernet port into the network switch.
  • Connect the server and any NAS devices to the switch.
  • Power on all devices and verify link lights on the switch ports.

Testing Connectivity ​

  • Use the ping command to test communication between computers.
  • Verify that all devices can reach the server and each other.

A close-up of hands plugging an RJ45 Ethernet cable into a network switch port. The switch has multiple lit LEDs indicating active connections.

Configuring Network Settings ​

Static IP Configuration ​

On each computer:

  • Assign an IP address within the chosen subnet (e.g., 192.168.1.10).
  • Set subnet mask (usually 255.255.255.0).
  • Set default gateway (if using a router; otherwise, leave blank).
  • Configure DNS servers if applicable.

DHCP Server Setup ​

If available, configure a DHCP server on the router or server to automatically assign IP addresses. This simplifies network management as devices join or leave.

Name Resolution ​

For ease of use, set up a local DNS server or use hosts files on each computer to map computer names to IP addresses.

Building the Intranet ​

An intranet is a private network that hosts internal websites, file repositories, and communication tools.

Web Server Setup ​

  • Use lightweight web servers such as Apache, Nginx, or even simple Python HTTP servers.
  • Host documentation, schedules, announcements, and knowledge bases.
  • Ensure web server security by restricting access to trusted users.

File Sharing ​

  • Use network file sharing protocols such as SMB/CIFS (Windows shares) or NFS (Unix/Linux).
  • Set up shared folders with appropriate permissions.
  • Centralize important documents and backups.

Email and Messaging ​

  • Deploy simple mail servers like Postfix or Exim for internal email.
  • Use open-source messaging platforms (e.g., Mattermost, Rocket.Chat) for real-time communication.

Collaborative Tools ​

  • Host wiki software (e.g., MediaWiki) for collaborative documentation.
  • Use version control systems (e.g., Git) for managing shared projects and code.

A computer screen displaying a simple intranet homepage with links to shared files, messaging, and documentation. The illustration is black line art on a white background.

Maintaining and Expanding the Network ​

Regular Backups ​

  • Schedule backups of critical data and configuration files.
  • Store backups on separate physical media or offsite locations.

Monitoring ​

  • Use network monitoring tools to track device status and traffic.
  • Identify and resolve connectivity issues promptly.

Adding New Devices ​

  • Follow the established IP addressing and security protocols.
  • Label and document new connections.

Troubleshooting Common Issues ​

  • Check physical connections and cable integrity.
  • Verify IP configurations and network settings.
  • Restart network devices if necessary.

Wireless Networking Considerations ​

While wired Ethernet is preferred for reliability and speed, wireless networking can supplement or replace cables in some scenarios.

Wi-Fi Setup ​

  • Use wireless access points (APs) connected to the LAN.
  • Secure Wi-Fi with WPA2 or WPA3 encryption.
  • Limit signal range to prevent unauthorized access.

Mesh Networks ​

  • Deploy mesh Wi-Fi systems to cover larger areas without extensive cabling.
  • Mesh nodes communicate with each other to extend network coverage.

Wireless Limitations ​

  • Wireless networks are more susceptible to interference and security risks.
  • Speeds and latency may be lower than wired connections.

Hardware Salvage and Repurposing ​

In survival scenarios, new hardware may be scarce. Salvaging and repurposing existing equipment is essential.

Sources of Hardware ​

  • Old office buildings, schools, or data centers.
  • Discarded consumer electronics.
  • Donations or barter within the community.

Testing and Repair ​

  • Test salvaged network cards, cables, and switches.
  • Repair broken connectors or replace cables.
  • Clean dust and corrosion from equipment.

Compatibility ​

  • Ensure hardware supports standard Ethernet protocols.
  • Use drivers compatible with the operating systems in use.

Software Choices for Networked Computers ​

Choosing the right software stack is critical for network stability and usability.

Operating Systems ​

  • Lightweight Linux distributions (e.g., Debian, Ubuntu Server) are ideal for servers.
  • Windows or Linux can be used on client machines depending on availability.

Network Services ​

  • DHCP, DNS, and file sharing services should be configured carefully.
  • Use open-source software for flexibility and community support.

Security Software ​

  • Firewalls and antivirus tools help protect the network.
  • Regularly update software to patch vulnerabilities.

Case Study: Setting Up a LAN in a Small Settlement ​

Imagine a community of 20 people with 10 computers spread across several buildings. The goal is to create a LAN for file sharing, messaging, and hosting a knowledge base.

Step 1: Hardware Assembly ​

  • Salvage 10 computers with Ethernet NICs.
  • Acquire or salvage a 16-port network switch.
  • Obtain Cat5e cables of appropriate lengths.

Step 2: Physical Setup ​

  • Run Ethernet cables from each building to a central network room.
  • Connect all computers and the server to the switch.

Step 3: Network Configuration ​

  • Assign static IP addresses in the 192.168.10.x range.
  • Set up a Linux server with Samba for file sharing.
  • Install a lightweight web server hosting a MediaWiki site.

Step 4: User Training ​

  • Teach users how to access shared files and the intranet.
  • Establish protocols for data backup and security.

Step 5: Maintenance ​

  • Schedule weekly backups.
  • Monitor network performance and troubleshoot issues.

Conclusion ​

Establishing networked computers through LANs and intranets is a critical step in rebuilding digital infrastructure in early digital civilization. It enables efficient communication, resource sharing, and knowledge management within communities. By understanding the hardware, software, and organizational requirements, survivors can create resilient and scalable networks that form the backbone of a renewed knowledge economy.

For further details on communication technologies beyond local networks, see Cross-settlement wireless communication.

A group of people gathered around a table with laptops connected to a local network, collaborating on a project with visible network cables and a network switch in the background.