How to Configure a Secure Business Network?

Network security is the foundation of every company's IT protection. In this guide, you'll learn how to configure a secure business network using proven practices.

Why Is Network Segmentation Important?

Without segmentation, an attacker gaining access to one computer has access to the entire network. Segmentation limits the range of a potential attack.

Example: An accountant's computer is infected with ransomware. With proper segmentation, the attack is limited to the accounting segment - servers, cameras, and other departments remain safe.

Basic Network Architecture

1. Network Segmentation with VLANs

VLAN (Virtual LAN) allows dividing a physical network into isolated logical segments:

2. Next-Generation Firewall (NGFW)

A traditional firewall is no longer sufficient. NGFW offers:

• IPS/IDS - attack detection and prevention
• Application Control - blocking unwanted apps
• Web Filtering - protection against malicious sites
• SSL Inspection - analyzing encrypted traffic
• Sandboxing - analyzing suspicious files

3. Security Rules Between Segments

The principle of least privilege - allow only what is necessary:

• Employees → Internet: allowed (with filtering)
• Employees → Servers: only necessary services
• Guests → Internet: allowed
• Guests → Internal network: blocked
• IoT → Internet: only required updates
• IoT → Servers: blocked

Network Security Checklist

Hardware

• Managed switches supporting VLANs
• Next-Gen Firewall with IPS/IDS
• Access Points with WPA3 and guest network support
• UPS for critical devices

Configuration

• Network segmented into VLANs
• Inter-VLAN rules defined
• Default passwords changed
• Firmware updated to latest version
• Logging and monitoring enabled

WiFi

• Separate network for employees (WPA3-Enterprise)
• Separate network for guests (isolated)
• IoT on dedicated VLAN
• Strong passwords/802.1X

Most Common Mistakes

1. Flat network - everything in one segment
2. Default passwords - admin/admin on devices
3. No updates - old firmware with vulnerabilities
4. Open WiFi - or WPA2 with simple password
5. No monitoring - no one knows what's happening on the network

Additional Protection

Network Access Control (NAC)

NAC allows you to control which devices can connect to the network. An unknown device is automatically placed in quarantine.

DNS Filtering

Blocking malicious domains at the DNS level - protection before the user visits a dangerous site.

VPN for Remote Work

Employees working remotely should use VPN for secure access to company resources.

How Can We Help?

nex-IT specializes in designing and implementing secure networks:

• Network architecture design
• Firewall and switch configuration
• Security audit
• 24/7 monitoring

Contact us - we'll help you secure your network!