Large-Scale IP Network Design: VLAN vs. Single Subnet for 500+ Devices
(Focusing on High-Density Surveillance Projects)
Core Question:
For projects exceeding 250 IP addresses (e.g., 500-camera surveillance systems), is VLAN segmentation mandatory? Many low-voltage engineers face this dilemma: single large subnet or VLAN segmentation? Below, we analyze both approaches, including stability risks and best practices.
Option 1: Single Large Subnet (No VLAN)
Method: Expand the subnet mask (e.g., from /24 to /23).
• Example:
◦ Original: 192.168.0.1/24 (254 IPs, mask 255.255.255.0)
◦ Expanded: 192.168.0.1/23 (510 IPs, mask 255.255.254.0)
◦ Includes two contiguous /24 ranges:
◦ 192.168.0.1–192.168.0.254
◦ 192.168.1.1–192.168.1.254
Pros:
• Simplicity: No VLAN configuration needed.
• Cost-Effective: Works with standard switches (no L3 switch required).
Cons:
• Broadcast Storms: High broadcast traffic risks network instability.
• IP Conflicts: Unmanaged devices may cause address collisions.
Mitigation:
• Bind IPs to MAC addresses (DHCP reservations).
• Maintain a detailed IP assignment log.
Option 2: VLAN Segmentation
Method: Divide into multiple VLANs (e.g., /24 per VLAN).
• For ≤500 IPs: 2 VLANs suffice:
◦ VLAN 10: 192.168.1.1/24 (254 IPs)
◦ VLAN 20: 192.168.2.1/24 (254 IPs)
• For >500 IPs: Add VLAN 30 (192.168.3.1/24).
Requirements:
• Layer 3 switch for inter-VLAN routing.
• Basic VLAN configuration (e.g., creating VLANs 10/20/30).
Pros:
• Stability: Isolated broadcast domains reduce congestion.
• Scalability: Easier troubleshooting and future expansion.
Cons:
• Higher initial cost (L3 switch).
• Requires configuration effort.
Recommendation
Scenario
Approach
Rationale
Large projects
VLAN segmentation
Ensures long-term stability and manageability.
Small/medium projects
Single subnet (/23)
Acceptable if risks are mitigated (IP binding + documentation).
Final Notes:
• For mission-critical systems, VLANs are strongly advised.
• For budget-limited projects, a single subnet can work but demands rigorous IP management.
Need VLAN-Capable Hardware?
For industrial-grade networking solutions, consider Wallys DR4019:
• Chipset: Qualcomm IPQ4019/IPQ4029 (industrial-grade performance).
• Features:
◦ VLAN support for segmented networks.
◦ High stability for large-scale deployments (e.g., 500+ cameras).
◦ Advanced QoS and traffic prioritization.
• Ideal for: Surveillance, enterprise networks, and IoT deployments.
Contact Us:
Email sales1@wallystech.com for quotes or technical specifications.
