How to Enhance Overall Architecture Security Through Accessories Like Firewalls, Network Cards, and Switches

In the digital age, security threats facing enterprise IT architectures grow increasingly complex—ranging from external network attacks like distributed denial-of-service (DDoS) and SQL injection to internal risks such as unauthorized access and data breaches. While core devices like servers (e.g., bare-metal servers) form the foundation for stable business operations, accessories such as firewalls, network interface cards, and switches serve as the “security guardians” and “traffic commanders” within the network. They are not merely auxiliary components but the central pillars for building a multi-layered, intelligent security defense system.

Firewalls: The First Line of Defense Against External Threats

As the “gatekeeper” of the enterprise network perimeter, firewalls serve as the initial barrier against external malicious traffic. Their core value lies in filtering network packets based on predefined security policies, allowing legitimate traffic while blocking potential threats. However, as attack methods evolve, traditional packet-filtering firewalls no longer meet security requirements. Enterprises must select and configure firewalls strategically to maximize their security effectiveness.

Choose the Right Firewall Type Based on Business Scenarios

Not all firewalls offer identical functionality; different types suit varying security requirements. For small and medium-sized enterprises with simple network structures, stateful inspection firewalls provide a cost-effective solution. They track network connection states (such as the TCP three-way handshake) to prevent forged connection requests. For large enterprises or industries with stringent security standards—such as finance and healthcare—next-generation firewalls (NGFWs) are indispensable. These firewalls integrate intrusion prevention (IPS), application layer inspection, and virtual private network (VPN) capabilities to identify and block advanced threats concealed within application traffic (e.g., malicious code transmitted via WeChat or email).

Implement Fine - Grained Access Control Policies

Firewall effectiveness hinges on policy configuration. Many organizations fall into the trap of overly permissive policies (e.g., allowing all external traffic to access internal web servers), creating security vulnerabilities. Adopting the principle of least privilege access control can mitigate this:

1, Segment the network into distinct security zones, permitting only essential traffic between zones.

2, For specific scenarios like remote employee access, deploy a VPN + Multi-Factor Authentication (MFA) combination. The firewall first verifies the remote user's identity before granting access to internal resources, preventing unauthorized intrusions due to compromised passwords.

Enable Real-Time Monitoring and Automated Response

Threats are dynamic; firewalls cannot be set and forgotten. Organizations must activate real-time logging and threat monitoring capabilities:

1, Integrate the firewall with the enterprise's Security Information and Event Management (SIEM) system for centralized analysis of abnormal traffic.

2, Configure automated response rules to reduce threat response time and prevent delays from manual intervention.

Network Interface Cards: The “Security Gateway” for Terminal - to - Network Connections

Network interface cards (NICs) serve as the “bridge” connecting servers, workstations, and networks. While many focus solely on their speed (e.g., 10G, 100G), their security capabilities are often overlooked. In reality, modern NICs have become a critical component of endpoint security. Leveraging their hardware-level security features, enterprises can reduce security pressure on server operating systems and prevent threats from infiltrating through endpoints.

Select Network Interface Cards with Hardware-Level Encryption Capabilities

Data transmission over networks is vulnerable to eavesdropping. Traditional server-based software encryption consumes significant CPU resources, with particularly noticeable impacts in high-traffic scenarios like e-commerce platforms. Network interface cards equipped with hardware encryption modules offload encryption and decryption tasks from the CPU to the NIC hardware. This approach enhances encryption efficiency while preventing CPU resource depletion that could degrade service performance. For instance, when bare-metal servers process sensitive data like user payment information, hardware-encrypted NICs ensure end-to-end data transmission encryption without compromising server processing speed.

Enable NIC-Based Access Control (MAC Binding)

Internal network security is often overlooked. Unauthorized devices (e.g., employees' personal laptops) accessing internal networks may introduce viruses or steal data. By binding NIC MAC addresses to switch ports, enterprises can strictly control endpoint access:

1, Record legitimate device MAC addresses (e.g., company servers, employee workstations) in the switch's Access Control List (ACL).

2, The switch permits only packets from bound MAC addresses to pass through. Devices with unregistered MAC addresses cannot communicate with the internal network via their NICs, effectively blocking “unauthorized endpoint access.”

Use Network Cards with Traffic Filtering and Anomaly Detection 

Certain high-end network cards support hardware-level traffic filtering. Enterprises can configure rules on these cards to intercept malicious traffic before it reaches the server operating system. For example:

1, Filter packets with abnormal header information (e.g., excessively long IP addresses), as such packets are often used in network scanning attacks.

2, Set traffic thresholds to automatically discard excess packets, preventing server paralysis during traffic spikes.

Switches: The “Traffic Commanders” Safeguarding Internal Networks

Switches manage data forwarding within internal networks. Improperly configured switches can become vulnerabilities—such as VLAN misconfigurations triggering broadcast storms or unauthorized port access causing data leaks. By optimizing switch configurations, enterprises can build a “segmented and controllable” internal network to prevent threats from spreading across departments.

Divide Internal Networks into Segments Using VLANs

By default, an enterprise internal network forms a single large broadcast domain. If a device becomes infected, the virus can spread to all network devices via broadcast packets. Virtual Local Area Network (VLAN) technology divides physical switches into multiple logical “small networks.” Devices within different VLANs cannot communicate by default and require firewall authorization to interconnect.

Enabling Switch Port Security and Loop Detection

Switch ports serve as the “entry points” for internal network connections. Improper port configuration can lead to risks such as network loops and unauthorized access. Enterprises must implement security measures for switch ports:

1, Port Security: Limit the number of MAC addresses a single switch port can learn (e.g., set to 1). If multiple MAC addresses are detected on a port (potentially indicating illegal network expansion via small routers or switches), the switch automatically disables that port to prevent “illegal network expansion risks.”

2, Loop Detection: Enable the Switching Tree Protocol (STP) or Rapid Switching Tree Protocol (RSTP). If a network loop is detected (e.g., two cables mistakenly connected to the same switch port), the switch automatically blocks redundant ports to prevent broadcast storms from crippling the internal network.

Deploy Layer 3 Switches with Access Control and Traffic Monitoring

For large enterprises with complex internal networks, Layer 3 switches (supporting both Layer 2 data forwarding and Layer 3 IP routing) better meet internal security requirements. Compared to traditional Layer 2 switches, Layer 3 switches offer two core security advantages:

1, VLAN-to-VLAN Access Control: Layer 2 switches rely on firewalls to manage communication between VLANs, whereas Layer 3 switches can directly configure access rules based on IP addresses. This reduces firewall forwarding pressure while improving communication response times between VLANs.

2, Real-Time Traffic Monitoring: Layer 3 switches can collect traffic data across different network segments.

Build a Multi-Layered Security Architecture with “Three Core Accessories”

Firewalls, network interface cards (NICs), and switches are not isolated security components. They must work together to form a multi-layered security system comprising “perimeter defense + endpoint protection + internal control.” For example:

1, Firewalls intercept external malicious traffic at the network perimeter;

2, NICs on core servers encrypt sensitive data transmission and filter invalid traffic at the endpoint;

3, Switches segment internal networks via VLANs, controlling inter-departmental traffic to prevent threat propagation. 

Amid digital transformation, enterprises must not only prioritize the performance of core equipment like servers but also emphasize the security configuration and functional selection of “small components” such as firewalls, network interface cards, and switches. Only by establishing a “full-link” security defense system can organizations effectively counter increasingly complex cyber threats and ensure stable, secure business operations.