In actual applications, more and more companies choose to bind native IP on Hong Kong servers to obtain true attribution, improve availability, bypass regional restrictions, enhance platform reputation and other purposes. However, although native IP has advantages, it also brings higher security risks.

　　Native IP is usually a "fixed public IP" and is easily targeted by hackers, crawlers, scanners or DDoS attackers when exposed to the public network. Once maliciously exploited, the server load will soar at the least, and business interruption, data leakage and reputation damage will occur at the worst. Therefore, how to effectively improve network security after enabling native IP on Hong Kong servers has become an important topic for enterprise network architecture design and daily operation and maintenance.

　　Main security risks faced by native IP servers:

　　1. Frequent DDoS attacks. Native IP is often used as a DDoS target because it is easy to be identified by scanners, used by anti-generators or maliciously attacked by competitors, resulting in large traffic attacks such as TCP SYN Flood, UDP Flood, HTTP Flood, etc.

　　2. Brute force cracking and port scanning. Attackers scan common ports such as 22/3389/3306 and try to brute-force crack SSH, RDP, and database passwords. If they are not blocked in time, data leakage or permission hijacking will occur.

　　3. System vulnerability exploitation. Some native IP servers may be implanted with WebShell, XSS Trojans, or used as springboards for secondary attacks because they have not updated system components or use default services (such as PHP, Apache, Tomcat, etc.).

　　4. IP reputation declines. If the IP is used to send spam, build illegal websites, and is frequently reported by users, it is easy to enter blacklists such as DNSBL and Spamhaus, which seriously affects server stability and business accessibility.

　　Overview of strategies to improve native IP network security

　　In order to effectively protect the network security of Hong Kong native IP servers, a layered defense system should be built from four dimensions: network layer, application layer, security service, and daily operation and maintenance.

　　1. Network layer protection: anti-scanning, anti-intrusion

　　Enable the firewall, reject all inbound traffic by default, and only release necessary ports. Use non-standard ports to hide services and configure port speed limits, such as limiting the number of connections per IP. Combine with Fail2ban or DenyHosts to automatically ban brute force IPs. Use ACL access control lists to limit access scope (only open to whitelists).

　　2. Application layer reinforcement: control permissions and audit logs

　　Minimize system permissions, close root login, and use sudo management. Regularly check weak password accounts and clean up idle accounts. Add WAF protection to applications to prevent SQL injection, XSS, and CSRF. Configure Nginx or Apache access restrictions and Referer verification. Enable system and Web log records to assist security audits.

　　3. DDoS protection: high availability strategy

　　Introduce local Hong Kong DDoS cleaning services (such as cleaning nodes provided by PCCW and HKBN). If business needs, use the "dynamic and static separation + cache back to source" method to reduce direct exposure of native IPs. Add a reverse proxy structure upstream to hide the real source server IP.

　　4. Security operation and maintenance habits: continuous visibility

　　Regularly update system and service components and fix CVE vulnerabilities. Configure bastion host access and prohibit public network from opening management ports. Use the security operation and maintenance platform to monitor abnormal traffic. For sudden access, alarm emails can be automatically triggered, and security audits are conducted once a month to evaluate the IP security level.

　　Practical configuration: How to protect native IP security on Hong Kong servers

　　The following is a set of practical and feasible recommended steps:

　　Step 1: Change the default port + security authentication

　# Changing the SSH default port
　sudo sed -i 's/#Port 22/Port 22022/' /etc/ssh/sshd_config
　sudo systemctl restart sshd

　# Disable Root Login
　sudo sed -i 's/#PermitRootLogin yes/PermitRootLogin no/' /etc/ssh/sshd_config

　　Step 2: Configure Firewalld to deny scanning

　# 开启firewalld
　sudo systemctl start firewalld
　sudo firewall-cmd --permanent --zone=public --add-port=22022/tcp
　sudo firewall-cmd --reload

　　By default, all access except SSH is denied, and HTTP, HTTPS and other service ports are opened as needed.

　　Step 3: Install Fail2Ban to prevent cracking

　sudo yum install fail2ban -y
　sudo systemctl enable fail2ban
　sudo systemctl start fail2ban

　　Configure /etc/fail2ban/jail.local, and set policies such as blocking IP for 10 minutes after 3 failed login attempts.

　　Step 4: Use reverse proxy + self-built cache

　　Deployment structure: User access → CDN/WAF (Hong Kong node) → Nginx reverse proxy → native IP host

　　Use Nginx to build a cache server, hide public network requests in the proxy layer, and only communicate back to the source internally. All external logs are written after being filtered by the proxy server to reduce the pressure on the main service.

　　The widespread use of native IP of Hong Kong servers is not only an opportunity for enterprises to improve their business coverage and brand credibility, but also brings unprecedented network security challenges. Faced with risks such as fixed IP exposure, clear attack paths, and concentrated traffic, only by building a strong security system through active defense, layered isolation, and continuous operation and maintenance can we take the initiative in the fiercely competitive global market. Network security is not a one-time achievement, but a systematic project throughout the entire server life cycle.