With the expansion of online activities and the increasing need for stable access to internet services, the use of Virtual Private Servers (VPS) has become one of the most important tools for professional users. Many individuals and businesses use VPS for hosting websites, applications, APIs, Telegram bots, financial systems, and even VPN services.
However, in countries like Iran, one of the serious challenges for users is the filtering of the VPS server’s IP or domain. This can disrupt users’ access to services, lead to business interruptions, reduced revenue, and damage to customer trust.
In this article, we will examine the reasons for VPS filtering and practical solutions for prevention and risk management.
Main Reasons for Virtual Server Filtering
Filtering a virtual server can create serious problems for businesses and professional users, from cutting off user access to losing brand credibility and reducing revenue. Awareness of the factors that lead to IP or domain filtering is the first step in preventing these unwanted events. In the following, we will examine the most important reasons and behaviors that may cause a VPS to be filtered. Knowing these factors will help you to have a secure, stable, and uninterrupted server by observing the necessary principles.
1. Hosting Unauthorized Content or Content Against Domestic Laws
One of the main reasons for a virtual server being filtered is hosting content that is inconsistent with the country’s domestic laws and regulations. These include publishing sensitive political, religious, or cultural content, hosting obscene or violent files, as well as setting up websites with gambling, betting, or illegal gaming nature. Such activities are quickly identified by regulatory bodies and the associated IP or domain is blocked.
2. Selling or Promoting Circumvention Tools
Selling VPNs, SSH tunnels, proxies, or advertising and teaching methods of bypassing filtering through a website or services based on VPS is another common reason for server filtering. Even if you only have a page containing an introduction or link to these tools, the risk of identification and blocking will be high.
3. Connecting to Filtered Services in Iran
Using a VPS to run Telegram bots, messaging applications that are filtered in Iran, or connecting to APIs and international payment gateways that are blacklisted in Iran can lead to the server being filtered. These connections are usually identified by the national firewall or internet service providers.
4. Suspicious Activities from the Server IP
If the server IP is used for malicious activities, such as sending bulk advertising emails (spam), performing DDoS attacks, or scanning the ports of other systems, the probability of it being filtered or blocked by the destination country or Iran is very high. Sometimes, another user who previously used the same IP may have caused it to be blacklisted.
5. Failure to Observe Security Principles and Updates
Security vulnerabilities in the operating system, content management systems (CMS), or plugins, along with open sensitive ports without access restrictions, can expose your server to intrusion. If compromised, the server may be used for malicious purposes, which not only endangers data security but also increases the likelihood of filtering.
Effective Solutions to Prevent VPS Filtering
1. Using Official and Valid Domains
- Use domains with well-known extensions such as .com, .net, or even .ir (while complying with domestic laws).
- Registering the domain with real information in systems such as WHOIS or IRNIC increases the credibility of your website and reduces the chance of it being filtered. You can learn more about this in the content What is a Domain?.
2. Using CDN and Reverse Proxy (like Cloudflare)
- CDNs direct user traffic through a distributed network of servers and hide the real IP address of your server.
- Cloudflare, BunnyCDN, and Fastly are among the popular CDNs.
- Advantages:
- Hiding the real IP of the server
- Reduced risk of being blocked by the national firewall
- Improved performance, reduced latency, and increased security
- Hiding the real IP of the server
Note: Some CDNs may be fully or partially filtered in Iran. In such cases, you can use a dedicated DNS or alternative CDNs.
3. Regional Access Management to the Server
- If your service’s audience is outside of Iran, you can restrict access to the server for Iranian users using Geo IP filtering or intelligent firewalls.
- Tools like Nginx, CSF, Cloudflare Access Rules provide this capability.
4. Checking the Health and Reputation of the Server IP
- Before using a new IP, be sure to check that:
- It is not on any blacklists
Suggested tool: mxtoolbox.com/blacklists - Be accessible on Iranian networks (tested from the Iranian internet)
- It is not on any blacklists
- If possible, use a Dedicated IP instead of a shared one.
5. Activate a Valid SSL and Use HTTPS
- Installing an SSL certificate from sources like Let’s Encrypt encrypts traffic between the user and the server.
- Using HTTPS, in addition to increasing security, can in some cases prevent the firewall from identifying the type of content.
6. Avoid Directly Hosting Circumvention Services
- Avoid providing or advertising circumvention tools such as VPNs, proxies, or tunnels.
- Uploading even one executable file related to these tools can lead to complete IP blocking.
7. Continuous Monitoring of Traffic and System Logs
- Using professional monitoring tools such as:
- Fail2Ban to prevent suspicious login attempts
- Netdata, Grafana, Zabbix to monitor traffic and unusual behavior
- Fail2Ban to prevent suspicious login attempts
- Regularly reviewing logs can inform you of suspicious activity before filters are applied.
What to do if your VPS is filtered?
If your Virtual Private Server is filtered, it’s important to remain calm and take logical and quick steps to restore access and ensure the continuity of your service. Here are some practical solutions:
1. Change the Server IP
The first and simplest way is to change the server’s IP address. Many reputable VPS providers offer the ability to obtain a new IP by submitting a request in the user panel or support section. In some cases, this process is done instantly and automatically.
2. Change the Domain or DNS Records
If the domain you are using is filtered, you can temporarily disable it and introduce a new domain with fresh DNS records. This will restore user access to the service without the need to change the server IP.
3. Using a CDN or Reverse Proxy
Placing your website or service behind a CDN like Cloudflare or using a Reverse Proxy can be an effective way to bypass filtering. This method hides the real IP of the server and routes traffic through another distributed network that is less likely to be filtered.
4. Submitting a Defiltering Request (If the Content is Legal)
If you are sure that your hosted content does not violate domestic laws, you can submit a defiltering request through the Task Force for Determining Instances of Criminal Content system. This method will be more effective for officially licensed websites, companies, and legal entities.
Conclusion: How to Have a Secure and Unfiltered VPS?
Setting up a virtual server requires intelligence and strict adherence to security and legal considerations. By considering the following, you can minimize the risk of being filtered:
- Using a valid and registered domain
- Utilizing a CDN to hide the real IP address
- Avoiding hosting filtered content or services
- Regularly monitoring traffic and user behavior
- Choosing a dedicated and clean IP address
- Using SSL certificates and encrypting communications
Ultimately, choosing a reputable VPS provider that uses clean IPs, provides adequate support, and has a secure infrastructure is the foundation for stable and secure online activity. If you intend to offer your service in Iran or to Iranian users, you must simultaneously pay attention to technical, legal, and security considerations to prevent potential risks.