DEV Community: Spam Me

The site on the Russian hosting suddenly became unavailable for some mobile operators. Solution to the problem

Spam Me — Sat, 02 Aug 2025 06:56:38 +0000

Recently, there have been many complaints that a site on a Russian hosting suddenly became unavailable on some mobile operators. It works on one phone, but not on another.

Changing the hosting solves the problem with availability. But there is another option. The author of the article offers his own way to solve the problem without changing the hosting.

First, you need to check the site for availability from different points in Russia. To do this, we will use the service. We enter our domain and click on RU. In about 10 seconds, the availability data will appear.

If you received a response of availability in more than 50 points in Russia, then everything is fine. If in response you received about 10 points of availability, then this is a problem.

Solution:
The essence of the problem is in the incorrectly functioning security certificate, ssl. Perhaps the issuer of the certificate revoked it, but did not tell you.

To check this, go to your hosting and disable redirection from http to https.

Plesk — domain — hosting and dns — hosting:

Uncheck Redirect visitors from HTTP to HTTPS via 301 redirect for SEO

and Save.

Now go back to the service and enter your domain without ssl:

http://site.ru

and press RU. If you get more than 50 points of availability in response, then the problem is in your ssl certificate, it needs to be reissued.

Check results:

Site with faulty ssl

Based on this simple method, you can restore the site's availability to users in Russia.

[Boost]

Spam Me — Sat, 12 Jul 2025 18:43:41 +0000

How to check the availability of a website outside the country of development

Spam Me ・ Jun 17

#webdev #javascript #php #mobile

How to check the availability of a website outside the country of development

Spam Me — Tue, 17 Jun 2025 20:27:50 +0000

Why is it important to check website accessibility from other countries?
Checking website accessibility from abroad is a key task for developers and online business owners targeting the international market. Even if your resource works flawlessly in the country where it was developed, it may be inaccessible or slow to load for users in other regions. The reasons can include blocks, hosting specifics, provider restrictions, or technical issues. The question becomes especially relevant: how can you check how a site works on mobile devices from the perspective of a real user abroad?

Standard monitoring services and their limitations

Most accessibility analyzers on the market use server IP addresses for their checks. Their operation is simple: a script is placed on hosting in the desired location, collects accessibility data (ping, response time, HTTP status codes), and sends it to the main server for display. You don’t need a separate hosting account for this—the script can be placed in the root folder of any site, and it won’t affect the site’s operation since the data traffic is minimal.

The main reason for the popularity of this approach is the low cost and unlimited traffic offered by hosting providers. However, for a comprehensive check, especially for mobile audiences, this is not enough.

Difficulties with testing via mobile networks

An alternative to server-based checks is the use of mobile proxies or creating your own mobile farm. Mobile proxies are intermediary servers that operate on SIM cards of mobile operators and use their IP addresses. However, renting such proxies or setting up your own farm is an expensive endeavor, often complicated by setup and maintenance challenges.

The risk of data simulation

Some unscrupulous services may simulate accessibility data. With a simple script that artificially creates delays in sending requests, it’s easy to imitate a check from any country without having real equipment there. Detecting such simulation is difficult, as services often do not disclose the IP addresses from which checks are performed.

What is a mobile farm?

Creating a mobile farm is not technically complicated: you use a router with SIM card support, connect it to a computer, and manage it with special software. The main problem is the high cost of mobile traffic, which is consumed very quickly even under light loads. A more affordable solution may be to purchase mobile proxies from specialized providers.

How not to get scammed when buying proxies?

The mobile proxy market is full of offers, but there is a risk of being deceived. Some services, under the guise of mobile IP addresses from one country, may provide residential proxies from a completely different location.

To verify the authenticity of a purchased proxy, you can use specialized services. By entering the proxy details in the format username:password@host:port, you can obtain the real IP address behind it. Then, you can check this IP on resources like Check-Host to make sure its geolocation and type match what the proxy seller claims.

Why is real mobile monitoring necessary?

If you are creating a website for a foreign audience, it is important to see it as your users do. Given that most people now access the Internet via mobile devices, testing with them is a necessity.

A site may be blocked in a certain country for various reasons: copyright infringement, spam complaints, non-compliance with local laws or censorship. It is crucial to receive such information promptly, without waiting for it to appear in analytics services—after all, lost traffic means direct financial losses.

Conclusion: a custom solution for real checks

Faced with these challenges, the author concluded that the best solution was to build a custom tool. As a result, a service was developed that checks website accessibility through the IP addresses of real mobile operators in various countries.

Some check points are physically located in different countries, while others are rented via trusted mobile proxy services. If a point becomes unavailable, it is temporarily excluded from the analysis to ensure data accuracy.

This article aims to help those who have wondered: “How can I check how my site works in another country?” We hope it has provided useful information and direction for solving this problem. The project is constantly evolving, and we welcome your suggestions and feedback.

Creating DNS check

Spam Me — Mon, 12 May 2025 16:03:18 +0000

In today's interconnected world, ensuring that DNS changes propagate correctly across different countries is critical for website reliability and user experience. A DNS checking service that tests DNS resolution from multiple global locations helps administrators verify that their records are updated and accessible worldwide. This article outlines the key steps and considerations in building such a service.

Why Global DNS Checking Matters

When DNS records are changed-such as updating an IP address or adding a new subdomain-it can take time for these changes to propagate through DNS servers around the world. A global DNS checking service allows users to:

Verify if DNS changes have propagated in different regions.
Identify potential propagation delays or issues in specific countries.
Ensure consistent user experience regardless of geographic location.

Core Architecture of a Global DNS Checking Service

Distributed DNS Query Nodes

The backbone of a global DNS checker is a network of DNS query nodes (servers) strategically placed in various countries. Each node performs DNS lookups for the requested domain and returns the results to the central service.

Centralized Control and Aggregation

A central server coordinates requests, dispatches them to the global nodes, aggregates the results, and presents them to the user in a clear, visual format-often using maps or tables for easy comparison.

User Interface

The service should offer a simple interface where users can:

Enter a domain name.
Select the DNS record type (A, CNAME, MX, etc.).
View results from each location, with clear indicators for successful or failed resolution.

Technical Implementation Steps

A. Setting Up Global DNS Query Nodes

Deploy virtual machines or containers in data centers or cloud regions worldwide.

Each node should have access to local DNS resolvers to mimic real user queries from that region.

Use Anycast or partner with global DNS providers for broader reach and reliability.

B. Query Execution and Data Collection

When a user submits a request, the central server sends DNS queries to each node.

Each node performs the lookup and returns the raw response (IP address, TTL, etc.).

Results are collected and processed centrally.

C. Visualization and Reporting

Display results on an interactive world map or list, marking each location as successful (✔️) or failed (❌).

Allow users to drill down for detailed information per node, such as the exact DNS response and resolver used.

D. Advanced Features

Support for custom DNS servers, letting users specify which resolvers to test against.

Historical tracking of DNS changes and propagation over time.

API access for integration with other monitoring tools.

Challenges and Considerations

Latency and Caching: DNS results may be cached by intermediate resolvers, so ensure queries bypass caches when possible for real-time accuracy.

Node Reliability: Maintain uptime and consistency across all global nodes.

Security: Protect against misuse, such as DDoS attacks or abuse of the DNS infrastructure.

Example: Existing Tools

Popular services like WhatsMyDNS and DNSChecker use similar architectures, querying dozens or hundreds of DNS servers worldwide and displaying results in real time. These tools help users instantly see how their domain resolves from different countries without manual testing.
Still, building a cross-country checking service can be a simple task, here's an example.

Conclusion

Building a global DNS checking service involves deploying a distributed network of DNS query nodes, aggregating and visualizing results, and providing a user-friendly interface. Such a service is invaluable for web administrators and businesses to ensure their DNS records are accurate and accessible worldwide, minimizing downtime and ensuring a seamless experience for users everywhere.