Website Opens on One Device But Not Others? (Fixing DNS & Cache)
Website Opens on One Device But Not Others?
Summary
If a website works on your phone (using mobile data) but not your laptop (on Wi-Fi), or works on one PC but not another, the problem is usually DNS Caching or ISP Propagation. This means one device is still trying to use an old “address” for the site while the other has the new one.
Overview
When you visit a website, your device “remembers” its IP address to save time in the future. This is called a DNS Cache. If the website moves to a new server, or if your ISP changes its routing, one of your devices might still be looking at the old, broken address.
Technical Deep-Dive
- DNS TTL (Time to Live): Every DNS record has a timer. Until that timer expires, your device or ISP will not check for updates.
- Browser Cache: Your browser (Chrome/Edge) also keeps its own internal DNS and content cache.
- Router Cache: Many routers in Bangladesh also cache DNS queries for the entire home.
Bangladesh Context
In the local environment, this issue often presents in two specific ways:
- BDIX vs. International: Some local sites (like FTP or TV servers) are only accessible via BDIX. If your laptop is connected to a VPN, it will try to access the site via an international route and fail, while your phone (without a VPN) will work fine.
- ISP DNS Delays: Large ISPs in Bangladesh often have “sticky” DNS caches that take longer to update than Google (8.8.8.8) or Cloudflare. This is why a site might work if you manually set Google DNS on one device but fail on another using “Automatic” ISP settings.
How to Fix It
1. Flush Your DNS (Windows)
Open Command Prompt (cmd) as Admin and type:
ipconfig /flushdns
This forces Windows to forget all saved website addresses.
2. Clear Browser DNS (Chrome/Edge)
Type this into your address bar:
chrome://net-internals/#dns
Click the “Clear host cache” button.
3. Restart Your Router
Sometimes the “wrong” address is stuck in your router’s memory. Turning it off for 30 seconds and back on can force it to refresh its connection to the ISP.
FAQ
Why does the site work on 4G but not Wi-Fi?
Your mobile operator (Grameenphone/Robi) and your broadband ISP use completely different DNS servers and routes. The mobile network may have updated its records faster than your home ISP.