--- title: How to resolve IP blocking issues description: Learn to troubleshoot IP blocking issues for both shared and personal networks. url: /kb/guide/how-to-resolve-ip-blocking-issues canonical_url: "https://vercel.com/kb/guide/how-to-resolve-ip-blocking-issues" published: 2026-03-19 last_updated: 2026-08-10 authors: Pauline Narvas, Anders Morley-Hagström related: - /kb/guide/how-to-fix-a-domain-suspended-by-serverhold-or-clienthold - /docs/firewall - /docs/firewall/vercel-waf/ip-blocking - /docs/bot-protection - /docs/vercel-firewall/vercel-waf/custom-rules - /docs/domains/troubleshooting install_vercel_plugin: npx plugins add vercel/vercel-plugin --- If you can't access Vercel-hosted sites and debugging tools show your IP address is blocked, the cause is most likely your ISP or network policy, not Vercel. You might experience: - **Inability to load Vercel-hosted sites**: Pages time out or return connection errors - **Blocked IP addresses**: Debugging tools show your IP is being rejected - **Multiple users affected**: Others on the same network experience the same issue ## Common causes - **ISP throttling**: Some ISPs block or throttle access to certain websites during peak usage hours. With ISPs like [Spectrum](https://www.spectrum.net/support/forms/verify_url_security) or [Xfinity](https://spa.xfinity.com/check_url_status), you can check blocks directly. For other ISPs, you might need to reach out to their support. - **Network policies**: Universities, offices, and other shared networks often have firewall rules that inadvertently block certain sites. The quickest way to resolve these types of issues is to talk to your IT team. - **Issues with the domain:** If your domain has been blocked due to non-compliance, it will stop working for all users. You can read more about this in our article about “[How to fix a domain suspended by serverHold or clientHold](https://vercel.com/kb/guide/how-to-fix-a-domain-suspended-by-serverhold-or-clienthold)” ## Resolve the issue on a shared network If you're on a university, office, or other managed network, contact your network administrator or IT department. Provide them with any debugging information, including the blocked IP address and the domains you're trying to reach: `vercel.com` or `vercel.app` , and any custom domain. ## Is it the network, or the site's firewall? These two causes look similar but are fixed in completely different places. Check which one you have first. | Symptom | Likely cause | Where to fix it | | ----------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------- | | Request times out, no HTTP response at all | Network-level blocking on the path to Vercel | Your network or ISP | | You get an HTTP `403` response, a challenge page, or a block page | The site's [Vercel Firewall](https://vercel.com/docs/firewall), [IP blocking](https://vercel.com/docs/firewall/vercel-waf/ip-blocking), or [Bot Management](https://vercel.com/docs/bot-protection) rules | The site owner's project settings | An HTTP response means the request reached Vercel, so the network isn't the problem. If you're the site owner and want to check whether your own rules are responsible, review your firewall rules and IP block list in the [dashboard](https://vercel.com/docs/vercel-firewall/vercel-waf/custom-rules). ## General troubleshooting steps If the issue persists, try the following: 1\. **Test from a different network.** Try mobile data, a hotspot, or a VPN. If the site loads, the problem is your original network, which confirms the direction of the fix. 2\. **Confirm DNS is resolving.** Run `dig` [`example.com`](http://example.com) `+short` or check the domain at [whois.vercel.support](https://whois.vercel.support). If it returns nothing, the issue is DNS rather than IP blocking - see [Troubleshooting domains](https://vercel.com/docs/domains/troubleshooting). 3**. Check whether it's only the custom domain.** If the project's vercel.app URL loads, but the custom domain times out; only the domain's specific address is being blocked or misrouted. This indicates a block on your side or an issue with the domain, such as a [clientHold/serverHold](https://vercel.com/kb/guide/how-to-fix-a-domain-suspended-by-serverhold-or-clienthold). 4\. **Check your router's block list**: Look up the manufacturer documentation on how to check this, but it will usually be located at 192.168.1.1 or similar and under a “Firewall” tab. 5\. **Flush your DNS cache**: - **macOS**: Run `sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder` in Terminal - **Windows**: Run `ipconfig /flushdns` in Command Prompt - **Linux**: Run `sudo systemd-resolve --flush-caches` in your terminal 5\. **Reset network settings**: Restore your network configuration to defaults through your operating system's network settings ## Get additional help If you've completed the steps above and the issue continues, please reach out to our support team and make sure you provide the output of the debug script available at [https://debug.vercel-support.app/](https://debug.vercel-support.app/)