# ESP32 hostname.local does not open: mDNS problems

> Fix an ESP32 mDNS name that does not resolve: call MDNS.begin, use the IP address as a test, and know that some systems handle .local poorly.

Canonical: https://roboticsengineering.in/fix/esp32-mdns-hostname-local-not-resolving/ | Published: 2026-11-03 | Updated: 2026-11-03

**Test with the IP address first. If that works, the problem is only the name lookup.**

## What the message means

mDNS lets devices find each other by a name ending in .local. Support differs between systems, and some networks block it.

## Fix it in this order

1. Call MDNS.begin(“name”) after Wi-Fi connects and check that it returns true.
2. Open http://name.local/ and, if that fails, open the IP address to confirm the server works.
3. Check that your computer supports mDNS. Install the service software on older Windows if needed.
4. Some routers and guest networks block multicast traffic.
5. Use a fixed IP address or a router reservation as a simple alternative.

## If you see this, do this

| You see | Do this |
| --- | --- |
| IP works, name does not | mDNS support or blocked multicast. |
| Neither works | See the web server page. |

## Related

[web server not reachable](https://roboticsengineering.in/fix/esp32-web-server-not-reachable-from-browser/), [Wi-Fi will not connect](https://roboticsengineering.in/fix/esp32-wifi-wont-connect/).

Last reviewed: November 2026. These are the usual causes and the order that finds them fastest. Test on your own board; clones and cables differ.