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“Can’t resolve hostname” means Minecraft could not turn the server name you entered into an IP address. It is a name-resolution failure, not proof that the server is offline. Re-enter the address exactly, test the numeric IP:port, run nslookup, inspect your Windows DNS settings, and clear a stale cache with ipconfig /flushdns. If the numeric address works, the server is reachable and the hostname or DNS record needs attention. If neither address works, the owner must check the server, port, forwarding, and firewall.
The steps below separate a typo, a local DNS problem, and a server-side record or port problem so you do not waste time reinstalling Minecraft or changing unrelated account settings.
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What does “Can’t resolve hostname” mean in Minecraft?
Minecraft Java’s multiplayer screen displays this message when the hostname in the server address cannot be converted into an IP address. Java reports the underlying condition as an UnknownHostException; Oracle defines that exception as being thrown when “the IP address of a host could not be determined.” The failure happens before Minecraft opens a socket to the server.
A hostname can fail to resolve because it was typed incorrectly, its DNS record is missing or expired, a recently changed record has not reached your resolver yet, or your local network is returning a stale or otherwise unusable result. The message therefore identifies the lookup stage only. It does not, by itself, establish that the Minecraft process has stopped.
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Use this distinction throughout troubleshooting: first prove whether the name resolves, then prove whether the resulting address and port accept a connection. Authentication, whitelists, and game versions matter only after name resolution and connection setup have succeeded.
What is the quickest way to isolate the problem?
Run these checks in order. Each result points to a different owner of the fault.
| Check | What to do | What the result tells you |
|---|---|---|
| Address spelling | Copy the server address again, removing spaces and punctuation errors. | A corrected entry can resolve immediately if the original contained a typo. |
| Numeric address | Enter the supplied IP:port instead of the hostname. |
If it works, the server is reachable and the hostname/DNS path is the problem. |
| DNS lookup | Run nslookup your-hostname.example in Windows Command Prompt. |
You see what the configured DNS server returns for that name. |
| Local configuration | Run ipconfig /all and inspect the adapter, gateway, and DNS-server entries. |
Missing or invalid network information points to the client connection. |
| Cache refresh | Run ipconfig /flushdns, repeat nslookup, and retry Minecraft. |
A stale negative response may be removed from the Windows resolver cache. |
| Second network | Try a phone hotspot or another connection. | Success elsewhere implicates the normal network’s resolver, VPN, security software, or DNS path. |
Do not repeatedly reinstall Minecraft before these checks. Reinstallation does not repair a DNS record, a resolver response, or a server’s port forwarding.
How do I fix the error as a Minecraft player?
1. Re-enter the address exactly
Obtain the address from the server owner or the hosting control panel and copy it character for character. Remove leading or trailing spaces, accidental punctuation, and line breaks. Hostnames are not interchangeable with look-alike spellings, even when the difference is a single character.
If the owner supplied a port, enter it with a colon: hostname.example:25565 or whatever port was provided. A semicolon is not the separator Minecraft expects. Do not add a port that the owner did not give you merely because another server uses one.
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2. Test the direct IP and port
Replace the hostname with the numeric address supplied by the owner, keeping the port: 203.0.113.10:25565 is an example of the format, not an address to use. A successful connection proves that the server can be reached and narrows the fault to the name, its DNS record, or the resolver you used.
If the numeric address fails in the same way, the issue is no longer limited to hostname lookup. Continue with server-status, port, firewall, and forwarding checks instead of assuming DNS is the only cause.
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3. Run nslookup in Windows
Open Command Prompt and run:
nslookup your-hostname.exampleReplace the example with the exact hostname, without the port suffix. Microsoft explains that nslookup does not use the client’s DNS cache; it asks the DNS server configured for the computer. That makes it useful for distinguishing a cached Minecraft result from the answer currently being returned by your network’s resolver.
A successful response normally includes the DNS server used for the query and an address record for the hostname. If the response says that the name does not exist, check the spelling first. If the owner recently created or changed the address, provide the result to them and allow time for resolver caches to update.
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4. Inspect the adapter with ipconfig /all
In the same Command Prompt window, run:
ipconfig /allFind the adapter that is actually connected—Wi-Fi or Ethernet—and verify that it has an IP address, a default gateway, and DNS-server entries. Microsoft recommends this as the first client-side DNS check. An adapter with no valid address or gateway cannot reliably reach the configured resolver, regardless of what Minecraft displays.
If several adapters are listed, such as a VPN or virtual machine interface, make sure you are evaluating the connection carrying your game traffic. Disconnecting a VPN temporarily can help identify whether it is affecting the resolver path, but do not change security settings permanently without understanding the consequence.
5. Clear a stale Windows DNS cache
If an earlier lookup returned “Name does not exist,” Windows may still have that negative response cached. Run:
ipconfig /flushdnsMicrosoft documents this command for clearing the DNS resolver cache. After it completes, run nslookup again and retry the server in Minecraft. Flushing the cache does not alter worlds, saves, server files, or your Minecraft account; it only removes locally cached name-resolution results.
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6. Compare another network
Connect through a phone hotspot or another network and test the same hostname. If it resolves there but not on your normal connection, the evidence points to the original network’s DNS path, VPN, security software, or resolver cache. Send the owner the exact nslookup output and tell them which network succeeded; that is more actionable than reporting only the in-game sentence.
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If the hostname fails on every network while the numeric address works, the owner should inspect the DNS record. If both forms fail everywhere, the owner should verify that the server is running and listening on the advertised port.
Why can I join by IP but not by hostname?
A numeric address bypasses hostname lookup. When the IP works, Minecraft has already reached the server’s network endpoint, so changing authentication, whitelist, or game-version settings will not repair the hostname. The likely causes are a missing or outdated DNS record, a typo in the friendly address, or a resolver that has not received the new record yet.
Ask the owner to compare the hostname’s DNS record with the server’s current public IP. A changed public IP leaves players pointed at an old or nonexistent destination until the record is updated. While that is being corrected, continue using the direct IP:port if the owner confirms that address is current.
The reverse case is also informative. If the hostname resolves but the numeric address does not connect, the name may point to an old server, the supplied IP may be stale, or the service may be unavailable at the advertised port. The owner must check the endpoint, not just the spelling.
How does a server owner fix the hostname?
Confirm the DNS record and public IP
Check the DNS record for the exact hostname players enter and confirm that it points to the server’s current public IP. Updating a server’s public address without updating DNS produces the same player-facing error or sends players to the wrong destination. Verify the record from the owner’s DNS provider and with an independent nslookup result before telling players to retry.
Verify the advertised port
For Java servers, server-port is 25565 by default, according to the Minecraft Wiki figure quoted in ForgeWorld Gaming’s guide updated 20 October 2026. A particular host can use another port, so players must receive the actual configured value. The hostname and port are one connection target; a correct record paired with the wrong port still prevents a successful join.
Forward the port when the server is behind NAT
If the server is on a private network behind a router, forward the configured Minecraft port to the machine running the server. The forwarding rule must match the port players are given. A hostname can resolve perfectly while the connection still fails because the router sends no traffic to the server.
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Leave server-ip empty unless a specific bind is required
ForgeWorld’s current configuration guidance recommends leaving server-ip blank so the server listens on all available addresses. Binding it to an incorrect or obsolete local address can prevent the process from accepting connections even when DNS and forwarding are correct.
Check that the process and firewall permit connections
Confirm that the server is running, that it has finished starting, and that the host firewall permits the configured port. If neither the hostname nor the direct IP reaches the server, these checks take priority over DNS changes. A hostname error should not be “fixed” by changing authentication or whitelist settings, because those controls are evaluated after the address has been resolved and contacted.
Allow time after creating or changing a friendly address
New or changed DNS records are served through caches. Akliz support guidance says users can wait about 30 minutes for a newly created friendly address or connect with the ip:port shown in its Command Center. Treat 30 minutes as that provider’s approximate guidance, not a universal DNS guarantee: the actual interval depends on cached records and their expiration. Give players the direct address while the hostname catches up.
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1Clear out junk files and repair common Windows errors2Fix the driver behind crashes, sound loss and screen glitches3Repair Windows errors before they cause bigger problemsWhat is different about self-hosted and managed server setups?
The diagnostic logic is the same, but responsibility is divided differently. In a self-hosted setup, the owner controls the public IP, DNS record, router, server configuration, and firewall. A managed setup generally exposes a current connection address in its control panel, while the provider handles more of the underlying network; the owner still needs to give players the correct port and report a stale friendly address.
| Area | Self-hosted server | Managed hosting |
|---|---|---|
| Address maintenance | Owner updates DNS when the public IP changes. | Owner uses the provider’s current connection address while a friendly hostname updates. |
| Port exposure | Owner configures NAT forwarding and the host firewall for the configured server-port. |
Provider supplies the connection endpoint; the owner still distributes the correct port. |
| Recent hostname changes | Owner waits for resolver caches after changing the record. | Akliz advises waiting about 30 minutes for a newly created friendly address or using the ip:port in Command Center. |
Do not infer that a managed host is offline merely because its friendly name fails. Test the provider’s direct address first and use the provider’s status or support channel if that endpoint also fails.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.How do I distinguish hostname errors from connection errors?
The wording tells you which stage failed. Use the table below to choose the next check rather than applying every possible fix.
| Message or symptom | Stage that failed | Best next checks |
|---|---|---|
Can’t resolve hostname / UnknownHostException |
The hostname did not become an IP address. | Check spelling, run nslookup, inspect DNS, flush the Windows cache, and compare another network. |
| Connection refused | An address was reached, but the remote service rejected the socket connection. | Check that the server is running, listening on the advertised port, and not blocked by a firewall. |
| Timed out | The connection path did not complete. | After confirming the address, check routing, firewall rules, and NAT port forwarding. |
| Incompatible version, whitelist, or authentication message | Name resolution and initial connection succeeded. | Follow the server’s version, access-control, or account instructions; DNS is no longer the blocker. |
Oracle describes ConnectException as a socket connection error, typically because no process is listening at the remote address and port or the connection was refused. That is fundamentally different from an UnknownHostException, which occurs before Minecraft has an address to contact.
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What information should I send the server owner?
A concise diagnostic report lets the owner reproduce the right layer of the problem. Include:
- The exact hostname and port you entered, with personal information removed.
- Whether the numeric
IP:portworks. - The complete
nslookup hostnameresult, including the DNS server shown. - Whether
ipconfig /allshows a valid address, gateway, and DNS entries on the active adapter. - Whether
ipconfig /flushdnschanged the result. - Whether the hostname works on a phone hotspot or another network.
- The time the owner created or changed the hostname, if known.
These details tell the owner whether to correct a record, wait for caches, or investigate the server’s port and firewall. They are more useful than screenshots that show only the Minecraft error line.
Frequently Asked Questions
Can I keep using the numeric IP instead of the hostname?
Yes, provided the owner confirms that the IP and port are current. A numeric address can stop working when a self-hosted server’s public IP changes, whereas a maintained hostname can continue to point to the new address after its DNS record is updated.
What should I include when reporting this error to an administrator?
Send the exact address, whether the direct IP works, and the output of nslookup. Also state whether the hostname works on another network and whether flushing the Windows DNS cache changed anything; those comparisons identify whether the issue is local or server-wide.
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No. ipconfig /flushdns clears Windows’ cached name lookups only. It does not remove saves, alter server files, or reset Minecraft settings.
Why does a server address sometimes include a port after a colon?
The port identifies the service endpoint on the server. Java commonly uses 25565 by default, but an owner can configure another value, so enter the exact hostname:port supplied and do not replace the colon with a semicolon.
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