NAS Hostname Fails but IP Works – DNS Fix

Yeah, that's annoying. You type the NAS hostname and get nothing, but the IP works fine. You've probably been poking at SMB settings or restarting services. Stop. The fix is almost always a DNS or naming resolution issue, not a share problem.

The Quick Fix

1. Disable and re-enable network discovery on Windows 11:
   Control Panel > Network and Sharing Center > Advanced sharing settings – turn off network discovery, apply, turn it back on. This forces Windows to re-register its NetBIOS and LLMNR entries.
2. Flush DNS and reset the Windows socket cache:
   Open cmd as admin and run:

   ipconfig /flushdns
   nbtstat -R
   nbtstat -RR
   netsh int ip reset
   netsh winsock reset

   Reboot after.
3. Append the NAS hostname with local network suffix:
   Try nasname.local instead of just nasname. If that works, the fix is permanent: edit C:\Windows\System32\drivers\etc\hosts and add a line like:

   192.168.1.100  nasname

   Replace IP with your NAS's actual static IP.

That's it for 80% of cases. The rest is about why this even happens.

Why This Works

What's actually happening here is that your NAS is announcing itself via mDNS (Bonjour on macOS, Avahi on Linux, or LLMNR on Windows) but your router's DNS server doesn't know about it. Modern Windows prefers DNS over NetBIOS since Vista, and if the router doesn't have a DNS entry for the NAS hostname, Windows falls back to link-local multicast – which often fails on VLANs, guest networks, or when the NAS is on a different subnet.

Step 1 resets the Windows network profile, which clears stale cache entries. Step 2 purges the DNS resolver cache and resets the TCP/IP stack – old WINS/NetBIOS mappings that point to a wrong IP get wiped. Step 3 forces a static mapping via the hosts file, which Windows checks before any other name resolution method. The .local suffix trick works because Windows 10 and 11 have a bug where they sometimes don't append the default search suffix unless you specify it explicitly.

The reason step 3 is the permanent fix: the hosts file bypasses DNS entirely. Your NAS should have a static IP anyway – dynamic DHCP leases break hostname resolution when the IP changes mid-session.

Less Common Variations

1. macOS – Bonjour not resolving

On macOS, open Terminal and run dns-sd -G v4 nasname.local. If that fails, it's a Bonjour registry problem. Restart the mDNSResponder daemon:

sudo killall -HUP mDNSResponder

2. Linux (Ubuntu/Debian) – Avahi not seeing NAS

Install avahi-daemon and avahi-utils. Then run avahi-browse -a -t to list all mDNS services on the network. If the NAS doesn't appear, your router might be blocking mDNS packets (common on UniFi or pfSense). Fix: create a static DNS entry on the router pointing nasname to the NAS IP. On pfSense, go to Services > DNS Resolver > Host Overrides.

3. Windows 11 – Network discovery turns off automatically

Some users see the NAS in File Explorer but cannot open it – they get a login prompt that fails even with correct credentials. This is a credential manager conflict. Open Control Panel > Credential Manager > Windows Credentials, remove any entries for nasname or the NAS IP. Reboot. Then map the drive fresh using the hostname.

Prevention

The root cause is that consumer routers don't register device hostnames in their DNS by default. You have three good options:

• Static DNS entry on router – Most routers (Asus, TP-Link, Ubiquiti) let you create a fixed hostname mapping in LAN settings. Do this. It's 30 seconds and solves it for every device on the network.
• Enable LLMNR or NetBIOS over TCP/IP – On Windows, go to Network Connections > Properties > Internet Protocol Version 4 (TCP/IPv4) > Advanced > WINS, set NetBIOS to Default or Enable. This works but is less reliable than DNS.
• Set a static IP on the NAS – Do this in the NAS's web interface. A dynamic IP that changes kills hostname resolution until you flush everything. Static IP + router DNS entry = zero issues.

One last thing: if you're on a corporate network with group policies, your IT might have disabled LLMNR and mDNS. In that case, only a DNS entry works. Talk to your network admin, or just use the IP directly – it's not that hard to remember 192.168.1.100.