Can’t get to your Synology NAS? How to Fix Problems Step by Step

Synology

A lot of people have trouble connecting to a Synology NAS, but most of the time it doesn’t mean that data is lost. Network changes, IP conflicts, firewall rules, or DSM access settings are the most common causes of connectivity issues. Following a structured troubleshooting process helps quickly restore access while avoiding actions that could put data at risk.

Step 1: Check the power and the physical connections

Start with the basics. Make sure the NAS is turned on and that the power and status LEDs show that it is working normally. Look at the lights on the Ethernet ports of both the NAS and the switch or router. If there are no link lights, try a different Ethernet cable and port on the switch.

In a business setting, make sure the NAS isn’t connected to a switch port that is turned off or a VLAN that is isolated and blocks management access.

Step 2: Find out if the problem is local or remote

Before trying to fix remote access, make sure you can access the device from the same local network. If DSM works on your local network but not on a remote one, the problem is probably with the VPN, firewall rules, port forwarding, or DNS, not the NAS itself.

Local access working proves that the NAS is working and shifts the focus to setting up the network edge.

Step 3: Look up the IP address of the NAS

One of the most common reasons for losing access is when your IP address changes. The NAS might get a new IP address after the router restarts or the network changes.

Find the IP by:

Looking at the DHCP client list on the router
How to run Synology Assistant on a PC or Mac
If you can’t get to your router, use a network scanner

After you find it, go to DSM by typing https://NAS_IP:5001 or http://NAS_IP:5000 into your browser.

Step 4: Check the network on your computer

Make sure your computer is on the same subnet as the NAS. Guest Wi-Fi networks often don’t let LAN devices connect. When you’re trying to fix something, switch to the main network or use a wired connection.

Also, make sure that an active VPN client isn’t sending traffic away from the local network, which can stop devices from being found.

Step 5: Check if the network is reachable

Use ping to check if you can connect to the NAS IP address. A ping that doesn’t work usually means there are problems with routing, VLANs, or firewalls.

If the ping works but DSM doesn’t load, the network path is fine, and the problem is probably with the DSM ports, firewall rules, or service availability.

Step 6: Check the DSM ports and firewall rules

Unless you change it, DSM will use ports 5000 and 5001 by default. If DSM was hardened before, only certain IP ranges might be able to get in.

Your current network might not be allowed if the Synology firewall is on. If you can, try to get in from a trusted LAN segment. Badly set up firewall rules are a common reason why connections suddenly stop working after updates or changes to the network.

Step 7: Look at the security devices on your router and network

Even if the NAS is working fine, firewalls, security gateways, or VLAN policies can stop access to it. Make sure that management traffic is allowed between user networks and server segments in the office.

Check the settings for port forwarding, Dynamic DNS, or QuickConnect again if you want to access the internet from a distance. Replacing the router often breaks these settings.

Step 8: Check that the NAS isn’t too busy

A NAS that is doing RAID rebuilds, snapshot replication, indexing, or big backups may take a long time to respond or not load DSM at all. Wait a bit and then try again.

Check Resource Monitor to make sure that CPU, memory, and disk usage levels are normal after access is restored.

Step 9: Problems with logging in and accounts

Check for the following if DSM loads but you can’t log in:

Lockouts of accounts because of failed attempts
Changes to two-factor authentication
Accounts for admins that are disabled

Step 10: When to think there are problems with the hardware or boot

If you can’t find the NAS at all, even with cables and ports that you know work, there may be hardware or boot problems. Signs to watch out for are:

Power LED that blinks blue
NAS not starting up all the way
No lights on the network link

You can figure out if storage or hardware is stopping the NAS from starting up by doing a diskless boot test, which involves taking out the drives and turning on the NAS.

Things to Stay Away From

While troubleshooting, don’t power cycle the NAS over and over again. Forced shutdowns during volume operations or rebuilds can damage the file system and make downtime last longer.

About the Epis technology

Epis Technology helps businesses safely find and fix NAS connectivity problems by offering enterprise IT infrastructure, data protection, and Synology consulting services. The company is an expert in helping people with Synology, designing secure networks, setting up remote access, and building backups for Microsoft 365 and Google Workspace. Epis Technology helps businesses quickly regain access by fixing the root causes instead of just the symptoms. This also makes the system more resilient in the long run.