If you’ve been locked out of your Synology NAS — or a specific IP address has been blocked by its security system — you’re not alone. Synology’s built-in security features are aggressive by design, and it’s surprisingly easy for legitimate users or home devices to end up on the blocked list. This guide walks you through exactly how to unblock an IP address on Synology NAS, whether you’re using the Auto Block feature or the firewall rules panel.
Why Does Synology NAS Block IP Addresses?
Synology NAS devices run DiskStation Manager (DSM), which includes a feature called Auto Block. This automatically blocks any IP address that fails to log in too many times within a set time window. It’s a great defense against brute-force attacks, but it can occasionally catch real users — especially if you mistype a password a few times from your phone, or a connected app uses stale credentials.
Beyond Auto Block, the DSM Firewall can also explicitly deny access from specific IP ranges. If your IP was manually added to a deny rule, that’s a separate fix from the Auto Block list.
How to Unblock an IP Address Using Auto Block (DSM 7)
This is the most common reason an IP gets blocked. Here’s how to remove it:
- Log in to DSM from a device that isn’t blocked (another computer or phone on the same network).
- Go to Control Panel → Security → Auto Block.
- Click the Allow/Block List button.
- Switch to the Block List tab.
- Find the IP address you want to unblock, select it, and click Delete.
- Click OK to confirm.
That’s it — the IP is immediately removed from the block list and can connect again. If you’re not sure which IP was blocked, check the Log Center in DSM for recent failed login attempts. It will show you the exact IP that triggered the block.
How to Unblock an IP via the Synology Firewall
If Auto Block isn’t the culprit, the firewall might be the issue. To check:
- Go to Control Panel → Security → Firewall.
- Click Edit Rules next to the active firewall profile.
- Look for any Deny rules that match the IP address in question.
- Select the rule and click Delete, or change it to Allow.
- Save your changes and test the connection.
Firewall rules are processed top to bottom, so if a Deny rule appears before an Allow rule for the same IP, the Deny will win. Make sure your Allow rules sit above any broad Deny rules for the relevant IP range.
What If You’re Completely Locked Out?
If every device you own has been blocked and you can’t access DSM at all, you have a couple of options:
- Connect directly via LAN: Plug an ethernet cable from your computer directly into the NAS. Local connections on the same subnet are typically not subject to Auto Block.
- Reset network settings: As a last resort, you can use the physical reset button on the NAS to reset network settings without wiping your data. Check your specific model’s documentation for the exact procedure.
- Use Synology Assistant: The desktop app can sometimes detect and connect to a NAS on the local network even when web access is blocked.
Preventing IP Blocks in the Future
Once you’ve sorted out the immediate problem, it’s worth taking a few minutes to reduce the chance of it happening again. A few practical steps:
- Whitelist your home IP range in Auto Block so your own devices are never auto-blocked.
- Use a VPN to access your NAS remotely instead of exposing it directly to the internet. This dramatically reduces the number of brute-force attempts your NAS will see. A reliable option is NordVPN (try it free for 30 days), which works well for securing remote connections to home servers.
- Enable two-factor authentication (2FA) in DSM — even if someone knows your password, they can’t log in without the second factor.
- Reduce the Auto Block threshold to something reasonable, like 5 failed attempts in 5 minutes, to balance security with usability.
If you’re managing IPTV streams through your NAS and running into connectivity issues, it may also be worth reviewing your M3U playlist checker setup to rule out network-side problems that could look like IP blocks.
Should You Keep Auto Block Enabled?
Yes — absolutely. Auto Block is one of the simplest and most effective defenses against unauthorized access, especially if your NAS is accessible from the internet. The occasional false positive is a minor inconvenience compared to the protection it provides. The fix takes less than two minutes once you know where to look.
If you’re running services that connect to your NAS from multiple external IPs — such as remote workers, M3U file streaming setups, or cloud sync tools — consider setting a more lenient Auto Block threshold or whitelisting those IP ranges explicitly rather than disabling the feature entirely.
Get Back In and Stay Secure
Unblocking an IP on Synology NAS is straightforward once you know which tool caused the block — Auto Block or the Firewall. The two-minute fix above will get you back in immediately. From there, whitelisting your trusted IPs and routing remote access through a VPN will save you from dealing with this again. A well-configured Synology NAS is one of the most reliable bits of home infrastructure you can run — it just needs a little tuning to stay out of your way.
Photo by Taylor Vick on Unsplash