Fixing blocked devices in UniFi: How to get clients back online

Blocking a device in UniFi is easy, tap a button and they lose network access instantly. But unblocking? That’s where things get messy. Devices might reconnect but cannot reach the internet.

They might still show as blocked in the controller. You end up rebooting switches or factory-resetting access points. Frustrating when parents, guests, or even yourself can’t get back online.

This guide explains how blocking works, why unblocking often fails, and step-by-step ways to restore access. Whether it’s a phone, tablet, gaming console, or work laptop, you’ll get them back without guesswork.

Let's dive in !!

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why unblock issues happen

1. Client gets blocked at layer 2, MAC filter or firewall rule keeps them off the network.
2. Unblock doesn’t clear the block rule properly.
3. DHCP lease stays stale, device ends up with no IP or a link-local address.
4. Controller sync delays, especially on UDM/UDR hardware.
5. Switch or AP cache still blocks traffic until rebooted.
6. Firewall/ACL from Insight/history layer** remains applied ([community.ui.com], [reddit.com], [community.ui.com].

Result: device is technically “unblocked” in the UI, but can’t pass traffic.

where to find blocked devices

• In UniFi Network app or web portal, go to Clients tab.

  • Switch filter to Offline or All to see blocked devices .
  • In older UI, disable “Show only connected” and use the Blocked filter ([community.ui.com][5]).

• In Insights → Known Clients, choose Blocked filter to list all blocked MACs ([community.ui.com][6]).

You'll see them greyed-out or flagged red.

procedure to unblock properly

1. locate and select the right device entry

• Go to Clients section.
• Set filter to All or Offline (Important, blocked devices don’t show under Online).
• Identify the device by MAC, IP (if available), or name.

2. unblock via client panel

• Click the client entry.
• Hit the Unblock button.
• Confirm any prompts.

This removes the block rule. But traffic still might not pass.

3. use Insights to clear old ACL entries

• Go to Insights → Known Clients, filter for Blocked.

• In each client’s record, clear old block entries:
  • Some guides say setting the timeline back (e.g., filter “All” for last month) helps ([community.ui.com][7], [community.ui.com][1], [unihosted.com][8], [youtube.com][3]).
  • Remove stale ACL entries tied to the block event.

This resets any residual ACL.

4. reboot access point or switch

Even after unblock, AP/switch might still drop frames.

• Restart the AP via Devices panel.
• Alternatively, power cycle the switch port or entire switch to clear block cache ([reddit.com][2]).

5. have the client forget and rejoin the network

Old DHCP lease or credentials can stall the segment.

• On the client device, “Forget network”, then rejoin.
• Renew DHCP. Confirm it gets a valid IP.

If it gets a 169.254.x.x link-local address, it’s still blocked ([community.ui.com][9]).

troubleshooting tips from real users

From Ubiquiti forums and Reddit: \n> [!info]

“If you accidentally block a client... go into Client Devices, find the client… quickly press and hold down, then unblock.” ([community.ui.com][10])

“Block the device, then delete/forget from client history… Insights – Past Connections… find and click Forget.” ([reddit.com][2])

Some say toggling block/unblock multiple times helps stabilize states .

sticky block issues and workarounds

A. device appears online but no traffic

• IP pingable? Good.
• Can’t reach internet? Likely firewall.

Check block list under Clients → Blocked List and clear entries.

B. device stays on a link-local IP

Even after unblock, if it gets 169.254.x.x, DHCP server isn’t giving out leases. Either switch is still blocking DHCP traffic or controller hasn’t sent new rules. Reboot AP/switch, then reconnect the client.

C. UDM/UDR does not fully apply unblock

These devices sometimes cache block events.

Workaround: reboot the UDM’s network service, or full reboot.

D. stale history entries block reconnection

Use Insights to clear historical block records and reset timeline. That removes old ACLs ([reddit.com][2], [reddit.com][11], [community.ui.com][1]).

step-by-step recovery workflow

Let’s walk the full unblock process:

1. Identify the blocked client (Clients tab, Offline filter).
2. Unblock in client panel.
3. Go to Insights, filter Blocked → clear old ACL/history entries.
4. Reboot the AP or switch.
5. Have client forget network → reconnect → fetch DHCP.
6. Confirm IP and internet access.
7. Monitor client in controller until it appears Online normally.

If that fails:

• Toggle Block/Unblock once more.
• Check the AP logs for DHCP/ACL drop messages.
• Reboot the UDM/UDR if layer-2 block remains.
• As a last resort, manually clear from switch via SSH controller CLI.

preventing future unblock pain

• Use client groups and bandwidth limits instead of block for gentler control.
• Create guest SSID→ block policy cascades only for that SSID, main LAN stays clear.
• Track client MACs, note them in your helpdesk so you can quickly lookup.
• Test block/unblock flow monthly if you rely on it.

is block/unblock reliable?

Short answer: not yet. It works, but with edge-case glitches. UniFi should refine how blocks are enforced and cleared across all network layers, from controller to AP and switch.

Until then, manual clearing and reboots are your friend.

final thoughts

Unblocking clients in UniFi isn’t as smooth as blocking them. You’ll often need to clear stale entries in Insights, reboot network gear, and have clients forget/reconnect. But once you know all the steps, it becomes routine.

If you manage many clients or remote networks, block/unblock workflows can be handled by support teams who know this sequence. A guest VLAN with timed access or temporary bans offers smoother control than manual block/unblock. And if you need centralized support or faster controller sync, a hosted UniFi controller (like what we offer at UniHosted) helps everything happen faster and more reliably.