ASUS_RT-AX88U Merlin Tutorial (Route all Traffic trough VPN)


Updated Tutorial for the ASUS_RT-AX88U with Merlin Firmware:

1) Install Merlin on your Asus RT-AX88U:
Download the Firmware from
goto Administration -> Firmware and Upload the current Merlin Firmware (RT-AX88U_384.19_0_cferom_ubi.w)

2) WAN Settings:
Connect to DNS Server automatically -> NO

DNS Server1 -> x.x.x.x
DNS Server2 -> x.x.x.x
(You can use PP/Google/Cloudflare DNS)

3) IPv6:
Connection type -> Native
Enable Router Advertisement -> Disable

4) VPN -> VPN Client:
Import .ovpn file -> Upload the Server.ovpn
(Download from
and wait 2-3 sec. till the Site gets refreshed, now you can see the PP Server IP under "Server Address and Port".

Automatic start at boot time -> Yes
Description -> Servername
Accept DNS Configuration -> Exclusive
Username -> xxx
Password -> xxx
Cipher Negotiation -> Enable (with fallback)
Force Internet traffic through tunnel -> Policy Rules (strict)
Block routed clients if tunnel goes down -> Yes

Rules for routing client traffic through the tunnel (Maximum : 100):
select under "Source IP" your connected PC/Receiver/Laptop/Nas and add it with "+" on the right side,
if your PC/Receiver/Laptop/Nas is not shown up in the dropdown then its not connected to the Asus Router or offline.

5/1) Firewall -> General:
Enable DoS protection -> Yes

5/2) Firewall -> Network Services Filter:
Enable Network Services Filter -> Yes
Filter table type -> White List

6) goto VPN -> VPN Client -> Service state and start the VPN Connection
(if you get a Connection Error, make sure you have saved all and do a restart).

7) Test your DNS/IP for leaks

***Extras and Bug Fixes***

- JFFS (RAM) Error after upgrade from Merlin 384.18 or Original Asus Firmware to 384.19 fix:

Restart the Asus Router 1-2 times fixed this for most users.
(if not working follow the steps below first and then try the restarts)

Flash the current Official Asus Firmware from the Asus Support Website
- Power Off
- Hold WPS (Next to Power Button on top)
- Power On (while keeping the WPS Button still pressed)
- The Power LED should go out after some sec.
- Now release the WPS Button and turn the Asus Router ON again
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