Asus uses a Tomato-derived firmware called Asuswrt for its routers, such as the RT-AC68 and RT-AX88. This firmware is, with the exception of a few drivers, open source, whereby the closed binaries are included. Asuswrt-Merlin, in turn, is a modified version of Asus’ original firmware. It includes bug fixes and minor improvements, but still tries to stay close to the original, so that it remains possible to add new features that Asus introduces to the code. The changelog for version 386.3 looks like this:
- First time you boot into this version, you need to either shift-reload the main index page, or clear your browser cache.
- Introducing VPN Director, which replaces the original policy routing management interface for OpenVPN clients. A bit similar to Asus’s own VPN Fusion, OpenVPN routing rules are now managed through a central web interface, and they are stored in JFFS instead of nvram, to allow creating more rules, and free up some nvram for nvram-limited devices such as the RT-AC68U. See the Wiki for more information.
- Added QR codes to the networkmap as well as the Guest Network page, to allow easily connecting a mobile device just by scanning the QR code. The generated QR code can also be saved as a file if you’d like to print it.
- Reroot OpenVPN routing handling. The firmware will now handle route creation itself rather than letting the openvpn client create/remove routes. The new implementation brings a few changes:
- “Force Internet traffic through tunnel” can now be set to “No”, “Yes (All)” or “VPN Director”.
- This setting will now override whatever setting pushed by the server regarding gateway redirection.
- The kill switch can now be used in both “Yes” and “VPN Director” routing modes
- Manually stopping a client will remove the kill switch. It will now only be applied at boot time (if client was set to start at boot), or if the tunnel is disconnected through a non-user event
- Reworked OpenVPN’s DNS Exclusive mode implementation and interaction with dnsmasq.
- Moved OpenVPN Custom settings content to JFFS, and increased max storage length from around 350 chars to 4095 chars.
- Added support for BCM50991 used for the 2.5G interface in newer RT-AX86U revisions.
- nano to 5.7.
- curl to 7.76.1.
- dnsmasq to 2.85-openssl.
- openvpn to 2.5.3.
- getdns to 1.7.0.
- stubby to 0.4.0.
- Setting an OpenVPN client’s DNS mode to Exclusive could fail to work for certain configurations
- DNS Exclusive redirections applied in Policy mode could be executed in the wrong order if you had overlapping policy rules in two separate clients.
- Clients connected to Guest Network 1 couldn’t be routed through an OpenVPN tunnel.
- Clients connected to Guest Network 1 would bypass DNSFilter rules.
- USB disks not properly unmounted on reboot on some router models.
- Missing error report on OpenVPN client connection failure
- profile.add getting used even if JFFS scripting was disabled (dave14305)
- Freedns authentication errors would not properly be reported as errors.