Download Firmware Asuswrt-Merlin build 376.48_2

Asus uses a Tomato-derived firmware called Asuswrt for its newer routers, such as the RT-N66U and RT-AC66U. This firmware is open source except for a few drivers, the binaries of which are included.

Asuswrt-merlin is a modified version of the original firmware that 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. A new version of Asuswrt-merlin was released a few days ago and its release notes look like this:

Asuswrt-Merlin – build 376.48_2

Supported devices are:

• RT-N16
• RT-N66U
• RT-AC66U
• RT-AC56U
• RT-AC68U
• RT-AC68P
• RT-AC87U

Here is a list of features that Asuswrt-merlin brings over the original firmware:

System:

• Based on 3.0.0.4.376_2769 sources (from RT-AC87U) from Asus
• Various bug fixes and optimizations
• Some components were updated to newer versions, for improved stability and security
• User scripts that run on specific events
• Cron jobs
• Ability to customize the config files used by the router services
• LED control – put your router in “Stealth Mode” by turning off all LEDs
• Entware easy setup script (alternative to Optware – the two are mutually exclusive) (not available on RT-AC56/RT-AC68/RT-AC87)
• Full SNMP support (based on experimental code from Asus)

disk sharing:

• Enable/disable the use of shorter share names
• Disk spindown after user-configurable inactivity timeout
• NFS sharing (through webui)
• Improved compatibility with 3TB+ and Advanced Format HDDs
• Allow or disable WAN access to the FTP server
• Updated Samba version (3.6.x)

Networking:

• Force acting as a Master Browser
• Act as a WINS server
• SSHD
• Allows tweaking TCP/UDP connection tracking timeouts
• CIFS client support (for mounting remote SMB share on the router)
• Layer7 iptables matching (N16/N66/AC66 only)
• User-defined options for WAN DHCP queries (required by some ISPs)
• Advanced OpenVPN client and server support (all models except RT-N16)
• Netfilter ipset module, for efficient blacklist implementation
• Configurable min/max UPNP ports
• IPSec kernel support (N16/N66/AC66 only)
• DNS-based Filtering, can be applied globally or per client

Web interface:

• Optionally save traffic stats to disk (USB or JFFS partition)
• Enhanced traffic monitoring: added monthly, as well as per IP monitoring
• Name field on the DHCP reservation list and Wireless ACL list
• System info summary page
• Wireless client IP and hostname on the Wireless Log page
• Wifi icon reports the state of both radios
• Display the Ethernet port states
• Wireless site survey

A few features that first appeared in Asuswrt-Merlin have since been integrated / enabled / re-implemented in the official firmware:

• 64K NVRAM for the RT-N66U
• HTTPS web out
• Turning WPS button into a radio on/off toggle
• Use shorter share names (folder name only)
• WakeOnLan web interface (with user-entered preset targets)
• clickable MACs on the client list for lookup in the OUI database
• Display active/tracked network connections
• VPN client connection state report
• DualWAN and Repeater mode (while it was still under development by Asus)
• OpenVPN client and server
• Configurable IPv6 firewall
• Persistent JFFS partition
• The various MAC/IP selection pulldowns will also display hostnames when possible instead of just NetBIOS names