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Asus RT-AC66U Dual-Band 802.11ac Gigabit Router review


  • Very impressive range
  • Excellent performance at 5GHz 11n
  • Plenty of advanced features on board
  • Business-class capabilities


  • Somewhat sluggish interface
  • Lost Internet connectivity a few times

Asus has introduced its pre-draft 802.11ac router, the RT-AC66U. It’s the only pre-draft 11ac router thus far to utilise external antennas, which is a plus in terms of range, and the RT-AC66U sustained a better throughput at distance compared to other pre-draft 11ac routers we’ve seen.

This powerful router also offers one of the most well-designed user interfaces among the current crop of 11ac routers. The RT-AC66U is not without a few quirks, although these are mainly restricted to the software. Despite this, the excellent throughput and range, plus advanced features often lacking in consumer-grade routers, are sure to endear this device to more hardcore wireless networking geeks and small business users.


The RT-AC66U is a beauty of a router, despite the three unwieldy looking external antennas. The casing bears a decorative diamond-shaped pattern, and the Asus branding rendered in classy painted gold on the top. Also on the top near the edge are nine tiny LEDs displaying connection status for the WAN and LAN ports, power, each wireless band, and USB device connections. When a connection is active and stable, the LEDs shine a solid blue.

The rear panel has four Gigabit LAN ports and a WAN port, along with two USB 2.0 ports that can support not only external USB drives, but printers and 3G/4G mobile broadband devices that can be used as connection failsafes.

This dual-band router supports up to 450 Mbps at 2.4GHz and up to 1300 Mbps on the 5GHz band. The RT-AC66U uses a Broadcom wireless controller.


The RT-AC66U employs what I like to call a traditional router setup. Increasingly, consumer routers such as the Cisco Linksys EA6500 are tailored to be set up by those with little to no technical experience. Many of these super-easy-to-setup routers can also be set up wirelessly.

Not so with the RT-AC66U. This router is setup using a wired connection from a computer to one of the LAN ports on the router. The easiest way to get the router setup is to follow the directions on the accompanying Quick Start Guide. The guide shows how to best position the router for optimal signal strength, how to mount it on the stand that also ships with the router (the RT-AC66U's documentation states that operating the router in an upright position on its stand yields the best wireless signal), and how to connect the cables.

Once a computer is connected to the LAN port and the router is on, users can open a browser and the router's setup page is automatically brought up. The Quick Internet Setup Wizard on the supplied CD walks you through the setup process.

The setup steps are pretty routine. First, you set a password to access the router's interface under the admin account. The router then detects the WAN connection (in my case my DSL connection was correctly identified). Setup concludes with assigning a password for each wireless band. The interface has a nice feature in which you click a checkbox to copy over settings for the 2.4GHz band – such as encryption level, SSID, and so forth – to the 5GHz band, saving some typing time.

There isn't a lot of configuration needed if you don't want to bother with it all, because the router automatically sets the SSIDs and the encryption level to WPA2 Personal with AES encryption.

So getting the RT-AC66U going was virtually a pain-free experience. I encountered one quirk performing a firmware update. The router software instantly detected a newer version of firmware available, and I followed the steps to download and apply the new version.

The router was shipped to me with firmware version The interface, after detecting a newer version of the software, correctly displayed the current version, but identified the new version as "undefined.undefined.undefined_260,” as if it was having issues correctly identifying the new version of the firmware (which is

Despite the weird display of the new firmware version, I went ahead with the upgrade. A status bar appeared on-screen along with the message to wait about three minutes for the update to complete. I never saw any progress on the status bar. After about three minutes, the page remained the same with no progress in the bar, except at this point, I received a prompt to log back into the router.

When I logged back in, the screen was still in the firmware upgrade area of the interface except now I had a message: "Router's current firmware is the latest version." So I had no idea if the firmware upgrade took place or not.

However, as it happened, the update had been applied. Going into the router's status page I noticed the firmware being reported as the latest version. But still, the automatic firmware upgrade process was messy. On a second RT-AC66U router that Asus sent to use as a bridge to test 11ac, I performed the upgrade manually without incident. Even so, it's convenient to have the router being able to detect and perform the firmware upgrade automatically, so hopefully this small gripe is something that will get worked out in a future update.

I also noticed some sluggishness switching through different pages in the router’s interface whether I was accessing via Internet Explorer or Firefox. There was also an issue once or twice where devices connected to the router could not access the Internet. The issue was only resolved with a router reboot. It seems another firmware update may be in order.

Interface and consumer features

The beauty of the physical design of the RT-AC66U extends to the interface. It's one of the more stylish router management interfaces out there. The design is clean, easy to work within, and has a futuristic look that almost seems like some sort of control scheme for a video game.

The home page of the interface displays just about all the information that the typical router user may want to know such as which devices are accessing the network, WAN status, and wireless network details. The network map showing the devices connected displays the device name and IP address. The map also correctly listed an older Android phone I connected to the 2.4GHz network.

Feature such as parental controls, QoS, firewall, and security are all included. The parental control isn't as extensive as I've seen in other routers such as Netgear which uses a cloud-based service to provide fairly granular content control. In this Asus router, the parental controls only really let you set time limits on specific devices to control their Internet access.

However, the firewall properties do allow for the setting up of content blocking by keyword or URL. I entered "Facebook" as a keyword and was unable to click any link containing that word. Users can also select to block networking services such as Telnet.

The interface also includes some management features for connected USB devices. For accessing data stored on connected USB drives, users can download the AiCloud app for iOS or Android devices. Accessing that data remotely with AiCloud takes some configuration, as either port forwarding or setting up a DMZ for the external drive is required.

Business-class features

The RT-AC66U can function as a small business router because it has several advanced capabilities that are not featured in all consumer routers. First, you can implement up to six guest networks: Three on the 2.4GHz band and three on 5GHz.

Also, the Asus router has a full built-in VPN server, not just VPN passthrough support as many consumer routers offer. There are also several advanced options which can be tweaked including AP isolation, setting the multicast rate, enabling jumbo frames for the LAN, disabling the HW accelerator, and more options that are typically in access points for the SMB. The RT-AC66U also offers robust IPv6 support.


The RT-AC66U’s performance varied from very good to excellent, depending on the mode used. At 5GHz in 802.11n mode, the Asus router's performance was the second fastest we’ve ever seen, only trailing the Cisco Linksys EA6500, with the RT-AC66U averaging 174 Mbps at a distance of 10 feet.

In 11ac mode, throughput was on par with the Cisco Linksys – which was no surprise, since both routers use the Broadcom chipset. At a distance of about 15 feet in 11ac mode, the Asus router managed a respectable 129 Mbps.

2.4GHz mixed mode saw this Asus router averaging 71 Mbps at 10 feet, and it performed about the same in 2.4GHz n-only mode. Mind you, 70 Mbps in our testing environment in 2.4GHz – an absolutely crowded band – is very good throughput.

Where the Asus outdid other 11ac routers is in terms of range. I test all pre-draft 11ac routers at a distance of 50 feet which, in the testing lab, is a very weak or dead spot for most 802.11n routers. Since 11ac is about speed and range on 5GHz I test at this distance on these 11ac routers. The Asus router maintained the best throughput at 50 feet – 77 Mbps, better than any router I've tested without using a wireless extender. It would seem the external antennas most vendors have eschewed certainly helps the Asus router when it comes to range.


The Asus RT-AC66U is on a par with the excellent Cisco Linksys EA6500 11ac router. However, the two routers are best suited for two different types of customers. Those who may not be as comfortable setting up network devices, and would benefit from an almost automated setup process – and who don't need a lot of extras in terms of features – would be best served by the Linksys device.

Those wanting a true VPN server, robust IPv6, and granular control over the wireless signal will find the Asus RT-AC66U a delight. For this reason, the RT-AC66U receives our Best Buy award, and it’s a great choice as a small business (SOHO) router, or for the more technical home user.


Manufacturer and Product

Asus RT-AC66U Dual-Band 802.11ac Gigabit Router

Networking Options

802.11b/g/n, 802.11ac draft

Access Control Lists based on MAC Addresses




Quality of Service



WEP, WPA, WPA2, WPS (Wi-Fi Protected Setup), WPA2-Enterprise