Asus Blue Cave Router Review: A Hole Lot of Wi-Fi

The Asus Blue Cave has the usual amount of ports plus a very usual hole right in the middle.
The Asus Blue Cave has the usual amount of ports plus a peculiar hole right in the middle.

There’s a big, intriguing blue hole right in the middle of the Asus Blue Cave that catches your full attention the first time you lay eyes on it. But that’s all there is to it. I was a bit disappointed when Asus told me there was no deep meaning about this hole. It’s just a conversation — or review — starter. There you have it!

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As a Wi-Fi router, however, there’s nothing blue about the Blue Cave. It’s one of the fastest routers I’ve tested with tons of useful features. It also has a surprisingly long Wi-Fi range considering its compact footprint. If you have a medium-size house of around 2,000ft² (180m²), you’ll find the Blue Cave an excellent buy.

Dong’s note: I originally published this review on May 10, 2018, and updated it on July 12 with additional information on the new AiMesh feature.

Asus Blue Cave

8.4

Performance

8.5/10

Features

8.0/10

Design and Setup

8.5/10

Value

8.5/10

Pros

  • Excellent performance
  • Generous feature set including the ability to protect the home network against online threats
  • Unique design with small footprint
  • Easy to setup and use

Cons

  • Not as feature rich as other Asus routers
  • Unable to block secure websites
  • USB-based storage’s performance could be faster

Asus Blue Cave: A weird name in an unconventional design

At a glance, the Blue Cave is like no other router you’ve seen. It’s a square piece of hardware with a big hole — big enough to put a golf ball through — right in the middle. When the router is on, the entire area surrounding the hole glows different shades of blue and remains that way until you choose to dim or turn it off via the router’s web interface.

(By the way, you can only turn the light off when using the Blue Cave as a router. When used as an AiMesh node, the router’s web interface is not user-accessible, and you, therefore, will have to live with that light being on at all times. That’s not necessarily a terrible thing unless it’s your bedroom.)

I’ve asked Asus many times about the idea behind this design since the router’s announcement. At first, the company said it had something to do with the positioning of the internal antennas, but now, it turned out; there’s nothing to it. It’s just for the look, and that works! You sure will remember the Blue Cave once you’ve seen it.

So, I like the design. While you can’t wall-mount it, you can place it on almost any surface thanks to its small footprint. The router has a nice heft and stays put; it doesn’t topple easily. Its exciting look means you won’t need to hide it, either. By the way, I dig the name, too. Blue Cave. Slightly weird for a networking device, but easy to remember.

On the back, the router has the usual ports and buttons: four Gigabit LAN ports, one Gigabit WAN (Internet) port, one USB 3.0 port, a power button, a reset button, and a WPS button. It’s just like any other Asus router, such as the Asus RT-AC86U, which has a terribly generic name.

Powerful hardware

The Asus Blue Cave has powerful hardware. It’s an AC2600 dual-band 4×4 router with the top speed on the 5GHz band of up to 1733Mbps and on the 2.4GHz, up to 600Mbps (or 800Mbps for TurboQAM-ready clients).

The router sports 512MB of RAM, 128MB of flash memory, and uses an Intel (Lantiq) dual-core 1.6 GHz CPU. Lantiq originally was a company focusing on smart-home devices until Intel acquired it in 2015. But the Blue Cave doesn’t have a lot of smart-home features, just the support for Amazon Alexa & IFTTT. Both have been available in most other Asus routers, so this isn’t a novelty.

You’ll first need to activate it with Alexa before you can use your voice, but I wouldn’t do that. Among other things, anyone, including those on TV, can easily mess you up by saying a command that, for example, causes your router to restart. Voice commands and networking don’t mix.

Asus Blue Cave’s hardware specifications

Asus Blue Cave’s extra photos

The mysterious blue hole of the Asus Blue Cave that lights up when the router is in use.

It generally takes days to thoroughly test a Wi-Fi routers.
The Asus Blue Cave comes with the usual amount of network ports

The router looks quite good, even from the backside.

The Blue Cave is a compact router with all the usual ports on the back.
The Blue Cave is relatively compact, thanks to the internal-antenna design.

From one side, the Blue Cave looks quite mundane.

The top view carries nothing special either.

But from the front, the router can be intriguing.

Even the box of the Asus Blue Cave looks cool.

Easy setup

Setting up the Blue Cave is like that of any router with a web interface and is the same as the RT-AC86U.

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First, you connect the WAN (Internet) port to your modem or your gateway. Then hook a computer to one of its LAN ports using a network cable, then open a web browser. You’ll automatically get to its web interface, where you’ll find a wizard that walks you through the process step by step. Alternatively, you can also use the Asus Router app (for iOS and Android) for this job.

(Note: The Blue Cave doesn’t support universal setting restoration. In other words, you can’t restore it with the setting backup file of another Asus router, but only of another Blue Cave unit.)

After the setup process, you can continue to use the app for the on-going management of the router. I prefer using the router’s web interface, however, since it has access to all of the router’s features and settings. You can always get to the interface by pointing a browser of a contested computer to router.asus.com (or the router’s default IP, which is 192.168.50.1).

Here you’ll find all of its settings and a ton of useful features.

Familiar feature set

The Blue Cave shares the same feature set as that of the RT-AC86u, minus the Game Boost — this is not a router for hardcore gamers. That said, if you’ve used any Asus router before, you’ll feel right at home.

Asus Blue Cave’s features via screenshots

The Asus Blue Cave's web interface is similar to that of most Asus routers and offers access to many useful features..
The Asus Blue Cave’s web interface is similar to that of most Asus routers and offers access to many useful features, including Network Protection as seen here.
The Asus Blue Cave can work as a VPN server.

When hosting an external drive, the Blue Cave can offer all sorts of network storage features.

The Traffic Analyzer can come in handy.

Adaptive QoS helps the Asus Blue Cave prioritize the Internet connection.

The Asus Blue Cave has a decent Parental Control feature.

You can use voice command with the Asus Blue Cave.

The router has all the settings you would need for your network. It can work as a VPN server (or a client) and has a powerful AiProtection online security feature.

Powered by TrendMicro, AiProtection scans your network and the online connection in real-time to keep our entire system safe. While there’s no total protection, in my experience, AiProtection works quite effectively. Best of all, it’s free.

Via its USB port, the router can do all you can imagine with a plugged-in external hard drive. Apart from data sharing, media streaming, you can even set the Blue Cave to work as a Time Machine backup server. By the way, if you decide to use Time Machine backup, make sure you set a backup limit if you want to use the storage for other purposes.

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Other than that, the router also has a cool Traffic Manager feature that includes an easy-to-use QoS for Internet prioritization, and a Web History that keep tap of connected clients’ online activities.

Generally, all router-related features a home user can think of, the Blue Cave has it. OK, maybe not all since the router does have some imperfections.

Minor shortcomings

At launch, the Blue Cave didn’t support MU-MIMO as well as Asus’ AiMesh. Later on, both were available via firmware updates

Like most other routers from Asus, the Bue Cave can’t block secure websites, those with https in their web address. Since most sites now use https, the router’s web filtering feature is rather useless.

Note that, like other Asus routers, the Blue Cave has a Parental Controls feature, which is part of AiProtection, that can block sites based on categories. But it doesn’t allow you to pick and choose individual websites to block.

Unlike many other routers from Asus, the Blue Cave doesn’t support Dual-WAN, where you can turn one of its LAN ports into a second WAN port, enabling you to use two Internet connections at a time. This omission is not a huge deal, however, since most of us don’t have a secondary broadband connection.

Though not exactly smaller, the Blue Cave has smaller footprint than the RT-AC86U thanks to its internal antennas.
Though not exactly smaller, the Blue Cave has a smaller footprint than the RT-AC86U thanks to its internal antennas.

Asus Blue Cave: Fast performance

As a Wi-Fi router, the Asus Blue Cave did well in my testing, being the top three on the 5GHz band. It’s faster than many routers of bulkier physical sizes.

On the 2.4 GHz band, it did even better, being the fastest I’ve seen in close range. At some 40 feet (18m) away, it was still among the top three.

The Asus Blue Cave also had an excellent range, about the same as the RT-AC86u, which is larger and has higher hardware specs. Generally, you can expect the effective range to be 150ft (46m) and even further. Note that Wi-Fi signals change depending on the environment, so your mileage might vary.

When coupled with a USB portable drive, via a Gigabit connection, the Blue Cave’s network storage speed capped at 27 megabytes per second for both writing and reading. While this is fast enough to do some light data sharing, it’s not fast enough for big tasks.

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That said, if you want to get serious with network backups and media streaming, get a dedicated NAS server, like the Synology DS218+ instead.

Conclusion

The Asus Blue Cave is an exciting Wi-Fi router that works well for anyone living in a medium home or smaller. And if you happen to like its quirky-looking object (I do!), this is the router for you.

Considering the recently-added support for AiMesh, the Blue Cave is an easy recommendation for anyone wanting a robust home Wi-Fi network with the option to scale it up to a Wi-Fi mesh system at a later time.

38 thoughts on “Asus Blue Cave Router Review: A Hole Lot of Wi-Fi”

  1. Is the Blue Cave still a good option in 2020? I have a Linksys WRT1900ACS that doesn’t reach my bedroom in my new 800sq ft home (moved from an apartment). Considering buying one Blue Cave now, and might test a second with AiMesh if needed – is that better than an Eero or other mesh wifi? Thanks.

    Reply
  2. I tried the web UI as well. The connected 2.4 Guest devices do not show up. When I setup the Lyra Trio instead, I can see them online using either the Web UI or app

    Reply
    • Probably a glitch somewhere. Generally, I don’t trust most routers when it comes to seeing connected clients, at least the timing of it. It’s a bit more complicated than you might think. Some routers, including Asus ones, don’t even show connected clients at all. This, by the way, also depends on the clients, as well as how you set up the DHCP server.

      Reply
  3. already updated to latest. one more thing, all the devices using Guest network shows up as Offline in the Asus Router app but they are actually online, just not showing up as online in the app or web ui

    Reply
    • Don’t trust the mobile app. I’ve always used the web interface. You can use the interface on your mobile device, too, and it’s kinda a mobile app.

      Reply
  4. I just bought this Blue Cave yesterday. Set it with nothing fancy, just added a Guest network for both 2.4 and 5Ghz. Everything else is default. After a couple of hours, the 2.4Ghz band goes missing and the 5Ghz, althought still showing but you cant get on the internet. Off and On fixes it. I reset the router and setup again. Again the same thing happened. Altogether 5 times yesterday. I also noticed that it says it is disconnected from the Internet but it can still surf to any websites. Today I went back to the store to exchange another unit. Brought it back and its still happening. The difference this time around is it doesnt say its disconnected and my 5Ghz still can work. The 2.4 is missing both the main and guest. I dont know what else to do. I Off/On it and the band comes back on but my device cant login, says wrong password. Any suggestion is fully appreciated 🙁 Oh, I switch back to my old router a TPLink Ac1200 and it works fine.

    Reply
  5. I have been using 3 RT-AC68U for AiMesh, but nodes are disconnected from the main router often.
    I just replaced the main 68U with Blue Cave, but then I’m having issue with manually assigned IPs for DHCP.
    Apparently, devices connected to the nodes will have a 2nd MAC address (for routing purpose? the first 3 parts of MAC are the same for all devices connected to the same node) and Blue Cave’s DHCP server seems not assigning the IPs set in the DHCP table associated with the original MAC, but instead doing dynamic allocation of a new IP. It’s causing the devices sometimes use dynamic IP but sometimes jump to assigned IP. Any services requires the assigned IP, like my NVR, cannot connect to those devices reliably.

    Anyone have the same issues? I didn’t have this DHCP issue when using RT-AC68U has main router.

    Reply
  6. Hi Dong Ngo, I have a 500Mbps line and living in a single level 1900 sq ft apartment with lots of concrete walls. I’m getting decent 5Ghz but very poor 2.4Ghz in my bedroom. I got lots of IoT devices connected to my 2.4Ghz Guest Network. Should I get a Blue Cave and 2 units of Lyra Trio or should I not mess with AiMesh and just buy the 3 pieces of Lyra Trio. For 2.4Ghz Im getting around 50Mbps and 5Ghz band Im getting around 280Mbps (near to router) Your advice is greatly appreciated sir.

    Reply
    • Peter, 2.4Ghz is ALWAYS terrible, there’s no way around it. If you intend to use the hardware units wirelessly, get a tri-band system (like the ZenWiFi CT8). Generally, use a dual-band system only if you can have wired backhaul.

      Reply
  7. Hi all- Can I use the Blue Cave as both my modem and an AIMesh hub? (Specturm says it’s authorized and compatible btw) I would like to eliminate the existing Arris modem from the mix if possible and hardwire the Blue Cave to an Asus Ac3100 as part of a whole home AIMesh network. Thanks for the help!

    Reply
  8. Actually I want to point out that is the purpose of the “cave”, it was designed so that the heat is transferred to the plastic inner portion of the cave via the heatsink, which contacts air. I think they were going for something similar to the Dyson fan. The Dyson fan uses some created airflow to pull the air through their hole( think filling a vacuum caused by the air displacement, or the vacuum used when siphoning gas through a tube). while the bluecave design relies on passive exchange, heat is transferred toward the hole in the bluecave, and airflow in the room( I think this is a design assumption that isnt true if placed in a corner or homes without centralized ac/heating) circulates the air. But since the hole material is not metal( to prevent interference from antennas I assume) I question the efficiency of this, but you can place your hand on the gray inner plastic of the hole and feel that heat transfer is occuring. The ventilation holes in back of device allows for some passive ventilation and making holes bigger/more would have little impact if there is no fan in the system to displace the heat unless removing walls completely for a pure open system.

    Reply
    • There are not even proper vents on the top which are really needed. I added those myself. Then the bottom heatsink is upside down and there is not even enough vents there to draw in cool are? The size of the holes are too small for all the heat that comes off that. I fixed that also. the ac-68u was a pinnacle for terrible ventilation even though the design is still one of the very best. I would of thought they would of learned from that alone. The holes are too small for the amount of heat coming off the heatsinks. Best regards

      Reply
  9. Dong, I feel the blue cave and the ac86u are both pretty good as I have seen in various reviews such as yours, Which would you recommend for a 2 story home with 1 Gig connection that has a lot of wifi activity, echos, consoles, wifi cams, etc. currently my 5ghz wifi has horrible range/not usable upstairs

    Reply
    • Hi Preston,

      If your place is large, get the RT-AC86U as the main router and the Blue Cave as a node. You should link them together using a network cable if possible. If not, chances are you won’t be able to get close to full Internet speed via Wi-Fi. Alternatively, you can use a tri-band router as a node (RT-AC5300). For more information, check out this post: https://dongknows.com/asus-aimesh-overview/ and this one: https://dongknows.com/mesh-wi-fi-system-explained/

      If your place is small, a single unit of either the 86U or Blue Cave mounted on the ceiling of the first floor (or close) will do.

      Hope this helps. 🙂

      -Dong.

      Reply
  10. AC68U is router, Blue Cave is node. Backhaul is wired (and set to Ethernet in settings).

    All good when connected to router but when connecting to node, wired or Wi-Fi, the upload speed drops from 300 to 400mb to just 2 or 3.

    download speed halves but as i have a 1000gb connection I can live with that.

    Any ideas as to why upload speeds are dropping right down?

    Thanks Dong

    Reply
    • That’s super odd. I have the Blue Cave as a node myself and don’t experience that at all. Try these:

      1. Restarting the routers.
      2. Using a different network cable to connect the two.
      3. Using a different network port on each to connect them.
      4. Manually updating their firmware. (Download the latest first.)

      Hope that solves it. I can’t think of anything else.

      Reply
    • AC68 bakes temperature wise. Had to modify to get the temp in a safe zone. Hope this Blue Cave does not have the heat issue that one did. I went from well over 140 degrees to under 115

      Reply
      • That is good to hear. read someone said the bottom was really hot of their unit.
        was really shocked at the terrible 3 dimensional grill that was too dense for the heat build up to vent out in real-time. Have one coming and see what I can learn.
        thanks for the reply Dong

        Reply
      • It bakes inside and the ventilation is totally inadequate like some of their other (68u)? Amazing how high tech they are except in this area. They have a good size heatsink actually 2. But that size displaces its share of heat. The holes are way too small to let get rid of that heat in real time? I fixed mine and it will last a while now. When cpu’s get high heat they throttle back clock-rate /performance to protect themselves….. Best regards

        Reply
        • Thanks for the input, Morse. I personally haven’t run into the heat issue at all. But I do live in a relatively cool area and always put networking gear in the open.

          Reply
  11. I currently have a mesh Google Wifi system, but I’m not entirely happy with it’s performance. I’m looking to get the best performance (mainly wired) over a 3000 sq home. I have gigabit (fiber) and was looking for suggestions.

    RT–AC86U as the main hub and the blue cave as an access point? I definitely want the “smart connect” feature so I can just use 1 SSD name. Are there any performance differences between the 2 as far as wired performance is concerned?

    Thanks

    Reply
    • That will work really well. AiMesh is definitely much better than the Google WiFi and wiring is the way to go. Keep in mind though that you’ll not be able to turn the blue light off on the Blue Cave. Also make sure you update both to the latest firmware.

      Reply
    • I assume you meant the RT-AC86U, if so, definitely the latter. 🙂 But you can get one RT-AC86U as the main router and one or two Blue Caves as nodes. In this case, note the blue light, you might not be able to turn it off.

      Reply
      • Dong Ngo, I’m a big fan of your reviews and opinions, CNET currently rates the performance of the AC68U at 10 and the Blue Cave at 8.5 in it’s Best Wireless Routers for 2018 review. Why do you feel the Blue Cave is the “much better” router.

        Reply
        • Thanks for your continued support, Rick. Yes, at its time the RT-AC68u was totally awesome (and it’s still very good now). I reviewed it then. However as time passes by, the newer Blue Cave is now faster and cooler. As for the Blue Cave review at CNET, it was after my time and I had nothing to do with that. 🙂

          Truth be told, for most homes, the differences between the two are minimum. Chances are both will serve your Wi-Fi needs equally well.

          Reply

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