RT-AC68U / RT-AC68P / RT-AC1900 / RT-AC1900P

[fl0w3n]

I got my hands on an RT-AC68U V4 and wound up here in my attempt to find out more about it... I'm just trying to figure out if I should use the V4 as my base for AiMesh or my AC-1900P.

 

[Tech9]

Both have the same radios, but V4 has faster dual-core ARMv8 1.8GHz CPU. I would use V4 as main router.

 

[RMerlin]

I got my hands on an RT-AC68U V4 and wound up here in my attempt to find out more about it... I'm just trying to figure out if I should use the V4 as my base for AiMesh or my AC-1900P.

Was the retailer identifying it as a V4, or did you discover it when you looked at the box's sticker?

 

[fl0w3n]

Actually, I luckily just picked it up used on Craigslist for $30 … score.

 

[mcbobhall]

Both have the same radios, but V4 has faster dual-core ARMv8 1.8GHz CPU. I would use V4 as main router.

V4 has been a big improvement for me, esp. the increase in vram. However, I was unable to use settings from V3 or earlier to restore my V4. Had to take lots of screenshots from my old Web UI pages. I have many custom settings. So, lots of manual re-entry. YMMV

 

[Tech9]

However, I was unable to use settings from V3 or earlier to restore my V4.

This is not a good idea anyway. Completely different hardware and software. Reset to default and configure manually.

 

[mcbobhall]

This is not a good idea anyway. Completely different hardware and software. Reset to default and configure manually.

Yup. I figured that out. Just supports other comments about Asus marketing and product naming.

 

[wouterv]

About the RT-AC68U_V4 being set to EOL.
The RT-AC68U "Classic", RT-AC1900U, RT-AC66U_B1 are NOT yet declared EOL.

 

[maraxion]

Is there any notisable differnce in speed or coverage (5ghz) on the rev A1 vs E1?
Iv got one of each and one is going to be set as primary and the other as media bridge.

Also can these 2 use the same merlin with the different specs?

 

[wouterv]

The version E1 shall perform slightly better than the A1 better due to a little faster CPU.
Both can be loaded with exact the same firmware versions (as long as you don't try an ancient version).

My strong suggestion is to set the Media Bridge to fixed IP settings, like:

Where 192.168.1.1 is the IP Address of the main router.

In the main router set the IP Pool Starting Address to e.g. 192.168.1.3

 

[maraxion]

So i loaded the A1 up now the same way the E1 was before, as a media bridge.
It works great except one thing. If I reboot the main router, the asus A1 do not automaticly reconnect the media bridge on 5ghz, and I have to manually reboot the A1. The E1 did this easily and automatic. Any ideas?

 

[wouterv]

Did you follow my suggestion to setup the Media Bridge with fixed IP settings?
The screen shorts are from my actual setup with a RT-AC68U as main router and the RT-AC1900U as Media Bridge, with the link on 5 GHz.
After reboot of the router, my media bridge does reconnect it self.

The link rate fluctuates a bit between say 850 Mbps and about 1100 Mbps.

 

[maraxion]

Did you follow my suggestion to setup the Media Bridge with fixed IP settings?
The screen shorts are from my actual setup with a RT-AC68U as main router and the RT-AC1900U as Media Bridge, with the link on 5 GHz.
After reboot of the router, my media bridge does reconnect it self.


The link rate fluctuates a bit between say 850 Mbps and about 1100 Mbps.

Hello.
Yes and no, il explain a bit better I figured. First my main router is not an ASUS. I did hoever in this router put the A1 as a static IP, as I always do and things normally work. Still when rebooting as I said it would not auto connect.
This morning hoever it worsened. I got up and the bridge was down, tried to reboot, no go. Got into the ASUS, but the IP did not match the static setup. It also said "connected" as your picture above, but none of the media bridge users had ip or net from that 5G bridge. Tried resetting dident work, then tried your static IP and dident work.
Made a 2.4Bridge instead, and got internet to work with.
Now all this reminded me of similare problems with my E1, so i checked the firmware on that one. Sure enogh on that stable unit i was running stock "3.0.0.4.385_20633" which was pre these massive 90+mb firmwares. I did this because I also had instability with that and tried several firmwares i remember.
So now on the A1 iv downgraded to that version to see if its ok.

In terms of speed/connection I get this(as stated on the router setting, not speed tested):
A1 unit with Merlin 386.9 and 5Ghz:
RSSI: 52-55
Link rate: 525-702

A1 unit with older stock 3.0.0.4.385_20633 and 5Ghz:
RSSI: 59-62
Link Rate: Stable at 1170.

So link rate is quite a bit higher on the old firmware, strangely.

Not sure why im having trouble with these newer firmwares and Merlin to be honest. Any ideas?

 

[wouterv]

It doesn't matter what brand and type main router you have, set up the Media Bridge with fixed IP settings as I outlined and your issues will be gone.
Don't let the main router DHCP give the Media Bridge an IP address.

 

[maraxion]

It doesn't matter what brand and type main router you have, set up the Media Bridge with fixed IP settings as I outlined and your issues will be gone.
Don't let the main router DHCP give the Media Bridge an IP address.

Ok.
So iv been using some hours on this, testing and trying.
Il explain what I do, hoping you see some error in my tries.
After I have flashed any firmware i use the WPS button until power blinks to reset vram.


Old firmware 3.0.0.4.385_20633
With this firmware I just start the install wizard, choose 5g net and with automatic ip it connects and seem stable.

Newest Asus firmware(yours) 3.0.0.4.386.49703 and Merlin 386.9:
With these I now get nothing. The other day atleast I could connect instability, but now its impossible.
So after I flash one of these I go to 192.168.1.1 into the wizard. I choose media bridge and my 5g net. Iv here both tried to put on auto IP, and your tips of placing an IP outside the DHCP. I even tried adding google dns one time to see if it helped, but no go.
If i hoever do the same with the 2.4 net on these firmwares, it connects easily. But it wil not on those firmwares connect on the 5 nomather what I do!

Whenever I want to flash away from one of those firmwares I then have to put in into media bridge 2,4 to get access to firmware settings and change. This because after I put it into 5g I cannot locate its IP.

 

[wouterv]

An issue with 5 GHz was long ago fixed in 3.0.0.4.384.81049
All I can think of is a mismatch of supported 5 GHz channels between the Router and Media Bridge: check which channels the Router does support and temporay set the Media Bridge device in Router mode to see what 5 GHz channels are supported,.
I can slightly remember I has issues with finding 5 GHz in the wizzard longer ago, then I used the manual entry option for the SSID.
To avoid you need to search for the Media Bridge IP address, please again: make manual IP settings in the Media Bridge.

[EDIT]
In case of trouble, what does the Syslog of the Media Bridge tells you?

 

[maraxion]

An issue with 5 GHz was long ago fixed in 3.0.0.4.384.81049
All I can think of is a mismatch of supported 5 GHz channels between the Router and Media Bridge: check which channels the Router does support and temporay set the Media Bridge device in Router mode to see what 5 GHz channels are supported,.
I can slightly remember I has issues with finding 5 GHz in the wizzard longer ago, then I used the manual entry option for the SSID.
To avoid you need to search for the Media Bridge IP address, please again: make manual IP settings in the Media Bridge.

[EDIT]
In case of trouble, what does the Syslog of the Media Bridge tells you?

Thanks il have a try, just need to pick a day the family dont need the wifi

Anyways my primary router has been an old Zyxel P8702N for years, just gotten used cheap ones and swapped. Its an old dual core 400mhz device 128Mb Ram/and flash. Old style Broadcom BCM63168. Its a bit unstable doh and reboots too often, thats why I wanna change.

The above unit with asus ac68U in media bridge(old firmware offcource) has been stable on 350/300 with my maxed line speed at paid 350. So i figured another AC68 v.E1 instead of teh zyxel as a main router with dual core 1000mhz would atleast keep the same speed.
So i tried now with E1 unit as a temp primary, and was a bit taken aback when the speeds was way less. When testing the speed starts at around 200 but then drops down to like 50 during the test. Any ideas to this?
5g, set to clean channel, width 80. Not sure why this clearly superior router is so mych worse. Its link rate is also good at 1170 to 866 and lower RSSI.
Puzzled.

 

[wouterv]

Back to the basics:
Guideline in case of unexplained router behavior:

1. If there are, disconnect all USB devices.
2. Install the latest available firmware version.
3. Reset to factory defaults.
4. Do not load an old configuration backup file.
5. Manual configure the router with the bare minimum, as:
   • Router Login Name.
   • Router Login Password.
   • WAN Connection Type, and what is required to connect to the Internet.
   • Wireless SSID's and WPA Pre-Shared Key's.
   • Leave everything else default.
6. Test the router behavior:
   1. Test with a wired connection first.
   2. Test with a wireless connection.
7. After the above works all well you can consider more manual router configuration changes.

Notes to the above guideline:

• Restoring a configuration backup might bring back old issues, that is why the manual configuration is advised.
• While making configuration changes: write them down so you do have a list of changes you made from factory defaults.
• Whenever you restore a configuration backup: only restore the backup to exactly the same firmware branch and version as it was made with.

Then specially for the RT-AC68U I experienced those setting are best:

• Advanced Settings - Wireless - Professional - 2.4 GHz:
  • Modulation Scheme: Up to MCS 7 (802.11n)
  • Airtime Fairness: Disable
  • Explicit Beamforming: Disable
  • Universal Beamforming: Disable
• Advanced Settings - Wireless - Professional - 5 GHz:
  • Airtime Fairness: Disable
  • Universal Beamforming: Disable

 

[maraxion]

Back to the basics:
Guideline in case of unexplained router behavior:

1. If there are, disconnect all USB devices.
2. Install the latest available firmware version.
3. Reset to factory defaults.
4. Do not load an old configuration backup file.
5. Manual configure the router with the bare minimum, as:
   • Router Login Name.
   • Router Login Password.
   • WAN Connection Type, and what is required to connect to the Internet.
   • Wireless SSID's and WPA Pre-Shared Key's.
   • Leave everything else default.
6. Test the router behavior:
   1. Test with a wired connection first.
   2. Test with a wireless connection.
7. After the above works all well you can consider more manual router configuration changes.

Notes to the above guideline:

• Restoring a configuration backup might bring back old issues, that is why the manual configuration is advised.
• While making configuration changes: write them down so you do have a list of changes you made from factory defaults.
• Whenever you restore a configuration backup: only restore the backup to exactly the same firmware branch and version as it was made with.

Then specially for the RT-AC68U I experienced those setting are best:

• Advanced Settings - Wireless - Professional - 2.4 GHz:
  • Modulation Scheme: Up to MCS 7 (802.11n)
  • Airtime Fairness: Disable
  • Explicit Beamforming: Disable
  • Universal Beamforming: Disable
• Advanced Settings - Wireless - Professional - 5 GHz:
  • Airtime Fairness: Disable
  • Universal Beamforming: Disable

Fantastic guide wouterv.
It actually got fixed after I went into settings and restored it to factory settings and initialized all like you wrote. Not sure what it removed but now my Up/down is maxed to my line of around 370/360
Thank you!

Btw I see your running stock, is there any reason why you dont use Merlin?

 

[wouterv]

I see your running stock, is there any reason why you dont use Merlin?

Because I have no reason to use Asuswrt-Merlin.