Incorrect DHCP behaviour for 2.4GHz clients, but correct for 5Ghz clients…?

[sm1ng]

Hey, I have the RT-AX86U Pro and in general am happy with it barring this apparent bug.

Please see the screenshot which shows that DHCP should be doling out addresses 192.168.2.2 and up. 

So when I connect via 5GHz, I get a 192.168.2.X address, but when I connect via 2.4Ghz, I get a 192.168.1.X address!?!

This seems blatantly wrong to me but there are many, many configuration options and I’m hoping that someone can show me the error of my ways. Or something.

Furthermore, my 5Ghz devices cannot access 2.4Ghz devices even though client isolation is off and always has been off (I would attach a 2nd screenshot but for some bizzarre reason I’m only allowed one? What is this, 1995 web technology?). Is this a known bug?

Many thanks, 

Peter

[JohnRichard]

Any chance you have a second router acting as a DHCP Server?

[sm1ng]

I do actually. I have one of those infernal Optimum/Alt… router/modem boxes and I cannot turn off its DHCP. Their internet-based web UI is the unbelievably unreliable and has almost no functionality exposed. I’ve called them multiple times to no avail.

And this probably explains the lack of cross-talk between 2.4&5GHz devices. **bleep**. Any ideas on what I can do? Perhaps change the ASUS to repeater/network extension mode? 

[JohnRichard]

I'm unfamiliar with Optimum.  Can you contact them and see if their Modem/Router can be placed in Bridge Mode?   It might be something they have to do on their end (not accessible within their WebGUI).

That way, only your ASUS will be acting as a DHCP Server.

That's what my ISP did for me.  Turned their Modem/Router into "just" a modem; Needed to plug the ASUS WAN into Port 1 of the ISP Modem; so be sure to find out which Port needs to be used.

[sm1ng]

Hey, so I called them and they assured me that they had turned Bridge mode on. 

They hadn’t. Sigh. Their support is woeful SMH.

Thanks again.