RT-AC68U dual WAN, split WANs to 2.4 / 5 GHz

[Marvin A]

I have the RT-AC68U set up with dual WAN (ADSL + 4G dongle) in failover mode. Works just fine.

I also have set up two wireless networks, one for 2.4 GHz and one for 5 GHz.

Is there any way to configure the router so both WANs are always in use, one for 2.4 GHz and the other for 5 GHz?

I'm primarly asking this because it takes up to 2-3 minutes for the backup 4G connection to kick in when the primary ADSL fails. I always use 5 GHz by default, but if I could split up the WANs, instead of waiting for the backup 4G to kick in, I could have it running 24/7 on the 2.4 GHz band and simply switch to 2.4 GHz as soon as the primary WAN fails.

 

[Marvin A]

Couldn't figure out a way to do it, so I bought a cheap second router to use with 3G/4G only on the 2.4GHz band, while the RT-AC68U uses 5GHz only.

 

[L&LD]

Probably the easiest, cheapest and the least buggy way to do it.

 

[SoCalReviews]

Keep your current setup but also run an Ethernet cable from the cheap second router LAN port to the selected fail-over port on the ac68u and now you will not only have separate wireless for the 2.4Ghz wireless from the 3G/4G WAN Internet source... but you will have 5Ghz for your primary internet ADSL WAN source and you will also continue to have the 3G/4G secondary internet source for fail-over on the ac86u running 5Ghz (via the cheap secondary router) . The best of all worlds setup.