Mountain Lion can't see 2.4GHz wifi SSID, but 5GHz

[niotio910]

Hi,

I just bought a new router dual-band Asus rt-n56u. I set it up with 2 SSIDs 2.4GHz and 5GHz. All bands are configured with WPA2 encryption

I installed the latest mountain lion on my MBP late 2011, and I didn't have any issue with the old router. However, the wifi issue has started to happen since I bought the asus router. The problem is that when I start up my macbook, I cannot see 2.4GHz access point on the list of AP, but I can see the 5GHz. However, whenever it gets connected to the 5GHz AP, then I can see the 2.4GHz AP appearing on the list.

I don't have any problem with my windows laptop, iphone and ipad. Another problem is that, I don't use the 5GHz connection with ML because it's very sluggish.

I know that there're a lot of Wifi issues with ML. I tried different solutions suggested but I can't solve the problem. One thing I haven't tried is to clean install the ML.

Any suggestion will be appreciated!
Thanks!

 

[satcomer]

When you setup the 5GHz did you use the 100+ channel range? If not for the 5GHz change the channel to 100+ channel range. See if that helps.

 

[niotio910]

When you setup the 5GHz did you use the 100+ channel range? If not for the 5GHz change the channel to 100+ channel range. See if that helps.

I set different channels available in my router (US, Europe, Taiwan ...) but it didn't help

I just did clean installation and upgraded to 10.8.3, but it didn't help either.

 

[00maximus]

I have the same issue, I never noticed it since my iMac is always connected to 5Ghz WiFi and it works fine, but it cannot connect to 2.4Ghz. I've tried everything I found on the web but no luck..

Actually I can see both the 2.4Ghz and the 5Ghz WiFi networks, and can connect to both, but when I connect to the 2.4Ghz even though it says that it is connected, with an IP address and all the rest I cannot ping the router. If I simply switch to the 5Ghz WiFi then it works perfect..