2012 MBA - 2.4GHz Connection Issue

[Jelsoft]

Okay, I am totally stumped and don't know where to turn.

I have 2 Cisco routers where I live. I don't know what the main modem they connect to is.

One of them (R1) supports 2.4GHz/5GHz, and the other (R2) supports (or at least only provides) 2.4GHz.

I don't know how they all connect to each other. I know R1 take an ethernet cable, whilst R2 takes just a power cable.

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When in good range, I can connect my new MBA using the R1 no problem (@5GHz), but it detects the 2.4GHz channel too.

However, when in good range, it cannot even discover R2.

Yet, like I say, when in good range it can discover and connect to R1, and it can detect BOTH the 2.4 and 5ghz channels being given off of this router.

What is even more weird is that my 2010 MBP has the same situation with R1, but when in good range of R2 it connects (@2.4GHz)

One final thing to add is that from where R2 is, both my MBA and MBP can *just* about pick up the 5GHz band of R1, but it's too far for them to connect.

The MBP can also detect R1's 2.4GHz signal, whereas the MBA cannot.

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NB: the 2.4GHz band channel of R1 and R2 are both the same, if that were an issue, but it doesn't seem to bother the MBP at all.

To summarise:

R1: 2.4/5
R2: 2.4

MBP in good range of R1 - Detects both 2.4 and 5 of R1; connects to 5 of R1
MBP in good range of R2 - Faintly detects both 2.4 and 5 of R1; detects 2.4 of R2; connects to 2.4 of R2.

MBA in good range of R1 - Detects both 2.4 and 5 of R1, connects to 5 of R1
MBA in good range of R2 - Faintly detects 5 of R1; detects nothing of R2; cannot connect to anything.

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What do I do? I just got this MBA and trust me, returning it is not an option for far too many reasons to list.

Am I doing something stupid?

Please help. I can't work by R1 as it isn't in my room. R2 is in my room. The MBP isn't mine to use.

 

[southerndoc]

Do you have MAC filtering enabled on your second router?

 

[Jelsoft]

Hi, thanks for your response.

I don't actually know. Is there a way for me to test this using one of the macbooks?

And, is there any possibility this is a hardware fault on the MBA's side, or is more likely a fault on R2's side? I only ask because I've never had any problem with the MBP and R2...

 

[Jelsoft]

Okay, MAC Filtering is not enabled on any of the routers.

Anyone else have any other idea? Could I be right that it's the fact that R1 and R2's 2.4GHz are on the same channel, but because R1's 5GHz channel is detectable (though not connectable) R1's 2.4GHz band effectively cannibalises R2's 2.4GHz band?

I can't change the channels without a lot of bother (complicated to explain) so I'd rather someone with some know-how explain to me that this could actually be the issue, or rather that it's more likely something wrong with my MBA (cos the MBP works just fine in my room, despite detecting R1)