I love the idea of setting up a guest network to segregate a one-time guest from my own network. I'm curious, though, how the guest network works. Could someone please explain that to me? Will it have an impact on the performance of my own wireless network?

Assuming you wire the visitor AP to the rest of your network and have it on a different wireless channel, you shouldn't see any noticable degradation in your own network.

My setup is a dual-band router with 802.11n at 5 GHz and 802.11g on 2.4 GHz channel 6, with my visitor AP serving up 802.11g on 2.4 GHz channel 1 (too much interference on channel 11.) I've noticed no problems after adding the visitor AP, but then again, almost all of my devices are hard-wired or on the 802.11n network at this point.

Tony, I think we're talking about different things here. I'm talking about the "guest network" setting that many routers have today, including the last model or two of Airport Extremes. My Netgear router has it and I guess I was just looking for an explanation for how it can broadcast two different networks. I'm able to set up a guest network on both the 2.4GHz and 5GHz bands.

Oh, okay -- that's a different animal, then. Never seen anything like that, but I don't see how it could *not* have some negative impact performance.

That's what's making me curious. I don't understand how it's broadcasting two networks at the same time. Today I even saw a router that advertised the ability to create 4 guest networks. I'm not even sure why you'd need that many

Coming from the VFX industry, where everyone is paranoid about their projects leaking out, I can easily see businesses having a desire to isolate clients that are in the building to their own guest network.

Or you could use the different guest networks to provide service tiers, blocking different protocols on a network basis.

Matt, you're going to reduce bandwidth, but likely no more than when simply adding a new client to your primary network - at least while that connection is in use.

There's a ton of information out there about setting up an Apple device and other dual-band devices, including discussions on Apple's own forums and knowledge base. Surprisingly in fact. Unsurprisingly, I haven't been able to locate actual benchmarks yet, but i haven't looked hard either.

I've only looked briefly, but so far I haven't seen anything to indicate that bandwidth is lost when a guest is not currently connected.

That's mainly what I'm wondering. I was hoping that broadcasting a second SSID on the same equipment wouldn't impact performance too much.

It looks like the Tomato hackers are experimenting with multi-SSID guest network functionality, but it's really bleeding edge so far. If it turns into something that can be secured and rate-limited easily, I think I'd rather use that than my multi-radio setup to save some power.

Anyone else who's interested might want to follow this git branch where the guest network commits are happening.

That's one of the reasons I'm turning on my guest network as well. I had planned on adding a second access point, but this is FAR easier (and you don't need Tomato in order to do it).

In my router's admin page you even get a few nice options to go along with it, and I can set up each band individually. If I don't choose any options, it essentially acts as a second network, putting all the people who connect on that SSID in their own bin that can't touch the main network, though people on that network can see each other. I then have the option to isolate users on the guest network so that they can't see each other. I can also go the other way and tell the router to let guest users see my content. I don't know why I'd do that, though, since I'd think the whole idea of having a guest network is to have a network separated from your stuff...

Anyway, I've enabled the guest network on both bands on my router, so I'll see how it goes

The main reason for the guest network function is to allow non corporate users to access the internet without going across your core network. This provides a useful service (so your guests can use their iPads etc) without compromising your own network security.

Legally it is also quite useful to be able to say - we just act as provider of the carrier service on the guest network - as then responsibility for anything that happens on that network is almost zero.

Most routers that I see with this use two separate frequencies and two separate ethernet segments. I wouldn't use one that didn't have both of these - the first to avoid killing bandwidth, and the second to provide a gap between networks.

I understood the reason for the guest network, but not how it works or what effect it has on home wireless when using routers that aren't the variety you're talking about.

How would they use separate frequencies? Aren't you pretty much tied to either 2.4GHz or 5GHz?

2.412 GHz (channel 1) is different then 2.462 GHz (Channel 11). That's all channels are, just a different name for frequency.

Ah, that's right. Sorry, forgot about that.