Wireless client and software AP with a single Wi-Fi device

paul_chany

Hi,

I have a laptop with a WiFi adapter:
Network controller: Qualcomm Atheros AR9462 Wireless Network Adapter (rev 01)

It works as a wireless client already on my Gentoo linux system intsalled on this laptop.

When I had installed on this laptop Arch linux, I can set it up by following this article:
https://wiki.archlinux.org/index.php/Software_access_point

Then I were able to use this WiFi adapter as a wireless client and software AP.

Can it be set up as a wireless client and software AP with this single Wi-Fi device on Gentoo Linux too?
_________________
Best, Pali

Roman_Gruber · Posted: Sun Feb 12, 2017 1:36 pm Post subject:

When it is only software related yes. Same steps should work

paul_chany · Posted: Mon Mar 13, 2017 8:05 pm Post subject:

cboldt · Veteran Joined: 24 Aug 2005 Posts: 1046

Maybe missing nothing. I get the same WARNING type messages here on starting wireless network, and the things that are delayed until the network is up, are just delayed until the network comes up. When the network comes up (which it does "every time"), those other services start.

I can prove my network is up by the "route" or "ifconfig" commands.

I'm not saying your hostap is up, but the fact that startup threw warning that it hadn't started YET, does not mean it didn't start "eventually" - usually a few seconds later.

khayyam · Posted: Mon Mar 13, 2017 9:22 pm Post subject:

paul_chany ...

I can see a number of problems, the bigest of which is you're not configuring wlp3s0_ap as 'null' and are not adding to it the bridge (you're adding enp2s0f0, which just adds to the confusion). You're also setting hostapd INTERFACES to wlp3s0 rather than br0. Anyhow, before trying to address any of that one simple question, if you have enp2s0f0, then why create a phy on wlp3s0? Surely this isn't needed, if this is the case. I think (though I'm not sure) what you want is this:

paul_chany · Posted: Tue Mar 14, 2017 8:43 am Post subject:

khayyam · Posted: Tue Mar 14, 2017 12:14 pm Post subject:

paul_chany · Posted: Tue Mar 14, 2017 1:15 pm Post subject:

paul_chany · Posted: Sun Mar 19, 2017 7:37 pm Post subject:

For what I want to do is maybe best to create a software AP with hostapd on my laptop.
Then my pupils can uses their mobil phones to connect to the wireless LAN of my laptop and there reach my Moodle local site, mining that that this Moodle site is running only on my laptop and can reached only in this wireless LAN. In this case pupils should not reach the Internet at all, but only my Moodle site which is running on my laptop.
_________________
Best, Pali

szatox · Advocate Joined: 27 Aug 2013 Posts: 3137

Yes, you can do that. As long as you don't explicitly bridge that ap to the network (or route traffic), your AP will effectively be isolated sector.
Bear in mind that a single wifi can only work on one channel at any time, so if you want to connect to school's wifi and let the pupils connect to you, they will share school AP's bandwidth anyway.
Second device sending data at the same time would clash with the first jamming both transmissions, regardless of the access point they are talking to. If they see each other, they must wait for each other.

paul_chany · Posted: Sun Mar 19, 2017 9:11 pm Post subject:

szatox · Advocate Joined: 27 Aug 2013 Posts: 3137

Wrong. You can stay connected yourself. However, your MASTER and your STA interfaces refer to the same physical device, which can only use one frequency at any time. Using this feature you end up with 2 networks in close proximity sharing the same medium, so all machines connected to either of those networks will compete for bandwidth.
Depending on your use case this may or may not be an issue. E.g. if you're worried about bandwidth on the connection to the outer world, that distant connection is likely to be the bottleneck anyway, so there is no problem. Your pupils can't access it.
However, if you transfer a lot of data within your private sector, you may just as well jam the main network because you're sharing the same channel. In this case it won't be a problem for you (you are in a single room = excellent signal strength), but you may be a problem for other people trying to use the main AP over slightly larger distance, or separated by a wall.
Something to be aware of. Wifi is a bad neighbour for wifi.

On the other hand, if you decide to disconnect yourself, you will be able to pick another frequency. If you go 6 channels away from other networks, your frequencies will not overlap. Something around 12 channels in case of N networks.
In this case those networks will NOT share the same medium even if they are in the same room, which means each of those networks can have all of it's bandwidth for itself. But you have to find another way to reach out to the internet. Like wire yourself or somethin'