Not sure if I used the correct terms but what is the difference in security and privacy between downloading from a public wifi (or a closed wifi; with password) and mobile hotspot (sharing 4G/5G data from your phone to your computer)? Which one is recommended or does it not matter?
most properly configured public wifi will enable client separation, of course that potentially still leaves lower level protocol and radio attacks.
I have no idea what this client separation is.
As far as I know there isn’t really any client separation on wifi. It’s a shared medium.
At least I don’t see anything preventing you from reading someone else traffic. So anything unencrypted on a wifi is also accessible to any other clients.
I had tools more than 10 years ago that could automatically hijack session cookies on wifi for anybody connected and not using https.
no worries.
the net effect of client separation is that your device sees no other layer 2 devices on the wlan besides the gateway. this would typically be enforced at the frame level by the APs and is separate from any radio privacy cryptography.
a properly configured wireless setup would assume every client is compromised and would also disallow local client-client via source routing or proxy ARP or any other escape options. 100% secure? probably not, but its a non trivial barrier that would have to be circumvented.
as with e.g. broken WEP years ago, there are still options to mess with clients at ~Layer 1 but I dont believe its currently as trivial as it used to be.
Do you have any documentation on how this work ? Is there a name to this special protocol? Is it a recent addition to the wifi standard ?
Again a wifi AP doesn’t send data to a specific client. So how does an AP can enforce that one client can’t read a frame for someone else that is properly authenticated? How would an AP prevent someone spoofing mac addresses from receiving that data ?
I’m really confused by this feature I never heard of even when I was playing with aircrack and so on. Yes sometimes your mac address can get filtered but even that is not really difficult to avoid.
Sorry I have so many questions but I honestly did quite some “tinkering” with wifi years ago and none of this sounds familiar.
Client seperation is implemented by the AP. There’s lots of info, it’s called client isolation normally. check this out
To add to the other reply, client isolation is about controlling whether an ap, switch, or router willingly sends traffic between clients. Because of that, it doesn’t kick in if you listen to packets over the air before they’ve been received by an AP. For that kind of security you need a wifi specific security measure - which I think “enhanced open” is what you’d be interested in. It allows you to have an open passwordless wifi but it generates temporary encryption keys for each connected client, then the rest is as if it was using WPA, so that you don’t need to enter a password but your traffic gets encrypted and protected from anyone else listening in on the WiFi.
If you combine both then you should have a network where each device is isolated both over the air and from a routing perspective so that each device only sees an Internet connection and no other devices.
Is this similar to vLAN that could be configured in my router but I never bothered since it was overkill for me?
You can achieve a similar thing using vlans - usually by default they’re isolated but you may add specific rules that allow traffic between vlans if it meets certain criteria (specific ports, specific types of traffic, traffic to or from specific hosts, any combination of those). So yeah you can imagine client isolation being like having each client on their own vlan - except without needing a different subnet for each client.
Thanks ! That’s exactly how I think it could be implemented but that confirms that this is certainly not something you can find commonly where I live.
That confirms the fact that if you use the same wifi and everyone has entered the same encryption key then there is no real client isolation…
It’s cool that wifi keeps evolving. It comes a long way from the WEP beginnings.
Good explanation, a note that most public WiFi will use client separation. Macca’s, starbucks, airplanes etc you will only ever see your device and the gateway. (More for other people that are reading, I assume you know this 😄)
Client separation on WiFi is supposed to force clients to only talk to the AP and prevent them from talking directly to each other. The motivation is to allow the AP to enforce appropriate policies.
The feature may well be as antiquated as WEP now, it’s been years since I looked into how it actually functions.