I have a wifi shared connection with other flatmates and I'd like to know how can I protect my Debian pc from being sniffed. Should I use a wifi anti sniffer to detect if any wifi card is in promiscuous mode? in that case it's only to detect, but if no wifi cards are in promiscuous mode means that nobody is sniffing right? In the case that someone is sniffing, would be the only solution the use of a VPN to protect my packets? or is there another way to protect from sniffing?
Should I use a wifi anti sniffer...?
These work by detecting responses from the sniffing card - it's not hard to prevent any packets being sent out.
would be the only solution the use of a VPN to protect my packets?
This doesn't stop the packets from being sniffed - it only prevents them from being read or modified. As such it's no different from other forms of encryption (e.g. SSH, SSL). You also need an end point for the VPN before you can access any services outwith the VPN. If you don't trust the people you live with, do you trust the people who manage the VPN end point? Although many routers have VPN capabities I've only ever seen this for the internet facing side - not the LAN side - so unless you know differently your only practical solution to the problem is to build your own router with VPN, DHCP, NAT.