How to know it is someone using some software for example p2pover to control the network?
Because i am not sure it is some users is using this software to control my hotspot network. it is a hotspot network and may up to 400+ clients, it is hard for me to check.
Search the forum for arp poisoning. This is the same thing.
The very best thing that you can do and should do is to isolate users from each other on the network. This is done via managed switches (either port isolation or VLANs) and access points that do client isolation. This means that guests cannot talk directly to each other over the layer2 network. This is not something can can be done on the layer3 hop of a network (your router), as guests do not need to use the router to talk to someone that shares the same layer2 network as them.