How does the ad page appear?

Question

Computer networks

I am connected to a point that distributes the Internet both via LAN and Wi-Fi. For me (and for everyone who is also connected to the point), when surfing the Internet, a page with ads sometimes crashes . Yes, I'm sure this is the work of the network administrator. But how does he do it? Is there any way to prevent/bypass this?

Answer 1

Well, if the channel is in the hands of the system administrator, then nothing prevents you from inserting a bit of extra content into the body of the page without any DNS. True, this will not work over HTTPS. Try to surf on HTTPS sites. If there is no advertising, then HTTP traffic is being modified directly.