You are using a public Wi-Fi network inside a coffee shop.

You should check your ARP table and see if there is one IP address with two different MAC addresses.

You should scan the network using Nmap to check the MAC addresses of all the hosts and look for duplicates.

You should use netstat to check for any suspicious connections with another IP address within the LAN.

You cannot identify such an attack and must use a VPN to protect your traffic, r