A DNS leak happens when your device sends DNS requests outside the VPN tunnel—revealing your real IP location. For IPTV setups, especially when spoofing location is necessary, DNS leaks can trigger bans or access blocks. Use VPN clients with leak protection built-in, and configure custom resolvers like Cloudflare (1.1.1.1) in /etc/resolv.conf. For Windows users, disable “Smart Multi-Homed Name Resolution” via group policy. On routers, disable DoH/DoT if it bypasses your VPN's DNS.