The TCP/IP protocol is the foundation of the internet and pretty much every single network out there. The protocol was designed 45 years ago and was originally only created for connectivity. There’s nothing in the protocol for security, mobility, or trusted authentication.
The fundamental problem with TCP/IP is that the IP address within the protocol represents both the device location and the device identity on a network. This dual functionality of the address lacks the basic mechanisms for security and mobility of devices on a network.
This is one of the reasons networks are so complicated today. To connect to things on a network or over the internet, you need VPNs, firewalls, routers, cell modems, etc. and you have all the configurations that come with ACLs, VLANs, certificates, and so on. The nightmare grows exponentially when you factor in internet of things (IoT) device connectivity and security. It’s all unsustainable at scale.