What is Split DNS and how to solve the problem of using corporate VPN and external VPN simultaneously to access blocked resources?

Split DNS is a method of configuring DNS where the same domain resolves to different IP addresses depending on the source of the request (for example, from a corporate network or from the internet). This allows separating internal and external addresses for the same domain names.

The problem with simultaneously using corporate VPN and external VPN to access blocked resources arises from routing conflicts and DNS queries: the corporate VPN may redirect all traffic and DNS requests through itself, blocking access to external resources.

Solutions:

1. Configure Split Tunneling — allows directing traffic to corporate resources through the corporate VPN, while other traffic goes directly or through an external VPN.

2. Use Split DNS — configure DNS so that requests to corporate domains go through the corporate DNS, and others go through public DNS servers.

3. Configure route priorities — properly set up routing tables so that traffic to blocked resources goes through the external VPN, and corporate traffic through the corporate VPN.

4. Use virtual machines or containers — run the external VPN in an isolated environment to avoid conflicts with the corporate VPN.

Thus, by combining Split DNS and Split Tunneling, it is possible to ensure simultaneous access to corporate and blocked external resources without conflicts.