- Do only servers receive unsolicited requests (port forwarding inbound) - No, both servers and client devices can receive unsolicited requests, depending on the context and the network configuration. - In a typical client-server architecture, servers are designed to listen for incoming requests and respond to them. These requests can be solicited, where a client initiates communication by sending a request to the server, or unsolicited, where a client initiates communication without a prior request from the server. - Port forwarding is a technique that allows incoming traffic on a specific port to be forwarded to a designated internal IP address and port. This is often used to make services hosted on a local network accessible from the internet. When port forwarding is configured on a router or firewall, it allows external devices to send unsolicited requests to the specified port, and these requests are then forwarded to the internal server. - However, client devices can also receive unsolicited requests in certain scenarios. For example, peer-to-peer applications or online gaming services may require incoming connections to be established directly with a client device. In such cases, port forwarding or other similar techniques may be used to allow unsolicited traffic to reach the client. - In summary, while servers are more commonly associated with receiving unsolicited requests, client devices can also receive them, particularly in situations where direct connections to clients are needed. - Can you use a VPN instead? - Totally. I think these would be better for a corporate setting when you have something like Kerberos for authorizing to services with a VPN at the perimeter for remote access - The difference is that Cloudflare Tunnels directly maps to the service and gets around port forwarding. This would not be feasible to use if setting up a virtual private cloud or large network - VPNs also require extra layers of abstraction when sometimes you don't need them - Cloudflare Tunnels is a free reverse proxy hosted on their infrastructure that operates on the application layer of the network stack, while VPN operates on the network layer. - Cloudflare Tunnel can only provide access to the specific web server or application that it is configured for, while VPN can provide access to all resources on a network. - [Cloudflare Tunnel Easy Setup | Crosstalk Solutions](https://www.crosstalksolutions.com/cloudflare-tunnel-easy-setup/) -  -  - Does VPN implementation typically require having specific interfaces/logic/setup on routers/firewall? - Yes, the implementation of a VPN (Virtual Private Network) often involves specific interfaces, logic, and setup on routers and firewalls. The exact requirements can vary depending on the type of VPN and the specific network architecture. Here are some common elements involved in VPN implementation: 1. **VPN Protocols:** Different VPN protocols exist, and the choice of protocol can affect the configuration on routers and firewalls. Common VPN protocols include: - **IPsec (Internet Protocol Security):** Often used for site-to-site VPNs. - **SSL/TLS (Secure Sockets Layer/Transport Layer Security):** Commonly used for remote access VPNs. - **L2TP/IPsec (Layer 2 Tunneling Protocol/Internet Protocol Security):** A combination of L2TP for the tunnel and IPsec for security. 2. **Configuration of VPN Servers:** - For site-to-site VPNs, routers at each site typically need to be configured to establish a secure connection. - For remote access VPNs, a VPN server (which can be integrated into a firewall or a dedicated VPN server) must be configured to accept connections. 3. **Network Address Translation (NAT) Considerations:** - If your network uses NAT, you may need to configure your routers or firewalls to allow VPN traffic through NAT. 4. **Firewall Rules:** - Access control rules on routers and firewalls need to be configured to permit VPN traffic. This includes rules for both incoming and outgoing traffic related to the VPN. 5. **Authentication and Authorization:** - VPNs often involve user authentication and authorization. Routers or dedicated authentication servers may be involved in this process. 6. **Key Management:** - IPsec VPNs, in particular, require the management of encryption keys. Proper key exchange mechanisms need to be configured and maintained. 7. **Tunneling:** - VPNs create secure tunnels through which traffic is encrypted. Tunnel configuration involves specifying the endpoints and the encryption settings. 8. **Logging and Monitoring:** - Implementing VPNs typically requires setting up logging and monitoring to track VPN connection status, detect issues, and ensure security. 9. **Dynamic Routing Protocols:** - In complex network setups, dynamic routing protocols may be used within the VPN. Routers need to be configured to handle dynamic route updates. 10. **Client Configuration (for Remote Access VPNs):** - If the VPN is used for remote access, client devices may need specific VPN client software or configuration settings. - It's important to note that the specific requirements depend on the type of VPN (site-to-site, remote access, etc.) and the hardware/software being used in the network. Always refer to the documentation of your specific VPN solution for detailed instructions. Additionally, security best practices should be followed to ensure the integrity and confidentiality of VPN traffic.