When I play Diabotical, the game lists available servers, but connection attempts fail unless I enable a VPN. I spoke with one of the server hosts, and they said no packets from my connection reach the server when I try to join. What could be blocking the connection, and how can I fix it without relying on a VPN?
1 Answer
This sounds like a routing or regional-blocking issue. The restriction could be configured by the server host, the game’s network provider, your ISP, or a government-level filter. Since the VPN changes your route and makes the connection work, compare the VPN’s exit region with your normal connection and ask the host whether they block your country or IP range. You can also try rebooting your modem, changing DNS servers, checking firewall and router settings, and contacting your ISP to see whether traffic to the server is being filtered.

How can I tell whether the block is coming from the server host or from my ISP or government?