Why can't I bind to a specific IP address? This webserv instance runs inside a sandboxed container without dedicated network interfaces or assigned IPs — it only has access to the loopback/bridge address, so binding to a custom IP isn't possible here. Listening must be done on 0.0.0.0 (all interfaces) or 127.0.0.1.

Allowed ports: for the same sandboxing reason, only a fixed set of ports are exposed to the host. You may configure listen on: 8080, 4242, 8888, and 9090. Any other port will fail to bind.