Report on Current Issues and Configuration Attempts

Overview

This document summarizes the ongoing challenges, configurations, and insights based on our attempts to establish and debug the setup for the Model Context Protocol (MCP) servers (“SQLite”, “Filesystem”, “GitHub”) in a virtualized Ubuntu 24.04 environment, hosted on a Windows 11 machine using VirtualBox.

Current Environment

Host (Windows 11)

• Role: Primary physical system managing virtual machines.
• Tools:
  • VSCode
  • Claude Desktop
  • MCP Inspector
• Network Configuration:
  • Port forwarding enabled:
    • SSH: Host: 2222 → Guest: 22
    • SQLite: Host: 7777 → Guest: 7777
    • Filesystem: Host: 7778 → Guest: 7778
    • GitHub: Host: 7779 → Guest: 7779

Guest (Ubuntu 24.04 VM)

• Role: Server providing MCP functionality.
• Key Services:
  • OpenSSH (working and confirmed via port 2222).
  • MCP servers (SQLite, Filesystem, GitHub).
• Network Configuration:
  • Adapter: NAT
  • IP: 10.0.2.15/24
  • Port forwarding matches the configuration above.

Key Problems Identified

Problem 1: MCP Ports Not Active

• Observed Behavior:
  • The MCP server processes (e.g., uvx mcp-server-sqlite) execute without errors but fail to show up as listening on the assigned ports (7777, 7778, 7779) when checking with sudo netstat -tuln or sudo ss -tuln.
• Evidence:
  • Running sudo netstat -tuln and sudo ss -tuln does not list the expected ports as active.
  • Verified that SSH (port 22/2222) works correctly, indicating the NAT and port forwarding are functional for other services.
• Possible Causes:
  1. The MCP servers are not starting properly.
  2. Incorrect binding configurations in the MCP server commands or environment.
  3. Misalignment between NAT port forwarding and guest OS network services.

Problem 2: Uncertainty Between Host and Guest Roles

• Clarification:
  • Host (Windows 11):
    • Manages the VM via VirtualBox.
    • Redirects forwarded ports (e.g., 127.0.0.1:7777) to the VM.
  • Guest (Ubuntu 24.04):
    • Provides the actual services (MCP servers) bound to 127.0.0.1 and exposed via forwarded ports.
• Implication:
  • Misunderstanding the host-guest roles could lead to misconfigured bindings, such as binding MCP services to the wrong IP (0.0.0.0 or 127.0.0.1).