Add error handling for grep when no Docker DNS rules exist, preventing
script failure on default Docker networks while still preserving DNS
functionality on custom networks.
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
- Extract Docker DNS NAT ports before iptables cleanup
- Restore Docker DNS NAT rules after iptables reset
- Maintains Docker container DNS functionality in network isolation
- Fixes connection refused errors to 127.0.0.11 in Docker environments
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>