netcheck

A powerful bash-based network connectivity testing tool that supports:

Core Testing Features:

• ICMP ping testing with statistics and URL support
• DNS lookup with multiple fallback methods (accepts URLs)
• TCP port connectivity testing with parallel processing
• HTTP/HTTPS status code checking with performance metrics
• SSL/TLS certificate validation with expiry warnings

Network Diagnostics (v1.2.0):

• Show network interfaces with IP addresses (--my-ip)
• Retry failed connections with configurable count and delay
• HTTP status codes with response time and content size
• SSL certificate expiry check with advance warnings

Advanced Features:

• Parallel TCP connection testing (up to 256 concurrent jobs)
• Quick mode parallel processing for wide IP ranges
• Output file support for quick mode results (-o flag)
• IP range support (192.168.1.1-50)
• CIDR notation (10.0.0.0/24)
• Port ranges (8000-8100) and multiple ports (80,443,3306)
• CSV file input for bulk testing
• Multiple output formats (text, JSON, CSV, XML)
• Comprehensive input validation with helpful warnings
• Real-time progress tracking
• Combined reports with dated filenames

Perfect for:

• System administrators monitoring infrastructure
• DevOps engineers validating deployments
• Network diagnostics and troubleshooting
• DNS resolution verification
• ICMP connectivity testing
• HTTP/HTTPS status monitoring
• SSL certificate expiry tracking
• Security auditing and port scanning
• Load balancer health checks

IMPORTANT: For full functionality, run after installation: sudo snap connect netcheck:network-observe

This connection enables:

• ICMP ping tests (-p/--ping flag)
• Network interface information (--my-ip flag)

Without this connection, features like TCP port tests, DNS lookup, HTTP status checks, SSL certificate validation, and retry logic work normally.