When writing network-related code, always use named constants from system packages instead of magic numbers, and ensure complete protocol implementation. This includes using proper constants for network operations (like `windows.IfOperStatusUp` instead of `0x01`), calculating buffer sizes correctly with system functions (like `syscall.CmsgSpace(4)` for file descriptor passing), and setting absolute deadlines with `time.Now().Add()` rather than relative durations. Additionally, avoid making assumptions about network infrastructure - for example, don't assume `req.TLS != nil` indicates HTTPS when TLS termination might occur at a load balancer. Always implement complete test scenarios that actually exercise the network paths being tested. Example of proper constant usage: ```go // Bad: magic number if aa.OperStatus != 0x01 { continue } // Good: named constant if aa.OperStatus != windows.IfOperStatusUp { continue } // Bad: hardcoded buffer size oob := make([]byte, 32) // Good: calculated buffer size oob := make([]byte, syscall.CmsgSpace(4)) ``` This approach makes network code more maintainable, portable, and less prone to subtle bugs related to protocol assumptions or system-specific values.