Network Diagnostics Skill
When to Activate
- •User mentions: connectivity, DNS, ping, traceroute, port, firewall, routing, network unreachable
- •User asks why a server can't reach another server
- •User reports "connection refused" or "timeout" errors
Diagnostic Workflow
Step 1: Identify the Target
powershell
# Extract hostname/IP and port from user's description $target = "hostname-or-ip" $port = 443 # or whatever port is relevant
Step 2: Basic Connectivity
powershell
# Quick ping test Test-Connection -ComputerName $target -Count 4 # DNS resolution Resolve-DnsName $target -Type A Resolve-DnsName $target -Type AAAA
Step 3: Port Accessibility
powershell
# TCP port test
Test-NetConnection -ComputerName $target -Port $port -InformationLevel Detailed
# Multiple ports at once
@(22, 80, 443, 3389, 5985) | ForEach-Object {
Test-NetConnection -ComputerName $target -Port $_ -WarningAction SilentlyContinue |
Select-Object ComputerName, RemotePort, TcpTestSucceeded
}
Step 4: Route Analysis
powershell
# Trace the path Test-NetConnection -ComputerName $target -TraceRoute # Or classic tracert for more detail tracert -d $target
Step 5: Local Firewall Check
powershell
# Check if Windows Firewall might block
Get-NetFirewallRule | Where-Object {
$_.Enabled -eq 'True' -and $_.Direction -eq 'Outbound'
} | Select-Object DisplayName, Action -First 20
Common Issues & Solutions
| Symptom | Likely Cause | Check |
|---|---|---|
| DNS timeout | DNS server unreachable | nslookup $target 8.8.8.8 |
| Connection refused | Service not running | Test-NetConnection -Port |
| Request timeout | Firewall blocking | Check both local and remote FW |
| TTL exceeded | Routing loop | tracert to find the loop |
| No route to host | Missing route | Get-NetRoute -DestinationPrefix 0.0.0.0/0 |
Output Format
Always report:
- •What was tested
- •What succeeded ✅
- •What failed ❌
- •Recommended next step