LIMS Network and IIS Troubleshooting (PowerShell Only)

Find LIMS URL From IIS Server

Get your LIMS URL:


Get-IISSite | Select-Object Name, Id, Bindings

The binding output shows your URL - use this as in all commands below

IIS LIMS Troubleshooting Commands

Step 1: Find Your Real Paths First

Find your IIS sites and app pools:


Get-IISSite
Get-IISAppPool

Find your actual LIMS folder location:


Get-WebApplication | Select-Object Path, PhysicalPath
Get-IISSite | Select-Object Name, Applications

Find your IIS log location:


Get-WebConfigurationProperty -Filter "system.webServer/httpLogging" -Name "directory"
# Or check common locations
Test-Path "C:\inetpub\logs\LogFiles\"
Test-Path "F:\inetpub\logs\LogFiles\"
Test-Path "D:\inetpub\logs\LogFiles\"

Replace these placeholders with your real values:

To get :

Run Get-IISSite | Select-Object Name, Id, Bindings and use the part after the last colon

To get other placeholders:

= Real app pool name from Get-IISAppPool
= Real site name from Get-IISSite
= Real physical path from Get-WebApplication
= Real log directory path from Get-WebConfigurationProperty
= Real site ID number from Get-IISSite
= Real server name from connection string
= Real domain name from bindings

Step 2: Use Your Real Paths

When LIMS Site Won't Load At All

Problem: Users get "Service Unavailable"


# First, find all app pool names
Get-IISAppPool

# Check specific app pool status (replace <APP_POOL_NAME> with real name from above)
Get-IISAppPool -Name "<APP_POOL_NAME>"

# Start stopped app pool (replace <APP_POOL_NAME> with real name from above)
Start-IISAppPool -Name "<APP_POOL_NAME>"

# Restart app pool (replace <APP_POOL_NAME> with real name from above)
Restart-WebAppPool -Name "<APP_POOL_NAME>"

When LIMS Loads But Gives 500 Errors

Problem: Users see "Internal Server Error"


# First, find your site ID and log path
Get-IISSite | Select-Object Name, Id, Bindings
Get-WebConfigurationProperty -Filter "system.webServer/httpLogging" -Name "directory"

# Go to log folder (replace <LOG_PATH> and <SITE_ID> with real values from above)
Set-Location "<LOG_PATH>\W3SVC<SITE_ID>"

# Find recent 500 errors
Get-Content *.log | Where-Object { $_ -match "500" }

# Get last 50 error lines
Get-Content *.log | Select-String "500" | Select-Object -Last 50

When Users Get Database Errors

Problem: "Cannot connect to database"


# First, find your LIMS folder
Get-WebApplication | Select-Object Path, PhysicalPath

# Check connection string (replace <LIMS_PATH> with real path from above)
Select-String -Path "<LIMS_PATH>\web.config" -Pattern "connectionstring" -CaseSensitive:$false

# This shows output like:
# <add name="DefaultConnection" connectionString="Server=DB-SERVER01;Database=LIMS_DB;..." />
# <add name="DefaultConnection" connectionString="Data Source=ORACLE-SERVER:1521/LIMS_DB;..." />
# <add name="DefaultConnection" connectionString="Host=MYSQL-SERVER;Port=3306;Database=LIMS_DB;..." />

# Extract server name from the connection string:
# SQL Server: Look for "Server=" or "Data Source=" 
# MySQL: Look for "Server=" or "Host="
# PostgreSQL: Look for "Host="
# Oracle: Look for "Data Source=" (before the colon)

# Example server names from above: DB-SERVER01, ORACLE-SERVER, MYSQL-SERVER
# Use the real server name as <DATABASE_SERVER> below:

# Test database connection (replace <DATABASE_SERVER> and <PORT> with real values)
Test-NetConnection -ComputerName "<DATABASE_SERVER>" -Port <PORT>

# Common database ports:
# SQL Server = 1433
# MySQL = 3306  
# PostgreSQL = 5432
# Oracle = 1521

# For SQL Server specifically:
Invoke-Sqlcmd -ServerInstance "<DATABASE_SERVER>" -Query "SELECT 1"

When File Uploads Don't Work

Problem: Users can't upload files


# Check disk space on all drives
Get-WmiObject -Class Win32_LogicalDisk | Select-Object DeviceID, Size, FreeSpace

# First, find your LIMS folder
Get-WebApplication | Select-Object Path, PhysicalPath

# Check permissions (replace <LIMS_PATH> with real path from above)
Get-Acl "<LIMS_PATH>" | Select-Object -ExpandProperty Access | Where-Object { $_.IdentityReference -like "*IIS_IUSRS*" }

# Check if upload directory exists (replace <LIMS_PATH> with real path from above)
Test-Path "<LIMS_PATH>\uploads"
Get-Acl "<LIMS_PATH>\uploads"

Performance Monitoring

Problem: LIMS is slow


# Check IIS worker processes
Get-Process w3wp | Select-Object Id, ProcessName, CPU, WorkingSet

# Check performance counters
Get-Counter "\Processor(_Total)\% Processor Time" -MaxSamples 5

# Check memory usage
Get-Process w3wp | Select-Object ProcessName, WorkingSet, PagedMemorySize

Emergency Restart


# First, find your site and app pool names
Get-IISSite | Select-Object Name
Get-IISAppPool | Select-Object Name

# Restart specific website only (replace <SITE_NAME> with real name from above)
Stop-IISSite -Name "<SITE_NAME>"
Start-IISSite -Name "<SITE_NAME>"

# Restart specific app pool (replace <APP_POOL_NAME> with real name from above)
Restart-WebAppPool -Name "<APP_POOL_NAME>"

# Full IIS restart
Restart-Service W3SVC -Force

# Reset IIS completely
& "$env:windir\system32\inetsrv\iisreset.exe"

Check IIS Configuration


# First, find your site and app pool names
Get-IISSite | Select-Object Name
Get-IISAppPool | Select-Object Name

# Get site bindings (replace <SITE_NAME> with real name from above)
Get-IISSiteBinding -Name "<SITE_NAME>"

# Get app pool settings (replace <APP_POOL_NAME> with real name from above)
Get-IISAppPool -Name "<APP_POOL_NAME>" | Select-Object *

# Check authentication settings (replace <SITE_NAME> with real name from above)
Get-WebConfiguration -Filter "system.webServer/security/authentication/*" -PSPath "IIS:\Sites\<SITE_NAME>"

# Check application settings (replace <SITE_NAME> with real name from above)
Get-WebApplication -Site "<SITE_NAME>"

Advanced Troubleshooting


# First, find your site name and LIMS path
Get-IISSite | Select-Object Name
Get-WebApplication | Select-Object Path, PhysicalPath

# Check failed request tracing (replace <SITE_NAME> with real name from above)
Get-WebConfiguration -Filter "system.webServer/tracing/traceFailedRequests" -PSPath "IIS:\Sites\<SITE_NAME>"

# Check SSL certificate (replace <YOUR_DOMAIN> with real domain name)
Get-ChildItem Cert:\LocalMachine\My | Where-Object { $_.Subject -like "*<YOUR_DOMAIN>*" }

# Check IIS modules
Get-WebManagedModule

# Check connection strings in all configs (replace <LIMS_PATH> with real path from above)
Get-ChildItem -Path "<LIMS_PATH>" -Recurse -Include "*.config" | Select-String "connectionstring" -CaseSensitive:$false

Network Troubleshooting Commands

Basic Connectivity


# Test if LIMS server is reachable
Test-NetConnection <LIMS_URL>
Test-NetConnection <LIMS_URL> -Port 80
Test-NetConnection <LIMS_URL> -Port 443

# DNS lookup
Resolve-DnsName <LIMS_URL>
Resolve-DnsName <LIMS_URL> -Server 8.8.8.8

# Trace route to server
Test-NetConnection <LIMS_URL> -TraceRoute

HTTP/HTTPS Testing


# Test web server response
Invoke-WebRequest -Uri https://<LIMS_URL> -Method Head
Invoke-WebRequest -Uri http://<LIMS_URL> -Method Head

# Test with detailed output
Invoke-WebRequest -Uri https://<LIMS_URL> -Verbose

# Test specific endpoint
Invoke-WebRequest -Uri https://<LIMS_URL>/api/health -Method Head
Invoke-WebRequest -Uri https://<LIMS_URL>/login -Method Head

# Download response body
Invoke-WebRequest -Uri https://<LIMS_URL>/api/status

# Test with custom headers
$headers = @{"Authorization" = "Bearer token123"}
Invoke-WebRequest -Uri https://<LIMS_URL>/api/data -Headers $headers

Network Information


# Show network configuration
Get-NetIPConfiguration
Get-NetAdapter

# Show DNS cache
Get-DnsClientCache

# Clear DNS cache
Clear-DnsClientCache

# Show network connections
Get-NetTCPConnection | Where-Object {$_.LocalPort -eq 80 -or $_.LocalPort -eq 443}
Get-NetTCPConnection | Where-Object {$_.State -eq "Established"}

# Show routing table
Get-NetRoute

# Show processes using network
Get-NetTCPConnection | Select-Object LocalAddress, LocalPort, RemoteAddress, RemotePort, State, @{Name="Process";Expression={(Get-Process -Id $_.OwningProcess).ProcessName}}

Certificate Testing


# Check SSL certificate
$cert = Invoke-WebRequest https://<LIMS_URL>
$cert.BaseResponse.ServerCertificate

# Get certificate details
$request = [System.Net.WebRequest]::Create("https://<LIMS_URL>")
$response = $request.GetResponse()
$cert = $request.ServicePoint.Certificate
$cert | Select-Object Subject, Issuer, GetExpirationDateString

Common Troubleshooting Scenarios

User can't reach LIMS


Test-NetConnection <LIMS_URL>
Resolve-DnsName <LIMS_URL>
Test-NetConnection <LIMS_URL> -Port 443

LIMS loads slowly


Measure-Command { Invoke-WebRequest -Uri https://<LIMS_URL> }
Test-NetConnection <LIMS_URL> -TraceRoute

SSL/Certificate errors


$request = [System.Net.WebRequest]::Create("https://<LIMS_URL>")
try { $response = $request.GetResponse() } catch { $_.Exception.Message }

API endpoints not responding


Invoke-WebRequest -Uri https://<LIMS_URL>/api/health -Method Head
Invoke-WebRequest -Uri https://<LIMS_URL>/api/status -Verbose

DNS resolution issues


Resolve-DnsName <LIMS_URL>
Resolve-DnsName <LIMS_URL> -Server 8.8.8.8
Clear-DnsClientCache