GitHub Hosts Optimizer

On Windows, directly modify C:\Windows\System32\drivers\etc\hosts to map GitHub domains to faster IPs.

Workflow

1. Resolve GitHub IPs using nslookup:

   • github.com
   • api.github.com
   • objects.githubusercontent.com

2. Ping each IP to measure latency (ping -n 3 \x3CIP>)

3. Select fastest IP (lowest average latency)

4. Update hosts file with entries:

   \x3Cfastest_ip> github.com
   \x3Cfastest_ip> api.github.com
   \x3Cfastest_ip> github.com  (duplicate for reliability)
   

5. Flush DNS cache:

   ipconfig /flushdns
   

PowerShell Script

$hostsPath = "$env:SystemRoot\System32\drivers\etc\hosts"
$domains = @("github.com", "api.github.com", "objects.githubusercontent.com")

# Resolve IPs
$ips = @{}
foreach ($domain in $domains) {
    $result = nslookup $domain 2>$null
    $ips[$domain] = ($result | Select-String -Pattern "Addresses:" -Context 0,10 | ForEach-Object { $_.Context.PostContext }) -replace '\s+', '' | Where-Object { $_ -match '^\d+\.\d+\.\d+\.\d+$' }
}

# Ping each IP and find fastest
$results = @()
foreach ($ip in ($ips.Values | Select-Object -Unique)) {
    $avg = (ping -n 3 $ip | Select-String -Pattern "平均").ToString() -replace '.*= (\d+)ms.*', '$1'
    if ($avg) { $results += [PSCustomObject]@{ IP = $ip; Avg = [int]$avg } }
}
$fastest = ($results | Sort-Object Avg | Select-Object -First 1).IP

# Update hosts
$entry = "$fastest github.com`n$fastest api.github.com"
$current = Get-Content $hostsPath -Raw -ErrorAction SilentlyContinue
if ($current -notmatch "github\.com") {
    Add-Content -Path $hostsPath -Value $entry
} else {
    $updated = $current -replace "[\d\.]+\s+github\.com`n?[\d\.]+\s+api\.github\.com", $entry
    Set-Content -Path $hostsPath -Value $updated
}

# Flush DNS
ipconfig /flushdns | Out-Null
Write-Host "Done! Fastest IP: $fastest"

Key Notes

• Hosts file requires Administrator privileges to modify
• If direct edit fails, output the entry and instruct user to manually add it
• The fastest IP may change over time; re-run when GitHub access slows again