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Healthcheck an anycast DNS
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| #!/bin/bash | |
| function healthcheck() { | |
| local domain=$1 | |
| local total_tests=$2 | |
| local total_failed_count=0 | |
| local ip_list=() | |
| for ((i = 0; i < total_tests; i++)); do | |
| # DNS may returns multiple records, skip CNAMEs, take only the first one. | |
| local test_ip | |
| test_ip=$(dig +short "$domain" | grep -E '^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+$' | head -n 1) | |
| echo "Testing $test_ip" | |
| ip_list+=("$test_ip") | |
| if ! ping -c 1 -W 2 "$test_ip" &> /dev/null; then | |
| echo "Failed to connect: $test_ip" | |
| total_failed_count=$((total_failed_count + 1)) | |
| fi | |
| done | |
| echo | |
| echo "Total Tests: $total_tests" | |
| echo "Total Failed Tests: $total_failed_count" | |
| local failure_ratio | |
| failure_ratio=$(echo "scale=3; $total_failed_count / $total_tests * 100" | bc) | |
| printf "Failure Ratio: %.2f%%\n" "$failure_ratio" | |
| echo | |
| local unique_ip_list | |
| unique_ip_list=($(printf "%s\n" "${ip_list[@]}" | sort -u)) | |
| echo "Tested IPs:" | |
| for ip in "${unique_ip_list[@]}"; do | |
| echo "- $ip" | |
| done | |
| } | |
| healthcheck "vercel.com" 1000 |
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| #!/bin/bash | |
| ip_to_int() { | |
| local ip="$1" | |
| local a b c d | |
| IFS='.' read -r a b c d <<< "$ip" | |
| echo "$((a * 256 ** 3 + b * 256 ** 2 + c * 256 + d))" | |
| } | |
| int_to_ip() { | |
| local int="$1" | |
| echo "$((int >> 24 & 255)).$((int >> 16 & 255)).$((int >> 8 & 255)).$((int & 255))" | |
| } | |
| start_int=$(ip_to_int "76.76.21.1") | |
| end_int=$(ip_to_int "76.76.21.254") | |
| for ((ip_int = start_int; ip_int <= end_int; ip_int++)); do | |
| current_ip=$(int_to_ip "$ip_int") | |
| if ! ping -c 1 -W 2 "$current_ip" &> /dev/null; then | |
| echo "Failed: $current_ip" | |
| fi | |
| done |
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