Update dns_tester.sh

actual tests

dns_tester.sh

@@ -75,12 +75,15 @@ test_dns_performance() {
     local successful_tests=0
     local test_count=0
     
+    # Get the first IPv4 DNS server for testing
+    local primary_dns=$(echo "$dns_servers" | cut -d',' -f1)
+    
     IFS=',' read -ra TARGET_ARRAY <<< "$targets"
     for target in "${TARGET_ARRAY[@]}"; do
         target=$(echo "$target" | xargs)
         if [[ -n "$target" ]]; then
             test_count=$((test_count + 1))
-            local latency=$(ping_dns_resolved "$target" "$dns_servers" 2>/dev/null || echo "999")
+            local latency=$(measure_dns_query_time "$target" "$primary_dns" 2>/dev/null || echo "999")
             if [[ "$latency" != "999" ]]; then
                 total_latency=$((total_latency + latency))
                 successful_tests=$((successful_tests + 1))
@@ -90,16 +93,7 @@ test_dns_performance() {
     
     if [[ $successful_tests -gt 0 ]]; then
         local avg_latency=$((total_latency / successful_tests))
-        local simulated_latency=$avg_latency
+        RESULTS["$dns_name"]=$avg_latency
-        case $dns_name in
-            "Cloudflare") simulated_latency=$((avg_latency + 5)) ;;
-            "Google") simulated_latency=$((avg_latency + 8)) ;;
-            "Level3") simulated_latency=$((avg_latency + 12)) ;;
-            "OpenDNS") simulated_latency=$((avg_latency + 15)) ;;
-            "Quad9") simulated_latency=$((avg_latency + 18)) ;;
-            "Comodo") simulated_latency=$((avg_latency + 20)) ;;
-        esac
-        RESULTS["$dns_name"]=$simulated_latency
         DNS_NAMES["$dns_name"]="$dns_servers"
     else
         RESULTS["$dns_name"]=999
@@ -107,29 +101,50 @@ test_dns_performance() {
     fi
 }
 
-ping_dns_resolved() {
+measure_dns_query_time() {
     local target=$1
-    local dns_servers=$2
+    local dns_server=$2
     
-    local best_latency=999
+    local latency=999
     
-    local fallback_ip=$(nslookup "$target" 2>/dev/null | grep "Address:" | grep -v "::" | tail -1 | awk '{print $2}')
+    # Use dig to measure actual DNS query time
-    if [[ -z "$fallback_ip" ]]; then
+    if command -v dig &> /dev/null; then
-        fallback_ip=$(nslookup "$target" 2>/dev/null | grep "Address:" | tail -1 | awk '{print $2}')
+        # First verify the query works
-    fi
+        local dig_output=$(timeout 5 dig @"$dns_server" "$target" A +short 2>/dev/null)
+        if [[ -n "$dig_output" ]]; then
+            # Measure the actual query time
+            local start_time=$(date +%s%3N)
+            timeout 5 dig @"$dns_server" "$target" A +short >/dev/null 2>&1
+            local end_time=$(date +%s%3N)
+            latency=$(( (end_time - start_time) ))
             
-    if [[ -n "$fallback_ip" ]]; then
+            # Convert to milliseconds if needed
-        if [[ "$fallback_ip" == *":"* ]]; then
+            if [[ $latency -gt 1000 ]]; then
-            local latency=$(ping6 -c 1 -W 2 "$fallback_ip" 2>/dev/null | grep "time=" | cut -d'=' -f2 | cut -d' ' -f1 | cut -d'.' -f1)
+                latency=$(( latency / 1000 ))
-        else
+            fi
-            local latency=$(ping -c 1 -W 2 "$fallback_ip" 2>/dev/null | grep "time=" | cut -d'=' -f2 | cut -d' ' -f1 | cut -d'.' -f1)
         fi
-        if [[ -n "$latency" ]]; then
+    elif command -v nslookup &> /dev/null; then
-            best_latency=$latency
+        # Fallback to nslookup with timing
+        local start_time=$(date +%s%3N)
+        local nslookup_output=$(timeout 5 nslookup "$target" "$dns_server" 2>/dev/null)
+        local end_time=$(date +%s%3N)
+        
+        if echo "$nslookup_output" | grep -q "Address:"; then
+            latency=$(( (end_time - start_time) ))
+            
+            # Convert to milliseconds if needed
+            if [[ $latency -gt 1000 ]]; then
+                latency=$(( latency / 1000 ))
+            fi
         fi
     fi
     
-    echo "$best_latency"
+    # Ensure latency is reasonable (not negative or too high)
+    if [[ $latency -lt 0 || $latency -gt 5000 ]]; then
+        latency=999
+    fi
+    
+    echo "$latency"
 }
 
 run_tests() {
@@ -235,20 +250,23 @@ show_post_results_menu() {
 check_dependencies() {
     local missing_deps=()
     
-    if ! command -v ping &> /dev/null; then
+    if ! command -v dig &> /dev/null && ! command -v nslookup &> /dev/null; then
-        missing_deps+=("iputils-ping")
-    fi
-    
-    if ! command -v nslookup &> /dev/null && ! command -v dig &> /dev/null; then
         missing_deps+=("dnsutils or bind-utils")
     fi
     
     if [[ ${#missing_deps[@]} -gt 0 ]]; then
         echo -e "${RED}Missing dependencies: ${missing_deps[*]}${NC}"
         echo -e "${YELLOW}Please install them and run the script again.${NC}"
-        echo -e "${CYAN}Example: sudo apt install dnsutils iputils-ping${NC}"
+        echo -e "${CYAN}Example: sudo apt install dnsutils${NC}"
+        echo -e "${CYAN}Or: sudo yum install bind-utils${NC}"
         exit 1
     fi
+    
+    if command -v dig &> /dev/null; then
+        echo -e "${GREEN}Using dig for DNS queries (recommended)${NC}"
+    else
+        echo -e "${YELLOW}Using nslookup for DNS queries (dig preferred)${NC}"
+    fi
 }
 
 main() {
@@ -299,3 +317,4 @@ main() {
 }
 
 main "$@"
+