diff --git a/e2e/localdns/validate-localdns-exporter-metrics.sh b/e2e/localdns/validate-localdns-exporter-metrics.sh
index 65f2cd83a53..35b62a07c6b 100644
--- a/e2e/localdns/validate-localdns-exporter-metrics.sh
+++ b/e2e/localdns/validate-localdns-exporter-metrics.sh
@@ -34,13 +34,14 @@ echo ""
 
 # Check if socket is listening
 echo "1. Checking if port 9353 is listening..."
-if ! ss -tln | grep -q ':9353[[:space:]]'; then
+SS_LISTEN_OUTPUT=$(ss -tln)
+if ! grep -q ':9353[[:space:]]' <<< "$SS_LISTEN_OUTPUT"; then
     echo "   ❌ ERROR: Port 9353 not listening"
-    ss -tln | grep -E ':(9353|53)[[:space:]]' || true
+    grep -E ':(9353|53)[[:space:]]' <<< "$SS_LISTEN_OUTPUT" || true
     exit 1
 fi
 # Detect the actual listen address (may be node IP via CSE drop-in, not 127.0.0.1)
-LISTEN_ADDR=$(ss -tln | grep ':9353[[:space:]]' | awk '{print $4}' | head -1)
+LISTEN_ADDR=$(awk '/:9353[[:space:]]/ {print $4; exit}' <<< "$SS_LISTEN_OUTPUT")
 LISTEN_ADDR=${LISTEN_ADDR//\*/127.0.0.1}
 LISTEN_ADDR=${LISTEN_ADDR//0.0.0.0/127.0.0.1}
 echo "   ✓ Port 9353 is listening on ${LISTEN_ADDR}"
@@ -101,26 +102,29 @@ fi
 echo "   ✓ Metrics fetched successfully"
 echo ""
 
+# Use here-strings when inspecting shell variables. With pipefail enabled,
+# `echo "$METRICS" | grep -q ...` can return a false negative if grep exits
+# early and the writer gets SIGPIPE on a large metrics payload.
 # Validate CPU usage metric — check data line exists and value is a valid number.
 echo "5. Validating CPU usage metric..."
-CPU_LINE=$(echo "$METRICS" | grep -E "^localdns_cpu_usage_seconds_total " || true)
+CPU_LINE=$(grep -E "^localdns_cpu_usage_seconds_total " <<< "$METRICS" || true)
 if [ -z "$CPU_LINE" ]; then
     echo "   ❌ ERROR: Missing localdns_cpu_usage_seconds_total data point"
     echo "   (found only comments/metadata or metric not present at all)"
-    echo "$METRICS" | grep "localdns_cpu" || true
+    grep "localdns_cpu" <<< "$METRICS" || true
     exit 1
 fi
-CPU_VALUE=$(echo "$CPU_LINE" | awk '{print $2}')
+CPU_VALUE=$(awk '{print $2}' <<< "$CPU_LINE")
 echo "   Raw metric: $CPU_LINE"
 echo "   Value: $CPU_VALUE"
 
-if ! echo "$CPU_VALUE" | grep -Eq '^[0-9]+\.?[0-9]*(e[+-]?[0-9]+)?$'; then
+if ! grep -Eq '^[0-9]+\.?[0-9]*(e[+-]?[0-9]+)?$' <<< "$CPU_VALUE"; then
     echo "   ❌ ERROR: CPU metric value is not a valid non-negative number: $CPU_VALUE"
     exit 1
 fi
 # Verify the exporter reports a non-zero CPU value — confirms the resources.prom pipeline is working
 # (localdns.sh writes real systemd cgroup data to the .prom file, exporter reads it)
-if echo "$CPU_VALUE" | grep -Eq '^0+(\.0+)?$'; then
+if grep -Eq '^0+(\.0+)?$' <<< "$CPU_VALUE"; then
     echo "   ❌ ERROR: Exported CPU metric is zero ($CPU_VALUE) — resources.prom pipeline may be broken"
     echo "   Raw systemd CPUUsageNSec was $RAW_CPU_NS (from step 2)"
     exit 1
@@ -130,23 +134,23 @@ echo ""
 
 # Validate memory usage metric — check data line exists and value is a valid number.
 echo "6. Validating memory usage metric..."
-MEM_LINE=$(echo "$METRICS" | grep -E "^localdns_memory_usage_bytes " || true)
+MEM_LINE=$(grep -E "^localdns_memory_usage_bytes " <<< "$METRICS" || true)
 if [ -z "$MEM_LINE" ]; then
     echo "   ❌ ERROR: Missing localdns_memory_usage_bytes data point"
     echo "   (found only comments/metadata or metric not present at all)"
-    echo "$METRICS" | grep "localdns_memory" || true
+    grep "localdns_memory" <<< "$METRICS" || true
     exit 1
 fi
-MEM_VALUE=$(echo "$MEM_LINE" | awk '{print $2}')
+MEM_VALUE=$(awk '{print $2}' <<< "$MEM_LINE")
 echo "   Raw metric: $MEM_LINE"
 echo "   Value: $MEM_VALUE"
 
-if ! echo "$MEM_VALUE" | grep -Eq '^[0-9]+\.?[0-9]*(e[+-]?[0-9]+)?$'; then
+if ! grep -Eq '^[0-9]+\.?[0-9]*(e[+-]?[0-9]+)?$' <<< "$MEM_VALUE"; then
     echo "   ❌ ERROR: Memory metric value is not a valid non-negative number: $MEM_VALUE"
     exit 1
 fi
 # Verify the exporter reports a non-zero memory value — confirms the resources.prom pipeline is working
-if echo "$MEM_VALUE" | grep -Eq '^0+(\.0+)?$'; then
+if grep -Eq '^0+(\.0+)?$' <<< "$MEM_VALUE"; then
     echo "   ❌ ERROR: Exported memory metric is zero ($MEM_VALUE) — resources.prom pipeline may be broken"
     echo "   Raw systemd MemoryCurrent was $RAW_MEM_BYTES (from step 2)"
     exit 1
@@ -156,13 +160,13 @@ echo ""
 
 # Validate staleness timestamp metric — check data line exists and value is a valid recent timestamp.
 echo "6b. Validating metrics staleness timestamp..."
-TIMESTAMP_LINE=$(echo "$METRICS" | grep -E "^localdns_metrics_last_update_timestamp_seconds " || true)
+TIMESTAMP_LINE=$(grep -E "^localdns_metrics_last_update_timestamp_seconds " <<< "$METRICS" || true)
 if [ -z "$TIMESTAMP_LINE" ]; then
     echo "   ❌ ERROR: Missing localdns_metrics_last_update_timestamp_seconds data point"
-    echo "$METRICS" | grep "localdns_metrics" || true
+    grep "localdns_metrics" <<< "$METRICS" || true
     exit 1
 fi
-TIMESTAMP_VALUE=$(echo "$TIMESTAMP_LINE" | awk '{print $2}')
+TIMESTAMP_VALUE=$(awk '{print $2}' <<< "$TIMESTAMP_LINE")
 echo "   Raw metric: $TIMESTAMP_LINE"
 CURRENT_TIME=$(date +%s)
 # Timestamp should be within the last 120 seconds (2 watchdog cycles)
@@ -176,20 +180,20 @@ echo ""
 
 # Check for VnetDNS forward IP metric
 echo "7. Validating VnetDNS forward IP metric..."
-if ! echo "$METRICS" | grep -q "localdns_vnetdns_forward_info"; then
+if ! grep -q "localdns_vnetdns_forward_info" <<< "$METRICS"; then
     echo "   ❌ ERROR: Missing localdns_vnetdns_forward_info"
     echo "   Available metrics:"
-    echo "$METRICS" | grep "^localdns_" | head -10
+    awk '/^localdns_/ { print; if (++count == 10) exit }' <<< "$METRICS"
     exit 1
 fi
 echo "   ✓ VnetDNS forward metric present"
 
 # Check for KubeDNS forward IP metric
 echo "8. Validating KubeDNS forward IP metric..."
-if ! echo "$METRICS" | grep -q "localdns_kubedns_forward_info"; then
+if ! grep -q "localdns_kubedns_forward_info" <<< "$METRICS"; then
     echo "   ❌ ERROR: Missing localdns_kubedns_forward_info"
     echo "   Available metrics:"
-    echo "$METRICS" | grep "^localdns_" | head -10
+    awk '/^localdns_/ { print; if (++count == 10) exit }' <<< "$METRICS"
     exit 1
 fi
 echo "   ✓ KubeDNS forward metric present"
@@ -207,7 +211,7 @@ validate_forward_metrics() {
 
     # Get all data lines (not comments) for this metric
     local data_lines
-    data_lines=$(echo "$METRICS" | grep "^${metric_name}{" || true)
+    data_lines=$(grep "^${metric_name}{" <<< "$METRICS" || true)
     if [ -z "$data_lines" ]; then
         echo "   ❌ ERROR: No data lines found for ${metric_name}" >&2
         exit 1
@@ -219,9 +223,9 @@ validate_forward_metrics() {
 
     # Check the first line to determine overall status
     local first_line
-    first_line=$(echo "$data_lines" | head -n 1)
+    first_line=$(sed -n '1p' <<< "$data_lines")
     local first_status
-    first_status=$(echo "$first_line" | sed -n 's/.*status="\([^"]*\)".*/\1/p')
+    first_status=$(sed -n 's/.*status="\([^"]*\)".*/\1/p' <<< "$first_line")
 
     if [ "$first_status" = "ok" ]; then
         # Validate every "ok" line has valid ip, block, and value
@@ -229,10 +233,10 @@ validate_forward_metrics() {
         while IFS= read -r line; do
             line_num=$((line_num + 1))
             local ip status block value
-            ip=$(echo "$line" | sed -n 's/.*ip="\([^"]*\)".*/\1/p')
-            status=$(echo "$line" | sed -n 's/.*status="\([^"]*\)".*/\1/p')
-            block=$(echo "$line" | sed -n 's/.*block="\([^"]*\)".*/\1/p')
-            value=$(echo "$line" | awk '{print $NF}')
+            ip=$(sed -n 's/.*ip="\([^"]*\)".*/\1/p' <<< "$line")
+            status=$(sed -n 's/.*status="\([^"]*\)".*/\1/p' <<< "$line")
+            block=$(sed -n 's/.*block="\([^"]*\)".*/\1/p' <<< "$line")
+            value=$(awk '{print $NF}' <<< "$line")
 
             if [ "$status" != "ok" ]; then
                 echo "   ❌ ERROR: ${display_name} line $line_num has unexpected status: $status" >&2
@@ -242,7 +246,7 @@ validate_forward_metrics() {
                 echo "   ❌ ERROR: ${display_name} line $line_num status=ok but IP is missing or unknown" >&2
                 exit 1
             fi
-            if ! echo "$ip" | grep -Eq '^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+$'; then
+            if ! grep -Eq '^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+$' <<< "$ip"; then
                 echo "   ❌ ERROR: ${display_name} line $line_num IP is not a valid IPv4: $ip" >&2
                 exit 1
             fi
@@ -255,7 +259,7 @@ validate_forward_metrics() {
                 exit 1
             fi
             # Block should contain :53 (zone format from corefile)
-            if ! echo "$block" | grep -q ':53$'; then
+            if ! grep -q ':53$' <<< "$block"; then
                 echo "   ❌ ERROR: ${display_name} line $line_num block label does not end with :53: $block" >&2
                 exit 1
             fi
@@ -265,7 +269,7 @@ validate_forward_metrics() {
     elif [ "$first_status" = "missing" ]; then
         echo "   ⚠️  ${display_name} forward not configured in corefile (expected for some cluster configs)" >&2
         local value
-        value=$(echo "$first_line" | awk '{print $NF}')
+        value=$(awk '{print $NF}' <<< "$first_line")
         if [ "$value" != "0" ]; then
             echo "   ❌ ERROR: ${display_name} not configured but value is not 0" >&2
             exit 1
@@ -273,7 +277,7 @@ validate_forward_metrics() {
     elif [ "$first_status" = "file_missing" ]; then
         echo "   ⚠️  Forward IPs .prom file is missing (may occur during initial setup)" >&2
         local value
-        value=$(echo "$first_line" | awk '{print $NF}')
+        value=$(awk '{print $NF}' <<< "$first_line")
         if [ "$value" != "0" ]; then
             echo "   ❌ ERROR: File missing but value is not 0" >&2
             exit 1
@@ -300,17 +304,17 @@ echo ""
 echo "=== ✓ All LocalDNS Metrics Validation Checks Passed ==="
 if [ "$VNETDNS_STATUS" = "ok" ] && [ "$KUBEDNS_STATUS" = "ok" ]; then
     echo "VnetDNS forwards:"
-    echo "$METRICS" | grep "^localdns_vnetdns_forward_info{" | sed 's/^/  /'
+    sed -n '/^localdns_vnetdns_forward_info{/s/^/  /p' <<< "$METRICS"
     echo "KubeDNS forwards:"
-    echo "$METRICS" | grep "^localdns_kubedns_forward_info{" | sed 's/^/  /'
+    sed -n '/^localdns_kubedns_forward_info{/s/^/  /p' <<< "$METRICS"
 elif [ "$VNETDNS_STATUS" = "ok" ]; then
     echo "VnetDNS forwards:"
-    echo "$METRICS" | grep "^localdns_vnetdns_forward_info{" | sed 's/^/  /'
+    sed -n '/^localdns_vnetdns_forward_info{/s/^/  /p' <<< "$METRICS"
     echo "KubeDNS: forward not configured (expected)"
 elif [ "$KUBEDNS_STATUS" = "ok" ]; then
     echo "VnetDNS: forward not configured (expected)"
     echo "KubeDNS forwards:"
-    echo "$METRICS" | grep "^localdns_kubedns_forward_info{" | sed 's/^/  /'
+    sed -n '/^localdns_kubedns_forward_info{/s/^/  /p' <<< "$METRICS"
 else
     echo "Both VnetDNS and KubeDNS forward not configured (may be expected for cluster config)"
 fi