diff --git a/build_nid_viewer.py b/build_nid_viewer.py
index 3e00a89..7393862 100644
--- a/build_nid_viewer.py
+++ b/build_nid_viewer.py
@@ -734,6 +734,9 @@ function formatUptime(sec) {{
   p.push(s+'s');
   return p.join(' ');
 }}
+// SNMP TruthValue: some agents return '1'/'2', others 'true'/'false'
+function isTrue(v) {{ return v === '1' || v === 'true' || v === true; }}
+
 // Derive data ports and management port from connectors dynamically
 function getPortLists() {{
   const connectors = DATA.connectors || {{}};
@@ -990,7 +993,7 @@ function renderHeader() {{
   const cfgByNum = {{}};
   for (const [k,v] of Object.entries(alarmCfg)) cfgByNum[v.number] = v;
   for (const [k,a] of Object.entries(alarmStatus)) {{
-    if (a.active === '1') {{
+    if (isTrue(a.active)) {{
       activeCount++;
       const cfg = cfgByNum[a.number];
       if (cfg) sevCounts[cfg.severity] = (sevCounts[cfg.severity]||0) + 1;
@@ -1137,7 +1140,7 @@ function renderPanel() {{
     const iface = ifaces[connIdx];
     if (connType(connIdx) === 'sfp') {{
       const sfp = sfpInfo[connIdx];
-      const present = sfp && sfp.present === '1';
+      const present = sfp && isTrue(sfp.present);
       if (!present) return 'empty';
       if (iface && isUp(iface.ifOperStatus)) return 'present-link';
       return 'present-nolink';
@@ -1152,7 +1155,7 @@ function renderPanel() {{
   function sfpLabel(connIdx) {{
     const sfp = sfpInfo[connIdx];
     if (!sfp) return '';
-    if (sfp.present !== '1') return 'EMPTY';
+    if (!isTrue(sfp.present)) return 'EMPTY';
     const pn = sfp.vendorPn || '';
     if (pn.length > 8) return pn.substring(0,8);
     return pn || sfp.vendor || '';
@@ -1214,7 +1217,7 @@ function renderPanel() {{
   // Power feeds
   let pwrHtml = '<div class="pwr-block">';
   for (const [k,p] of Object.entries(pwr)) {{
-    const ok = p.present === '1';
+    const ok = isTrue(p.present);
     pwrHtml += `<div><span class="pwr-led ${{ok?'ok':'fail'}}"></span>${{esc(p.name)}} ${{ok?'OK':'ABSENT'}}</div>`;
   }}
   pwrHtml += '</div>';
@@ -1336,7 +1339,7 @@ function renderSfp() {{
     const thresh = sfpThresh[si] || {{}};
     const conn = connectors[si] || {{}};
 
-    if (!info || info.present !== '1') {{
+    if (!info || !isTrue(info.present)) {{
       cards += `<div class="sfp-detail" id="sfp-detail-${{si}}">
         <div class="card-dark" style="border-left:3px solid #555">
           <div class="card-body" style="text-align:center;color:#555;padding:2rem">
@@ -1348,7 +1351,7 @@ function renderSfp() {{
       continue;
     }}
 
-    const ddm = info.diagCapable === '1';
+    const ddm = isTrue(info.diagCapable);
     const ddmBadge = ddm
       ? '<span class="badge bg-success">DDM Supported</span>'
       : '<span class="badge bg-secondary">DDM Not Supported</span>';
@@ -1405,8 +1408,8 @@ function renderSfp() {{
               <h6 style="font-size:0.8rem;color:var(--text-muted)">CAPABILITIES</h6>
               <div style="font-size:0.82rem">
                 <div>DDM Capable: <strong>${{ddm ? 'Yes' : 'No'}}</strong></div>
-                <div>Internal Cal: <strong>${{info.internalCal==='1' ? 'Yes' : 'No'}}</strong></div>
-                <div>Alarm Capable: <strong>${{info.alarmCapable==='1' ? 'Yes' : 'No'}}</strong></div>
+                <div>Internal Cal: <strong>${{isTrue(info.internalCal) ? 'Yes' : 'No'}}</strong></div>
+                <div>Alarm Capable: <strong>${{isTrue(info.alarmCapable) ? 'Yes' : 'No'}}</strong></div>
                 <div>SFF-8472 Rev: <strong>${{esc(info.rev8472)}}</strong></div>
                 <div>ID Type: <strong>${{esc(info.idType)}}</strong></div>
                 <div>Ext ID: <strong>${{esc(info.extIdType)}}</strong></div>
@@ -1447,7 +1450,7 @@ function renderAlarms() {{
   // Collect active alarms (when status table available)
   const active = [];
   for (const [k,a] of Object.entries(alarmStatus)) {{
-    if (a.active === '1') {{
+    if (isTrue(a.active)) {{
       const cfg = cfgByNum[a.number] || {{}};
       active.push({{ ...a, ...cfg, _statusId: k }});
     }}
@@ -1489,7 +1492,7 @@ function renderAlarms() {{
         <td>${{esc(c.description)}}</td>`;
       if (hasSeverity) rows += `
         <td><span class="badge ${{sevClass(c.severity)}}">${{sevLabel(c.severity)}}</span></td>
-        <td>${{c.enabled === '1' ? '<span style="color:var(--green)">Yes</span>' : '<span style="color:var(--text-muted)">No</span>'}}</td>`;
+        <td>${{isTrue(c.enabled) ? '<span style="color:var(--green)">Yes</span>' : '<span style="color:var(--text-muted)">No</span>'}}</td>`;
       if (hasCondition) rows += `
         <td class="mono">${{esc(c.conditionType)}}</td>
         <td class="mono">${{esc(c.amoType)}}</td>`;
@@ -1636,12 +1639,12 @@ function renderFilters() {{
   let rows = '';
   for (const [id, f] of Object.entries(filters)) {{
     const conditions = [];
-    if (f.macDstEn === '1') conditions.push('MAC Dst: ' + esc(f.macDst));
-    if (f.macSrcEn === '1') conditions.push('MAC Src: ' + esc(f.macSrc));
-    if (f.etypeEn === '1') conditions.push('EType: ' + esc(f.etype));
-    if (f.vlan1IdEn === '1') conditions.push('VLAN1: ' + esc(f.vlan1Id));
-    if (f.vlan2IdEn === '1') conditions.push('VLAN2: ' + esc(f.vlan2Id));
-    if (f.vlan1PriorEn === '1') conditions.push('PCP1: ' + esc(f.vlan1Prior));
+    if (isTrue(f.macDstEn)) conditions.push('MAC Dst: ' + esc(f.macDst));
+    if (isTrue(f.macSrcEn)) conditions.push('MAC Src: ' + esc(f.macSrc));
+    if (isTrue(f.etypeEn)) conditions.push('EType: ' + esc(f.etype));
+    if (isTrue(f.vlan1IdEn)) conditions.push('VLAN1: ' + esc(f.vlan1Id));
+    if (isTrue(f.vlan2IdEn)) conditions.push('VLAN2: ' + esc(f.vlan2Id));
+    if (isTrue(f.vlan1PriorEn)) conditions.push('PCP1: ' + esc(f.vlan1Prior));
     const condStr = conditions.length ? conditions.join(', ') : '<span class="status-na">any (catchall)</span>';
 
     rows += `<tr>
@@ -1802,7 +1805,7 @@ function renderLldp() {{
     const iface = ifaces[portIdx];
     if (isSfp) {{
       const sfp = sfpInfo[portIdx];
-      const present = sfp && sfp.present === '1';
+      const present = sfp && isTrue(sfp.present);
       if (!present) return 'empty';
       if (iface && isUp(iface.ifOperStatus)) return 'present-link';
       return 'present-nolink';
@@ -2005,7 +2008,7 @@ function renderCoverage() {{
   // Check SFP DDM
   const sfpInfo = DATA.sfp_info || {{}};
   for (const [k,s] of Object.entries(sfpInfo)) {{
-    if (s.present === '1' && s.diagCapable !== '1') {{
+    if (isTrue(s.present) && !isTrue(s.diagCapable)) {{
       gaps.push({{
         type: 'red',
         text: `SFP-${{k}} DDM: Not available via SNMP (diagCapable=false). NID web UI reads SFP I2C bus directly.`