diff --git a/app/sovran_systemsos_web/static/js/domain-prereqs.js b/app/sovran_systemsos_web/static/js/domain-prereqs.js
new file mode 100644
index 0000000..436d504
--- /dev/null
+++ b/app/sovran_systemsos_web/static/js/domain-prereqs.js
@@ -0,0 +1,146 @@
+/* Sovran_SystemsOS Hub — Shared domain-prerequisite instructions.
+
+   SINGLE SOURCE OF TRUTH for the "you need a Njal.la domain + router port
+   forwarding" guidance that must read identically everywhere it appears:
+
+     • First-boot onboarding wizard (Server + Desktop role)
+       — onboarding.js step 3
+     • Feature-enable domain modal (Node role, and any role)
+       — features.js openDomainSetupModal()
+       (Lightning Wallet Connections / NWC, BTCPay Server, Haven, …)
+     • Domain reconfigure / troubleshooting modal
+       — features.js openDomainReconfigureModal()
+
+   Keep these three surfaces word-for-word consistent: always edit this
+   file, never fork the wording inline. Plain classic script (no modules) —
+   both templates load it with a plain <script> tag. */
+"use strict";
+
+/* Escape helper local to this file so it is self-contained on both pages. */
+function dpEsc(str) {
+  return String(str)
+    .replace(/&/g, "&amp;")
+    .replace(/</g, "&lt;")
+    .replace(/>/g, "&gt;")
+    .replace(/"/g, "&quot;")
+    .replace(/'/g, "&#39;");
+}
+
+/* ── "What you'll need" intro ──────────────────────────────────────
+   opts.serviceName — e.g. "Lightning Wallet Connections", or null for
+   the multi-service (onboarding) wording.
+   opts.hostExample — e.g. "lightning" → lightning.yourdomain.com */
+function renderDomainNeedsHtml(opts) {
+  var serviceName = opts.serviceName || null;
+  var hostExample = dpEsc(opts.hostExample || "myservice");
+  var html = "";
+
+  if (serviceName) {
+    html += "<p>To enable <strong>" + dpEsc(serviceName) + "</strong>, you'll need two things first:</p>";
+    html += '<ol style="margin:8px 0 0 16px;padding:0;line-height:1.7;">';
+    html += "<li><strong>A domain of your own from <a href=\"https://njal.la\" target=\"_blank\" rel=\"noopener noreferrer\" style=\"color:var(--accent-color);\">Njal.la</a></strong> "
+      + "— privacy-friendly, no personal details required, accepts Bitcoin. "
+      + dpEsc(serviceName) + " gets its own hostname: a subdomain (e.g. <code>" + hostExample + ".yourdomain.com</code>) "
+      + "or a separate domain — your choice. Subdomains are free, and one domain can have many.</li>";
+    html += "<li><strong>Access to your router</strong> — you'll forward ports <strong>80</strong> and <strong>443</strong> (TCP) "
+      + "to this computer once. All domain-based services share these two ports; "
+      + "they're required for HTTPS and SSL certificates.</li>";
+    html += "</ol>";
+  } else {
+    html += "<p><strong>Each service below needs two things set up:</strong></p>";
+    html += '<ol style="margin:8px 0 0 16px;padding:0;line-height:1.7;">';
+    html += "<li><strong>A domain of your own from <a href=\"https://njal.la\" target=\"_blank\" rel=\"noopener noreferrer\" style=\"color:var(--accent-color);\">Njal.la</a></strong> "
+      + "— privacy-friendly, no personal details required, accepts Bitcoin. "
+      + "Each service gets its own hostname: its own subdomain (e.g. <code>" + hostExample + ".yourdomain.com</code>) "
+      + "or a separate domain — your choice. Subdomains are free, and one domain can have many, "
+      + "so a single domain can serve every service.</li>";
+    html += "<li><strong>Access to your router</strong> — you'll forward ports <strong>80</strong> and <strong>443</strong> (TCP) "
+      + "to this computer once. All domain-based services share these two ports; "
+      + "they're required for HTTPS and SSL certificates.</li>";
+    html += "</ol>";
+  }
+  return html;
+}
+
+/* ── "How to set it up at Njal.la" steps ───────────────────────────
+   opts.hostExample — host part used in the examples (default "call").
+   opts.pasteHint   — where the curl command goes:
+                      "below" (single service) or "next to its service below"
+                      (onboarding, many services). */
+function renderNjallaStepsHtml(opts) {
+  var hostExample = dpEsc((opts && opts.hostExample) || "call");
+  var pasteHint = (opts && opts.pasteHint) || "below";
+  var html = "";
+
+  html += "<p style=\"margin-top:12px;\"><strong>How to set it up at Njal.la:</strong></p>";
+  html += '<ol style="margin:8px 0 0 16px;padding:0;line-height:1.7;">';
+  html += "<li>Create an account at <a href=\"https://njal.la\" target=\"_blank\" rel=\"noopener noreferrer\" style=\"color:var(--accent-color);\">https://njal.la</a> and buy a domain.</li>";
+  html += "<li>Add a <strong>Dynamic</strong> record for the hostname:"
+    + '<ul style="margin:4px 0 0 16px;padding:0;line-height:1.7;">'
+    + "<li>In the Njal.la <strong>Name</strong> field, type ONLY the host part — the word before your domain.<br>"
+    + "(For &quot;" + hostExample + ".yourdomain.com&quot; you&apos;d type just: <code>" + hostExample + "</code>.)<br>"
+    + "&#9888; Do NOT type the full domain here — Njal.la adds it automatically.</li>"
+    + "<li>Dedicating a whole separate domain to this service? Leave the Name field blank or use <code>@</code>.</li>"
+    + "</ul>"
+    + "</li>";
+  html += "<li>A Dynamic record has <strong>NO IP field</strong> — you don&apos;t enter an IP anywhere. "
+    + "It auto-fills once Sovran_SystemsOS runs the update command (on save, and again after every reboot).</li>";
+  html += "<li>Njal.la gives you a curl command, e.g.:<br>"
+    + '<code style="font-size:0.8em;">curl &quot;https://njal.la/update/?h=' + hostExample + '.yourdomain.com&amp;k=abc123&amp;auto&quot;</code><br>'
+    + "Copy it and paste it " + pasteHint + ".</li>";
+  html += "</ol>";
+  return html;
+}
+
+/* ── "One router task" port-forwarding box ─────────────────────────
+   opts.internalIp  — LAN IP string, or empty/null for generic wording.
+   opts.plural      — true for multi-service (onboarding) wording.
+   opts.includeSsh  — also mention port 22 for SSH (onboarding).
+   opts.extraNote   — extra sentence appended at the end (optional). */
+function renderRouterPortsHtml(opts) {
+  opts = opts || {};
+  var ipPart = opts.internalIp
+    ? " to this computer&rsquo;s internal IP <strong>" + dpEsc(opts.internalIp) + "</strong>"
+    : " to this computer&rsquo;s internal IP";
+  var serviceWord = opts.plural ? "services" : "service";
+
+  var html = "";
+  html += "🔌 <strong>One router task:</strong> in your router&rsquo;s <strong>port forwarding</strong> settings, "
+    + "forward port <strong>80 (TCP)</strong> and port <strong>443 (TCP)</strong>"
+    + ipPart + ". Use the <strong>same number for the internal and external port</strong>. "
+    + "This only needs to be done once — all domain services share these ports — "
+    + "but HTTPS and SSL certificates won&rsquo;t work without them, so your " + serviceWord + " "
+    + "can&rsquo;t be reached from outside your home network. "
+    + "You&rsquo;ll need normal access to your router&rsquo;s settings with working port forwarding — "
+    + "if your ISP blocks it (e.g. CGNAT), domain-based services can&rsquo;t be reached from the internet. ";
+  if (opts.includeSsh) {
+    html += "Add port <strong>22 (TCP)</strong> as well if you want remote SSH access. ";
+  }
+  if (opts.extraNote) {
+    html += dpEsc(opts.extraNote);
+  }
+  return html;
+}
+
+/* ── Async helper: fill a router-box container with the internal IP ──
+   Renders generic text immediately, then upgrades to the concrete LAN IP
+   if /api/network provides one. Best-effort — never blocks the UI. */
+function renderRouterPortsBox(elId, opts) {
+  var el = document.getElementById(elId);
+  if (!el) return;
+  el.innerHTML = renderRouterPortsHtml(opts || {});
+  fetch("/api/network")
+    .then(function(r) { return r.json(); })
+    .then(function(data) {
+      var target = document.getElementById(elId);
+      if (!target) return;
+      var ip = data && data.internal_ip;
+      if (ip && ip !== "unavailable") {
+        var next = {};
+        for (var k in (opts || {})) next[k] = opts[k];
+        next.internalIp = String(ip).trim();
+        target.innerHTML = renderRouterPortsHtml(next);
+      }
+    })
+    .catch(function() { /* generic wording already shown — fine */ });
+}
diff --git a/app/sovran_systemsos_web/static/js/features.js b/app/sovran_systemsos_web/static/js/features.js
index 2863316..79082b0 100644
--- a/app/sovran_systemsos_web/static/js/features.js
+++ b/app/sovran_systemsos_web/static/js/features.js
@@ -86,45 +86,17 @@ function openDomainSetupModal(feat, onSaved) {
   var domainPlaceholder = isWalletConnections ? "lightning.yourdomain.com" : "myservice.example.com";
   var domainLabelExample = isWalletConnections ? "lightning.yourdomain.com" : "call.yourdomain.com";
 
-  var introHtml;
-  if (_currentRole === "node") {
-    introHtml =
-      '<p>To enable <strong>' + escHtml(feat.name) + '</strong>, it needs its own domain from Njal.la.</p>' +
-      '<ol style="margin:8px 0 0 16px;padding:0;line-height:1.7;">' +
-      '<li>Create an account at <a href="https://njal.la" target="_blank" rel="noopener noreferrer" style="color:var(--accent-color);">njal.la</a>.</li>' +
-      '<li>Set up a domain for it — either a free subdomain or a separate domain. Pick one option:</li>' +
-      '</ol>';
-  } else {
-    introHtml =
-      '<p>To enable <strong>' + escHtml(feat.name) + '</strong>, it needs its own domain from Njal.la. ' +
-      'In your Njal.la account, set up a domain for it — either a free subdomain or a separate domain. Pick one option:</p>';
-  }
+  // Shared instructions (single source of truth: static/js/domain-prereqs.js) —
+  // identical wording to the Server + Desktop onboarding wizard and every other
+  // domain-based feature, regardless of role (Node / Desktop / Server+Desktop).
+  var hostExample = isWalletConnections ? "lightning" : "call";
 
   $domainSetupBody.innerHTML =
     '<div class="domain-setup-intro">' +
     nwcWarning +
-    introHtml +
-    '<details style="margin-top:10px;">' +
-    '<summary style="cursor:pointer;font-weight:600;">Option A — Free subdomain (recommended)</summary>' +
-    '<ol style="margin:8px 0 0 16px;padding:0;line-height:1.7;">' +
-    '<li>In Njal.la, open a domain you own and click &quot;Add record&quot;.</li>' +
-    '<li>Set record type to <strong>Dynamic</strong>.</li>' +
-    '<li>In the <strong>Name</strong> field, type ONLY the host part — the word before your domain.<br>' +
-    '(Example only, your choice — for &quot;' + domainLabelExample + '&quot; you&apos;d type just: &nbsp;<code>' + (isWalletConnections ? 'lightning' : 'call') + '</code>)<br>' +
-    '&#9888; Do NOT type the full domain here — Njal.la adds it automatically.</li>' +
-    '<li>A Dynamic record has NO IP field — the IP auto-fills after the rebuild/reboot.</li>' +
-    '<li>Copy the curl command Njal.la gives you, e.g.:<br>' +
-    '<code style="font-size:0.8em;">curl &quot;https://njal.la/update/?h=' + domainLabelExample + '&amp;k=abc123&amp;auto&quot;</code></li>' +
-    '</ol>' +
-    '</details>' +
-    '<details style="margin-top:6px;">' +
-    '<summary style="cursor:pointer;font-weight:600;">Option B — Separate / new domain</summary>' +
-    '<ol style="margin:8px 0 0 16px;padding:0;line-height:1.7;">' +
-    '<li>In Njal.la, buy the domain you want.</li>' +
-    '<li>Add a Dynamic record as in Option A. If this domain is dedicated to the service, leave the Name field blank or use <code>@</code>.</li>' +
-    '<li>Copy the curl command Njal.la gives you.</li>' +
-    '</ol>' +
-    '</details>' +
+    renderDomainNeedsHtml({ serviceName: feat.name, hostExample: hostExample }) +
+    renderNjallaStepsHtml({ hostExample: hostExample, pasteHint: "below" }) +
+    '<div class="onboarding-port-warn" id="domain-router-box" style="margin-top:12px;"></div>' +
     '<p style="margin-top:10px;">Below, enter the full domain for this service — a subdomain (e.g. ' + domainLabelExample + ') or a separate domain — and paste its curl command.</p>' +
     '</div>' +
     '<div class="domain-field-group"><label class="domain-field-label" for="domain-subdomain-input">Service domain (e.g. ' + domainLabelExample + '):</label><input class="domain-field-input" type="text" id="domain-subdomain-input" placeholder="' + domainPlaceholder + '" /></div>' +
@@ -170,6 +142,9 @@ function openDomainSetupModal(feat, onSaved) {
   });
 
   $domainSetupModal.classList.add("open");
+
+  // Fill the router port-forwarding box with this computer's LAN IP (best-effort)
+  renderRouterPortsBox("domain-router-box");
 }
 
 function openDomainReconfigureModal(feat, existingDomain, onSaved) {
@@ -218,7 +193,9 @@ function openDomainReconfigureModal(feat, existingDomain, onSaved) {
     '<span style="display:inline-block;margin-top:4px;padding:4px 10px;background:var(--card-color);border:1px solid var(--border-color);border-radius:6px;font-family:monospace;font-size:1em;font-weight:700;">' + escHtml(externalIp) + '</span></li>' +
     '<li>If the IP is wrong or the record is missing, update it</li>' +
     '<li>If you changed the DDNS curl command, paste the updated one below</li>' +
+    '<li>Confirm ports <strong>80</strong> and <strong>443</strong> (TCP) are still forwarded on your router to this computer — see the reminder below:</li>' +
     '</ol>' +
+    '<div class="onboarding-port-warn" id="domain-router-box" style="margin-top:12px;"></div>' +
     '</div>' +
     '<div class="domain-field-group"><label class="domain-field-label" for="domain-subdomain-input">Service domain (e.g. ' + domainLabelExample + '):</label><input class="domain-field-input" type="text" id="domain-subdomain-input" placeholder="' + domainPlaceholder + '" value="' + escHtml(currentDomain) + '" /></div>' +
     '<div class="domain-field-group"><label class="domain-field-label" for="domain-ddns-input">Njal.la Dynamic DNS Update Command:</label><input class="domain-field-input" type="text" id="domain-ddns-input" placeholder="curl &quot;https://njal.la/update/?h=' + domainPlaceholder + '&amp;k=abc123&amp;auto&quot;" /><p class="domain-field-hint">ℹ Paste the full curl command from your Njal.la dashboard\'s Dynamic record</p></div>' +
@@ -263,6 +240,9 @@ function openDomainReconfigureModal(feat, existingDomain, onSaved) {
   });
 
   $domainSetupModal.classList.add("open");
+
+  // Fill the router port-forwarding box with this computer's LAN IP (best-effort)
+  renderRouterPortsBox("domain-router-box");
 }
 
 function closeDomainSetupModal() {
diff --git a/app/sovran_systemsos_web/static/onboarding.js b/app/sovran_systemsos_web/static/onboarding.js
index 998d827..5368b4b 100644
--- a/app/sovran_systemsos_web/static/onboarding.js
+++ b/app/sovran_systemsos_web/static/onboarding.js
@@ -357,38 +357,24 @@ async function loadStep3() {
   if (relevantDomains.length === 0) {
     html += '<p class="onboarding-body-text">No domain-based services are enabled for your role. You can skip this step.</p>';
   } else {
+    // Shared instructions (single source of truth: static/js/domain-prereqs.js) —
+    // identical wording to the feature-enable domain modal shown for NWC,
+    // BTCPay Server, and every other domain-based feature, in every role.
     html += '<div class="onboarding-port-warn" style="margin-bottom:16px;">'
-      + '<p style="margin:0 0 8px;"><strong>Sovran_SystemsOS uses Njal.la for domains and Dynamic DNS.</strong></p>'
-      + '<ol style="margin:8px 0 0 16px; padding:0; line-height:1.7;">'
-      + '<li>Create an account at <a href="https://njal.la" target="_blank" style="color:var(--accent-color);">https://njal.la</a>.</li>'
-      + '<li>Buy at least one domain. Each service below needs its own domain — you can either give each service its own subdomain of a single domain you buy (subdomains are free, and one domain can have many), OR use a separate domain for each. Your choice.</li>'
-      + '<li>For each service, add a <strong>Dynamic</strong> record in Njal.la:'
-      + '<ul style="margin:4px 0 0 16px;padding:0;line-height:1.7;">'
-      + '<li>In the Njal.la <strong>Name</strong> field, type ONLY the host part — the word before your domain.<br>'
-      + '(Example only, your choice — for &quot;call.yourdomain.com&quot; you&apos;d type just: <code>call</code>.)<br>'
-      + 'If you bought a whole separate domain just for this service, leave Name blank or use <code>@</code>.<br>'
-      + '&#9888; Do NOT type the full domain in the Name field — Njal.la adds it automatically.</li>'
-      + '<li>A Dynamic record has NO IP field. You don&apos;t enter an IP anywhere — it auto-fills once Sovran_SystemsOS updates it (on save, and again after reboot).</li>'
-      + '</ul>'
-      + '</li>'
-      + '<li>Njal.la gives you a curl command like:<br>'
-      + '<code style="font-size:0.8em;">curl &quot;https://njal.la/update/?h=call.yourdomain.com&amp;k=abc123&amp;auto&quot;</code></li>'
-      + '</ol>'
+      + renderDomainNeedsHtml({ serviceName: null, hostExample: "call" })
+      + renderNjallaStepsHtml({ hostExample: "call", pasteHint: "next to its service below" })
       + '</div>';
     html += '<p class="onboarding-hint">Enter each service\'s full domain — a subdomain (e.g. <code>call.yourdomain.com</code>) or a separate domain (e.g. <code>call.com</code>) — and its Njal.la DDNS curl command.</p>';
 
-    // Compact router note (full port guidance is shown when a feature is
-    // enabled, and lives on each service tile afterwards)
-    var routerIpPart = internalIp
-      ? ' to this computer&rsquo;s internal IP <strong>' + escHtml(internalIp) + '</strong>'
-      : ' to this computer&rsquo;s internal IP';
+    // Router note (the same wording is shown again, per-service, whenever a
+    // domain-based feature is enabled, and lives on each service tile afterwards)
     html += '<div class="onboarding-port-warn" style="margin-bottom:16px;">'
-      + '🔌 <strong>One router task:</strong> in your router&rsquo;s <strong>port forwarding</strong> settings, forward '
-      + 'port <strong>80 (TCP)</strong> and port <strong>443 (TCP)</strong>'
-      + routerIpPart + '. Use the <strong>same number for the internal and external port</strong>. '
-      + 'These are required for HTTPS and SSL certificates — without them your services cannot be reached from outside your home network. '
-      + 'Add port <strong>22 (TCP)</strong> as well if you want remote SSH access. '
-      + 'Element Call needs a few extra ports (some UDP), and you&rsquo;ll be shown exactly which when you enable it.'
+      + renderRouterPortsHtml({
+          internalIp: internalIp,
+          plural: true,
+          includeSsh: true,
+          extraNote: "Element Call needs a few extra ports (some UDP), and you’ll be shown exactly which when you enable it.",
+        })
       + '</div>';
 
     relevantDomains.forEach(function(d) {
diff --git a/app/sovran_systemsos_web/templates/index.html b/app/sovran_systemsos_web/templates/index.html
index 4b80669..555120b 100644
--- a/app/sovran_systemsos_web/templates/index.html
+++ b/app/sovran_systemsos_web/templates/index.html
@@ -312,6 +312,7 @@
   <script src="/static/js/constants.js?v={{ asset_version }}"></script>
   <script src="/static/js/state.js?v={{ asset_version }}"></script>
   <script src="/static/js/helpers.js?v={{ asset_version }}"></script>
+  <script src="/static/js/domain-prereqs.js?v={{ asset_version }}"></script>
   <script src="/static/js/tiles.js?v={{ asset_version }}"></script>
   <script src="/static/js/service-detail.js?v={{ asset_version }}"></script>
   <script src="/static/js/support.js?v={{ asset_version }}"></script>
diff --git a/app/sovran_systemsos_web/templates/onboarding.html b/app/sovran_systemsos_web/templates/onboarding.html
index 2048436..e009ad7 100644
--- a/app/sovran_systemsos_web/templates/onboarding.html
+++ b/app/sovran_systemsos_web/templates/onboarding.html
@@ -125,9 +125,8 @@
           <span class="onboarding-step-icon">🌐</span>
           <h2 class="onboarding-step-title">Domain Configuration</h2>
           <p class="onboarding-step-desc">
-            Sovran_SystemsOS uses <strong><a href="https://njal.la" target="_blank" style="color: var(--accent-color);">Njal.la</a></strong> for domains and Dynamic DNS.
-            Create an account at Njal.la, then for each service below, add a <strong>Dynamic</strong> record — no IP needed, it auto-populates once the DDNS curl command runs.
-            Paste the curl command from your Njal.la dashboard for each service.
+            Sovran_SystemsOS uses <strong><a href="https://njal.la" target="_blank" style="color: var(--accent-color);">Njal.la</a></strong> for domains and Dynamic DNS, and your router needs ports <strong>80</strong> and <strong>443</strong> (TCP) forwarded to this computer.
+            Everything you need — Njal.la account, Dynamic records, and the one router task — is laid out step by step below.
           </p>
         </div>
         <div class="onboarding-card" id="step-3-body">
@@ -170,6 +169,7 @@
     </div><!-- /panel-wrap -->
   </div><!-- /shell -->
 
+  <script src="/static/js/domain-prereqs.js?v={{ asset_version }}"></script>
   <script src="/static/onboarding.js?v={{ onboarding_js_hash }}"></script>
 </body>
 </html>