feat(fls): export the editor model's system software

exportProject.ts, step X2: a switch's SSID and learning time, a host's
SSID, manual routes, RIP, DHCP client and server with static assignments, a
home router's port forwarding, the firewall of a router or home router (the
core's names as Java's numbers), and modems. What the model has no setting
for is what Java's constructors make. A remote link pair becomes modems on
the port its identifier names (12345 when it names none); the first of a
pair in node order serves, the others connect to localhost.

Checked by Java: every corpus file, imported, exported and written, loads
with the system software of the original up to two new named departures: a
switch SSID Java rolls is the one the model derives from the node id, and
the model keeps a modem pair, not which one serves (modem_beispiel.fls has
the client first; both ways work within one project). The synthetic model
now has settings away from every default, a home router with port
forwarding and two modem pairs. 21 mutation probes, each loaded by Java,
were all caught.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

CHANGES.md

@@ -51,8 +51,8 @@ Swift-Pfade relativ zu `filius-ipad/ios/FiliusPad/TopologyEditor/` (Stand
 | `test/javaBeansWriter.test.ts`, `test/beans/` | — | neu: 11 Dateien des Schreibers, von Javas `XMLDecoder` gelesen und beschrieben; Erwartungen von Hand |
 | `src/topologyWriter.ts` | Java `SzenarioVerwaltung.netzwerkSpeichern`, Konstruktoren von `NetzwerkInterface`, `Port`, `GUIKabelItem` und der Systemsoftware | neu nach Java: `konfiguration.xml` aus Javas Sicht — Geräte, Schnittstellen (vom Konstruktor angelegte über Getter, weitere per `add`), Ports über Getter-Verweise, Kabel samt Zeichen-Enden (`kabelpanel`), Doku-Elemente; Systemsoftware über ihre Setter: SSID, Lernzeit, RIP, manuelle Routen, DHCP-Client und -Server, statische NAT, Modem, Router-Firewall (über das `konfig`-Plug-in des Webservers, wie XMLEncoder sie erreicht); Dateisysteme (an die Wurzel des Konstruktors angehängt wie bei XMLEncoder, beim Router hinter dessen Vorlagen); installierte Programme nach den Dateien (Webserver, Tauschbörse und E-Mail-Server legen ihre Ordner nur an, wo sie fehlen; der DNS-Server liest `/dns/hosts` beim Installieren), je unter ihrem Schlüssel mit der Systemsoftware wie `installApp`, samt Einstellungen und persönlicher Firewall; E-Mail: Domain und Bean-Konten des Servers samt Postfächern, Ordner und Adressbuch des Clients (sein Konto steht in `/konten.txt`, einer Datei); Javas Fehler nicht übernommen: ein Empfänger, den eine ältere Datei als Zeichenkette hält, wird als der `AddressEntry` geschrieben, den Javas `AddressEntry(String)` daraus macht (Java legt die Zeichenkette ungeprüft in die typisierte Liste, sein E-Mail-Fenster scheitert daran), ein `null`-Empfänger fällt weg; Kopf „Filius version: 2.14.0 (mdg-filius)“ |
 | `test/topologyWriter.test.ts`, `test/written.java.json` | — | neu: alle 23 Korpus-Dateien gelesen und neu geschrieben, von Java geladen — Topologie, Systemsoftware, Dateisysteme und Programme samt E-Mail wie beim Original (bis auf die benannte Abweichung bei Empfängern als Zeichenkette, nur in `man-in-the-middle.fls`) (Java gegen Java); dazu eine künstliche Topologie mit dem, was der Korpus nicht hat (u. a. eingeschaltete Router-Firewall mit Regeln jedes Protokolls, alle Firewall-Schalter abseits der Vorgabe, Modem mit eigenem Port und Ziel, verschachtelter Dateibaum mit umbenannter Wurzel, namenlosem Ordner, Datei ohne Typ und Inhalt mit CR/CRLF und Zeichen jenseits der BMP, Heimrouter mit eigener Wurzel, jedes Filius-Programm mit Einstellungen abseits der Vorgabe samt persönlicher Firewall, von Java angelegte Ordner `/peer2peer` und `/mailserver`, E-Mail-Server und -Client mit Konto, Postfach, drei Ordnern, Adressbuch und Empfängern aller Formen) |
-| `src/exportProject.ts` | Gegenstück zu `importProject.ts`; Java `JHostKonfiguration.updateWifiConnection`, `InternetKnotenBetriebssystem.getStandardGateway`/`setStandardGateway` | neu: Editor-Modell → Javas Sicht für den Schreiber, Schritt X1 Topologie — Geräte, Schnittstellen (MAC wie in der Simulation: aus der Datei oder aus der Port-ID abgeleitet), Kabel samt Funk (Karte drahtlos und Switch, wie Java verbindet), Gateway und DNS an allen Schnittstellen wie Javas eigene Setter, Doku-Elemente |
-| `test/exportProject.test.ts`, `test/exported.java.json` | — | neu: alle 23 Korpus-Dateien importiert, exportiert, geschrieben und von Java geladen — Topologie wie beim Original bis auf benannte Abweichungen (abgeleiteter MAC statt gewürfeltem, Doku in Zeichenreihenfolge mit Text, Schrift und Mindestgröße des Modells); dazu ein künstliches Modell, das Java ebenfalls lädt |
+| `src/exportProject.ts` | Gegenstück zu `importProject.ts`; Java `JHostKonfiguration.updateWifiConnection`, `InternetKnotenBetriebssystem.getStandardGateway`/`setStandardGateway` | neu: Editor-Modell → Javas Sicht für den Schreiber, Schritt X1 Topologie — Geräte, Schnittstellen (MAC wie in der Simulation: aus der Datei oder aus der Port-ID abgeleitet), Kabel samt Funk (Karte drahtlos und Switch, wie Java verbindet), Gateway und DNS an allen Schnittstellen wie Javas eigene Setter, Doku-Elemente; X2 Systemsoftware — SSIDs, Lernzeit, Routen, RIP, DHCP-Client und -Server, Portweiterleitung, Firewall (Namen des Kerns als Javas Zahlen), Modems aus den Paaren des Modells (Port aus dem Paarnamen, der erste eines Paars dient, Ziel `localhost`) |
+| `test/exportProject.test.ts`, `test/exported.java.json` | — | neu: alle 23 Korpus-Dateien importiert, exportiert, geschrieben und von Java geladen — Topologie wie beim Original bis auf benannte Abweichungen (abgeleiteter MAC und abgeleitete Switch-SSID statt gewürfelter, Modem-Rollen nach Reihenfolge im Paar, Doku in Zeichenreihenfolge mit Text, Schrift und Mindestgröße des Modells); dazu ein künstliches Modell, das Java ebenfalls lädt |
 | `src/importEmail.ts` | `Persistence/TopologyProjectStore.swift` (`registerJavaEmailConfigurations`, `assignedJavaEmailMessages`) | übertragen, Eingabe ist Javas Sicht: Server-Konten aus `/mailserver/konten.txt`, ohne Datei aus der Bean-Liste (Java verlöre sie); Client-Konto aus `/konten.txt`, ohne Datei aus der älteren `kontoListe` (Filius 2.14 liest sie nicht mehr); Konten und Nachrichten bleiben, wo Swift verwirft, was seine Prüfung nicht besteht; Vor- und Nachname getrennt; Empfangszeit nur aus der Datei (Swift nummeriert); gegen Swifts Modell geprüft |
 | `test/importEmail.test.ts`, `test/email-*.swift.json` | `State/TopologyEmail.swift` (`decodeJavaServer`, `decodeJavaClient`) als Vergleich | neu: dieselben 43 Kontodateien mit Swifts Leser; wie Swift bis auf benannte Fälle, in denen Swift prüft und die ganze Datei verwirft, wo Java liest |
 | `src/javaFileSystem.ts`, `src/javaString.ts` | Java `Dateisystem.holeDatei`, `String.trim`/`split`/`equalsIgnoreCase` | neu nach Java; die Groß-/Kleinschreibung gegenüber ASCII am JDK über die ganze BMP gemessen |

packages/fls/src/exportProject.ts

@@ -7,7 +7,15 @@
 // becomes a cable between those, drawn between its two nodes; each
 // documentation item a GUIDocuItem. A host whose wireless is enabled has a
 // wireless card, and its link to a switch is a wireless cable — the only
-// wireless connection Java makes (JHostKonfiguration.updateWifiConnection). System software, files and programs
+// wireless connection Java makes (JHostKonfiguration.updateWifiConnection).
+//
+// The system software: a switch's SSID and learning time, a host's SSID,
+// manual routes, RIP, DHCP client and server, a home router's port
+// forwarding, the firewall of a router or home router, and a modem. What the
+// model has no setting for is what Java's constructors make. A remote link
+// pair becomes modems on the port its identifier names (12345 when it names
+// none): the first of a pair in node order serves, the others connect to
+// localhost — the model's pairs live in one project. System software, files and programs
 // follow in later steps.
 //
 // What the model keeps is written as it keeps it, and so differs from the
@@ -21,15 +29,28 @@
 //    Java reads them from the first interface only (getStandardGateway,
 //    getDNSServer), and the model keeps no others;
 //  - a documentation item always has a text and a font, bold or plain: where
-//    Java has none, the empty text and Dialog 12 the model gives it.
+//    Java has none, the empty text and Dialog 12 the model gives it;
+//  - a switch's SSID the file lacked (Java rolls one) is the one the model
+//    derives from the node's id.
 //
 // Checked by Java: every corpus file, imported, exported and written, loads in
 // Java FILIUS to the topology of the original up to those departures.
 
 import {
+  defaultSwitchConfiguration,
+  dhcpServerConfiguration,
   effectiveMacAddress,
+  firewallConfiguration,
+  FIREWALL_PROTOCOL,
   interfaceKey,
   type DeviceConfiguration,
+  type DhcpClientConfiguration,
+  type DhcpServerConfiguration,
+  type FirewallConfiguration,
+  type GatewayPortForwardingRow,
+  type ManualRoute,
+  type RemoteLinkConfiguration,
+  type SwitchConfiguration,
   type DocumentationItem,
   type HostLabelPolicy,
   type HostWirelessConfiguration,
@@ -40,8 +61,9 @@ import {
   type TopologyGraph,
   type TopologyNode,
 } from '@mdg-filius/core';
+import type { FlsDhcpServer, FlsFirewall } from './systemSoftware.js';
 import type { FlsDocumentationItem, FlsInterface, FlsLink, FlsNodeClass } from './topology.js';
-import type { NodeToWrite, TopologyToWrite } from './topologyWriter.js';
+import type { NodeToWrite, SystemToWrite, TopologyToWrite } from './topologyWriter.js';
 
 /** The parts of the editor model the topology is made of. */
 export interface ProjectToExport {
@@ -49,6 +71,14 @@ export interface ProjectToExport {
   readonly deviceConfigurations: ReadonlyMap<Id, DeviceConfiguration>;
   readonly interfaceConfigurations: ReadonlyMap<InterfaceKey, InterfaceConfiguration>;
   readonly hostWirelessConfigurations: ReadonlyMap<Id, HostWirelessConfiguration>;
+  readonly switchConfigurations: ReadonlyMap<Id, SwitchConfiguration>;
+  readonly manualRoutesByNodeId: ReadonlyMap<Id, readonly ManualRoute[]>;
+  readonly ripEnabledByNodeId: ReadonlyMap<Id, boolean>;
+  readonly firewallConfigurationsByNodeId: ReadonlyMap<Id, FirewallConfiguration>;
+  readonly dhcpClientConfigurations: ReadonlyMap<Id, DhcpClientConfiguration>;
+  readonly dhcpServerConfigurations: ReadonlyMap<Id, DhcpServerConfiguration>;
+  readonly portForwardingRowsByNodeId: ReadonlyMap<Id, readonly GatewayPortForwardingRow[]>;
+  readonly remoteLinkConfigurations: ReadonlyMap<Id, RemoteLinkConfiguration>;
   readonly documentationItems: readonly DocumentationItem[];
 }
 
@@ -74,7 +104,8 @@ export function exportProject(project: ProjectToExport): ExportedTopology {
     return false;
   });
   const indexOfNode = new Map(exported.map((node, index) => [node.id, index]));
-  const nodes = exported.map((node) => exportNode(node, project));
+  const servingModems = firstOfEachPair(exported, project);
+  const nodes = exported.map((node) => exportNode(node, project, servingModems));
 
   const links: FlsLink[] = [];
   project.graph.links.forEach((link, index) => {
@@ -102,7 +133,7 @@ export function exportProject(project: ProjectToExport): ExportedTopology {
   };
 }
 
-function exportNode(node: TopologyNode, project: ProjectToExport): NodeToWrite {
+function exportNode(node: TopologyNode, project: ProjectToExport, servingModems: ReadonlySet<Id>): NodeToWrite {
   const javaClass = CLASS_OF_KIND[node.kind as Exclude<NodeKind, 'unsupported'>];
   const interfaces = exportInterfaces(node, project);
   return {
@@ -114,7 +145,119 @@ function exportNode(node: TopologyNode, project: ProjectToExport): NodeToWrite {
     useMacAsName: showsMac(node.hostLabelPolicy),
     interfaces,
     portCount: javaClass === 'Switch' || javaClass === 'Modem' ? node.ports.length : interfaces.length,
-    system: {},
+    system: exportSystem(node, project, servingModems),
+  };
+}
+
+/** The first node of each remote link pair: its modem serves. */
+function firstOfEachPair(nodes: readonly TopologyNode[], project: ProjectToExport): Set<Id> {
+  const seen = new Set<string>();
+  const serving = new Set<Id>();
+  for (const node of nodes) {
+    if (node.kind !== 'remoteLink') continue;
+    const pair = project.remoteLinkConfigurations.get(node.id)?.pairIdentifier ?? '';
+    if (seen.has(pair)) continue;
+    seen.add(pair);
+    serving.add(node.id);
+  }
+  return serving;
+}
+
+const JAVA_MODEM_PAIR = /^java-modem-port-([0-9]{1,5})$/;
+const DEFAULT_MODEM_PORT = 12_345;
+
+function modemPort(pairIdentifier: string | undefined): number {
+  const match = JAVA_MODEM_PAIR.exec(pairIdentifier ?? '');
+  const port = match === null ? DEFAULT_MODEM_PORT : Number(match[1]);
+  return port >= 1 && port <= 65_535 ? port : DEFAULT_MODEM_PORT;
+}
+
+function exportSystem(node: TopologyNode, project: ProjectToExport, servingModems: ReadonlySet<Id>): SystemToWrite {
+  const id = node.id;
+  switch (node.kind) {
+    case 'networkSwitch': {
+      const configuration = project.switchConfigurations.get(id) ?? defaultSwitchConfiguration(id);
+      return { ssid: configuration.ssid, retentionTime: configuration.retentionTimeMilliseconds };
+    }
+    case 'remoteLink':
+      return {
+        modem: {
+          mode: servingModems.has(id) ? 1 : 2,
+          port: modemPort(project.remoteLinkConfigurations.get(id)?.pairIdentifier),
+          ipAddress: 'localhost',
+        },
+      };
+    case 'unsupported':
+      return {};
+    default:
+      break;
+  }
+  const system: SystemToWrite = {
+    manualRoutes: (project.manualRoutesByNodeId.get(id) ?? []).map((route) => [
+      route.destinationNetwork,
+      route.subnetMask,
+      route.gateway,
+      route.interfaceIPAddress,
+    ]),
+    dhcpClient: project.dhcpClientConfigurations.get(id)?.isEnabled === true,
+    dhcpServer: exportDhcpServer(project.dhcpServerConfigurations.get(id) ?? dhcpServerConfiguration()),
+  };
+  switch (node.kind) {
+    case 'pc':
+    case 'notebook': {
+      const ssid = project.hostWirelessConfigurations.get(id)?.ssid ?? '';
+      return { ...system, ssid: ssid === '' ? null : ssid };
+    }
+    case 'router':
+      return {
+        ...system,
+        ripEnabled: project.ripEnabledByNodeId.get(id) === true,
+        firewall: exportFirewall(project.firewallConfigurationsByNodeId.get(id) ?? firewallConfiguration()),
+      };
+    case 'gateway':
+      return {
+        ...system,
+        staticNAT: (project.portForwardingRowsByNodeId.get(id) ?? []).map((row) => [
+          row.protocolValue,
+          row.publicPortValue,
+          row.lanIPAddress,
+          row.lanPortValue,
+        ]),
+        firewall: exportFirewall(project.firewallConfigurationsByNodeId.get(id) ?? firewallConfiguration()),
+      };
+  }
+}
+
+function exportDhcpServer(server: DhcpServerConfiguration): FlsDhcpServer {
+  return {
+    isActive: server.isActive,
+    lowerBound: server.lowerBoundIPAddress,
+    upperBound: server.upperBoundIPAddress,
+    gateway: server.gatewayIPAddress,
+    dnsServer: server.dnsServerIPAddress,
+    useOwnSettings: server.useOwnSettings,
+    staticAssignedAddresses: server.staticAssignments.map((entry) => ({ mac: entry.macAddress, ip: entry.ipAddress })),
+  };
+}
+
+/** The core's names as Java's numbers: FirewallRule.DROP = 0, ACCEPT = 1. */
+function exportFirewall(firewall: FirewallConfiguration): FlsFirewall {
+  const action = (value: 'drop' | 'accept') => (value === 'accept' ? 1 : 0);
+  return {
+    activated: firewall.isActive,
+    defaultPolicy: action(firewall.defaultPolicy),
+    dropICMP: firewall.dropIcmp,
+    filterSYNSegmentsOnly: firewall.filterSynSegmentsOnly,
+    filterUdp: firewall.filterUdp,
+    rules: firewall.rules.map((rule) => ({
+      srcIP: rule.sourceIPAddress,
+      srcMask: rule.sourceSubnetMask,
+      destIP: rule.destinationIPAddress,
+      destMask: rule.destinationSubnetMask,
+      port: rule.port,
+      protocol: FIREWALL_PROTOCOL[rule.protocol],
+      action: action(rule.action),
+    })),
   };
 }
 

packages/fls/test/exportProject.test.ts

@@ -11,7 +11,16 @@ import { createHash } from 'node:crypto';
 import { mkdirSync, readdirSync, readFileSync, statSync, writeFileSync } from 'node:fs';
 import { dirname, join, relative } from 'node:path';
 import { fileURLToPath } from 'node:url';
-import { DOCUMENTATION_MINIMUM_SIZE, stableGeneratedMacAddress, type Id, type TopologyNode } from '@mdg-filius/core';
+import {
+  defaultSwitchConfiguration,
+  dhcpServerConfiguration,
+  DOCUMENTATION_MINIMUM_SIZE,
+  firewallConfiguration,
+  firewallRule,
+  stableGeneratedMacAddress,
+  type Id,
+  type TopologyNode,
+} from '@mdg-filius/core';
 import { describe, expect, it } from 'vitest';
 import {
   decodeJavaBeans,
@@ -42,13 +51,27 @@ function counter(): () => Id {
   return () => `00000000-0000-0000-0000-${String(++next).padStart(12, '0')}`;
 }
 
-type JavaNode = { class: string; name: string | null; bounds: number[]; useIpAsName?: boolean; useMacAsName?: boolean; ports: unknown };
+type JavaNode = {
+  class: string;
+  name: string | null;
+  bounds: number[];
+  useIpAsName?: boolean;
+  useMacAsName?: boolean;
+  ports: unknown;
+  system: Record<string, unknown>;
+};
 type JavaFile = { success: boolean; nodes: JavaNode[]; cables: unknown[]; documentation: unknown[]; sha256?: string };
 
 const original = JSON.parse(readFileSync(join(corpusRoot, 'corpus.java.json'), 'utf8')) as Record<string, JavaFile>;
 const exportedPath = join(here, 'exported.java.json');
 const exported = JSON.parse(readFileSync(exportedPath, 'utf8')) as Record<string, JavaFile>;
 
+/** The system software without its files and applications, later steps. */
+function systemOf(system: Record<string, unknown>) {
+  const { fileSystem: _files, applications: _applications, ...settings } = system;
+  return settings;
+}
+
 /** The topology of Java's view: the label's position, not its size. */
 function topologyOf(view: JavaFile) {
   return {
@@ -60,6 +83,7 @@ function topologyOf(view: JavaFile) {
       useIpAsName: node.useIpAsName,
       useMacAsName: node.useMacAsName,
       ports: node.ports,
+      system: systemOf(node.system),
     })),
     cables: view.cables,
     documentation: view.documentation,
@@ -73,7 +97,12 @@ function topologyOf(view: JavaFile) {
  *    each load) has the one the simulation uses, derived from its port id;
  *  - documentation: the items in the model's render order (rectangles below
  *    text), a missing text empty, a missing font Dialog 12, and at least the
- *    editor's smallest size (DOCUMENTATION_MINIMUM_SIZE).
+ *    editor's smallest size (DOCUMENTATION_MINIMUM_SIZE);
+ *  - switchSsid: a switch's SSID the file lacked (Java rolls one) is the one
+ *    the model derives from the node's id;
+ *  - modemRoles: the model keeps a pair of modems, not which one serves: the
+ *    first of a pair in node order serves, the others connect. Both ways
+ *    work within one project, where the client connects to localhost.
  */
 const DEPARTURES = {
   generatedMac(view: JavaFile, macs: (string | undefined)[][]): JavaFile {
@@ -87,6 +116,20 @@ const DEPARTURES = {
       })),
     };
   },
+  switchSsid(view: JavaFile, nodeIds: Id[]): JavaFile {
+    return mapSystems(view, (node, index) =>
+      node.class === 'Switch' && node.system.ssid === null ? { ...node.system, ssid: defaultSwitchConfiguration(nodeIds[index]!).ssid } : node.system,
+    );
+  },
+  modemRoles(view: JavaFile, pairs: (string | undefined)[]): JavaFile {
+    const seen = new Set<string | undefined>();
+    return mapSystems(view, (node, index) => {
+      if (node.class !== 'Modem') return node.system;
+      const serves = !seen.has(pairs[index]);
+      seen.add(pairs[index]);
+      return { ...node.system, modem: { ...(node.system.modem as object), mode: serves ? 1 : 2 } };
+    });
+  },
   documentation(view: JavaFile): JavaFile {
     const items = (view.documentation as Record<string, unknown>[]).map((item) => {
       const [x, y, width, height] = item.bounds as number[];
@@ -101,6 +144,10 @@ const DEPARTURES = {
   },
 };
 
+function mapSystems(view: JavaFile, system: (node: JavaNode, index: number) => Record<string, unknown>): JavaFile {
+  return { ...view, nodes: view.nodes.map((node, index) => ({ ...node, system: system(node, index) })) };
+}
+
 /** Documentation items in an order that does not depend on the list's. */
 function sortedDocumentation(items: unknown[]): unknown[] {
   return items.map((item) => JSON.stringify(item)).sort().map((text) => JSON.parse(text) as unknown);
@@ -111,7 +158,12 @@ function portIds(project: ReturnType<typeof importProject>): Id[][] {
   return project.graph.nodes.map((node) => node.ports.map((port) => port.id));
 }
 
-const departed = { generatedMac: new Set<string>(), documentation: new Set<string>() };
+const departed = {
+  generatedMac: new Set<string>(),
+  documentation: new Set<string>(),
+  switchSsid: new Set<string>(),
+  modemRoles: new Set<string>(),
+};
 
 describe('the editor model exported, as Java loads it', () => {
   for (const file of flsFiles(corpusRoot)) {
@@ -138,22 +190,54 @@ describe('the editor model exported, as Java loads it', () => {
         }),
       );
       const source = original[name]!;
-      const withMacs = DEPARTURES.generatedMac(source, macs);
-      const expected = DEPARTURES.documentation(withMacs);
-      if (JSON.stringify(withMacs) !== JSON.stringify(source)) departed.generatedMac.add(name);
-      if (JSON.stringify(expected.documentation) !== JSON.stringify(source.documentation)) departed.documentation.add(name);
+      const nodeIds = project.graph.nodes.map((node) => node.id);
+      const pairs = nodeIds.map((id) => project.remoteLinkConfigurations.get(id)?.pairIdentifier);
+      const steps: [keyof typeof departed, (view: JavaFile) => JavaFile][] = [
+        ['generatedMac', (view) => DEPARTURES.generatedMac(view, macs)],
+        ['switchSsid', (view) => DEPARTURES.switchSsid(view, nodeIds)],
+        ['modemRoles', (view) => DEPARTURES.modemRoles(view, pairs)],
+        ['documentation', (view) => DEPARTURES.documentation(view)],
+      ];
+      let expected = source;
+      for (const [departure, apply] of steps) {
+        const next = apply(expected);
+        if (departure === 'documentation') {
+          if (JSON.stringify(next.documentation) !== JSON.stringify(expected.documentation)) departed[departure].add(name);
+        } else if (JSON.stringify(next) !== JSON.stringify(expected)) {
+          departed[departure].add(name);
+        }
+        expected = next;
+      }
       expect(topologyOf({ ...java!, documentation: sortedDocumentation(java!.documentation) })).toEqual(topologyOf(expected));
     });
   }
 
   it('departs from Java where the model decides differently', () => {
-    expect(departed.generatedMac.size).toBeGreaterThan(0);
-    expect(departed.documentation.size).toBeGreaterThan(0);
+    for (const [departure, files] of Object.entries(departed)) expect(files.size, departure).toBeGreaterThan(0);
   });
 });
 
 // ── A model beyond the corpus, loaded by Java ──────────────────────────────
 
+/** A model without nodes, settings or documentation. */
+function emptyProject(): ProjectToExport {
+  return {
+    graph: { nodes: [], links: [] },
+    deviceConfigurations: new Map(),
+    interfaceConfigurations: new Map(),
+    hostWirelessConfigurations: new Map(),
+    switchConfigurations: new Map(),
+    manualRoutesByNodeId: new Map(),
+    ripEnabledByNodeId: new Map(),
+    firewallConfigurationsByNodeId: new Map(),
+    dhcpClientConfigurations: new Map(),
+    dhcpServerConfigurations: new Map(),
+    portForwardingRowsByNodeId: new Map(),
+    remoteLinkConfigurations: new Map(),
+    documentationItems: [],
+  };
+}
+
 const port = (id: string) => ({ id, label: id, isOccupied: false });
 
 /**
@@ -162,12 +246,17 @@ const port = (id: string) => ({ id, label: id, isOccupied: false });
  * interfaces and a gateway, a half-transparent bold text and a rectangle.
  */
 const SYNTHETIC: ProjectToExport = {
+  ...emptyProject(),
   graph: {
     nodes: [
       { id: 'pc', kind: 'pc', displayName: 'PC', hostLabelPolicy: 'ipAndMAC', position: { x: 10.6, y: 20.2 }, ports: [port('p0')] },
       { id: 'sw', kind: 'networkSwitch', displayName: 'SW', hostLabelPolicy: 'manual', position: { x: 100, y: 20 }, ports: ['s0', 's1', 's2', 's3', 's4'].map(port) },
       { id: 'nb', kind: 'notebook', displayName: 'NB', hostLabelPolicy: 'macAddress', position: { x: 100, y: 120 }, ports: [port('n0')] },
       { id: 'rt', kind: 'router', displayName: 'RT', hostLabelPolicy: 'manual', position: { x: 200, y: 20 }, ports: ['r0', 'r1', 'r2'].map(port) },
+      { id: 'gw', kind: 'gateway', displayName: 'GW', hostLabelPolicy: 'manual', position: { x: 300, y: 20 }, ports: ['g0', 'g1'].map(port) },
+      { id: 'm1', kind: 'remoteLink', displayName: 'M1', hostLabelPolicy: 'manual', position: { x: 400, y: 20 }, ports: [port('m1p')] },
+      { id: 'm2', kind: 'remoteLink', displayName: 'M2', hostLabelPolicy: 'manual', position: { x: 500, y: 20 }, ports: [port('m2p')] },
+      { id: 'm3', kind: 'remoteLink', displayName: 'M3', hostLabelPolicy: 'manual', position: { x: 600, y: 20 }, ports: [port('m3p')] },
     ],
     links: [
       { id: 'l1', sourceNodeId: 'pc', sourcePortId: 'p0', targetNodeId: 'sw', targetPortId: 's4' },
@@ -184,6 +273,56 @@ const SYNTHETIC: ProjectToExport = {
     ['rt/r0', { ipAddress: '10.1.0.1', subnetMask: '255.255.0.0' }],
     ['rt/r1', { ipAddress: '10.0.0.254', subnetMask: '255.255.255.0' }],
     ['rt/r2', { ipAddress: '10.2.0.1', subnetMask: '255.255.0.0' }],
+    ['gw/g0', { ipAddress: '42.0.0.7', subnetMask: '255.0.0.0' }],
+    ['gw/g1', { ipAddress: '192.168.1.1', subnetMask: '255.255.255.0' }],
+  ]),
+  switchConfigurations: new Map([['sw', { ssid: 'S-net', retentionTimeMilliseconds: 1234 }]]),
+  manualRoutesByNodeId: new Map([
+    ['pc', [{ destinationNetwork: '10.5.0.0', subnetMask: '255.255.0.0', gateway: '10.0.0.254', interfaceIPAddress: '10.0.0.1' }]],
+    ['rt', [{ destinationNetwork: '10.6.0.0', subnetMask: '255.255.0.0', gateway: '10.1.0.2', interfaceIPAddress: '10.1.0.1' }]],
+  ]),
+  ripEnabledByNodeId: new Map([['rt', true]]),
+  firewallConfigurationsByNodeId: new Map([
+    [
+      'rt',
+      firewallConfiguration({
+        isActive: true,
+        defaultPolicy: 'accept',
+        dropIcmp: true,
+        filterSynSegmentsOnly: false,
+        filterUdp: false,
+        rules: [
+          firewallRule({ sourceIPAddress: '10.0.0.0', sourceSubnetMask: '255.0.0.0', protocol: 'all', action: 'accept' }),
+          firewallRule({ destinationIPAddress: '10.2.0.5', destinationSubnetMask: '255.255.255.255', port: 80, protocol: 'tcp' }),
+          firewallRule({ port: 53, protocol: 'udp', action: 'accept' }),
+          firewallRule({ protocol: 'icmp' }),
+        ],
+      }),
+    ],
+  ]),
+  dhcpClientConfigurations: new Map([
+    ['pc', { isEnabled: true }],
+    ['gw', { isEnabled: true }],
+  ]),
+  dhcpServerConfigurations: new Map([
+    [
+      'gw',
+      dhcpServerConfiguration({
+        isActive: true,
+        lowerBoundIPAddress: '192.168.1.100',
+        upperBoundIPAddress: '192.168.1.199',
+        gatewayIPAddress: '192.168.1.1',
+        dnsServerIPAddress: '8.8.8.8',
+        useOwnSettings: true,
+        staticAssignments: [{ id: 'a1', macAddress: 'AA:BB:CC:DD:EE:77', ipAddress: '192.168.1.77' }],
+      }),
+    ],
+  ]),
+  portForwardingRowsByNodeId: new Map([['gw', [{ protocolValue: 'TCP', publicPortValue: '8080', lanIPAddress: '192.168.1.10', lanPortValue: '80' }]]]),
+  remoteLinkConfigurations: new Map([
+    ['m1', { pairIdentifier: 'java-modem-port-4242', latencyMilliseconds: 20, isEnabled: true }],
+    ['m2', { pairIdentifier: 'java-modem-port-4242', latencyMilliseconds: 20, isEnabled: true }],
+    ['m3', { pairIdentifier: 'our own pair', latencyMilliseconds: 20, isEnabled: true }],
   ]),
   hostWirelessConfigurations: new Map([['nb', { isEnabled: true, ssid: 'net' }]]),
   documentationItems: [
@@ -227,6 +366,15 @@ describe('a model beyond the corpus, as Java loads it', () => {
     );
     expect(warnings).toEqual([]);
     const card = (ip: string, mask: string, mac: string, gateway: string, dns: string, wireless = false) => ({ ip, mask, mac, gateway, dns, wireless });
+    const modem = (name: string, x: number, mode: number, port: number) => ({
+      class: 'Modem',
+      name,
+      position: [x, 20],
+      useIpAsName: undefined,
+      useMacAsName: undefined,
+      ports: [{}],
+      system: { modem: { mode, port, ipAdresse: 'localhost' } },
+    });
     expect(topologyOf(java!)).toEqual({
       success: true,
       nodes: [
@@ -237,8 +385,22 @@ describe('a model beyond the corpus, as Java loads it', () => {
           useIpAsName: true,
           useMacAsName: true,
           ports: [card('10.0.0.1', '255.255.255.0', stableGeneratedMacAddress('p0'), '10.0.0.254', '10.0.0.53')],
+          system: {
+            ssid: null,
+            manualRoutes: [['10.5.0.0', '255.255.0.0', '10.0.0.254', '10.0.0.1']],
+            dhcpClient: true,
+            dhcpServer: JAVA_DHCP_DEFAULTS,
+          },
+        },
+        {
+          class: 'Switch',
+          name: 'SW',
+          position: [100, 20],
+          useIpAsName: undefined,
+          useMacAsName: undefined,
+          ports: [{}, {}, {}, {}, {}],
+          system: { ssid: 'S-net', retentionTime: 1234 },
         },
-        { class: 'Switch', name: 'SW', position: [100, 20], useIpAsName: undefined, useMacAsName: undefined, ports: [{}, {}, {}, {}, {}] },
         {
           class: 'Notebook',
           name: 'NB',
@@ -246,6 +408,7 @@ describe('a model beyond the corpus, as Java loads it', () => {
           useIpAsName: false,
           useMacAsName: true,
           ports: [card('10.0.0.2', '255.255.255.0', stableGeneratedMacAddress('n0'), '', '', true)],
+          system: { ssid: 'net', manualRoutes: [], dhcpClient: false, dhcpServer: JAVA_DHCP_DEFAULTS },
         },
         {
           class: 'Vermittlungsrechner',
@@ -258,7 +421,56 @@ describe('a model beyond the corpus, as Java loads it', () => {
             card('10.0.0.254', '255.255.255.0', stableGeneratedMacAddress('r1'), '10.9.9.9', '10.0.0.53'),
             card('10.2.0.1', '255.255.0.0', stableGeneratedMacAddress('r2'), '10.9.9.9', '10.0.0.53'),
           ],
+          system: {
+            ripEnabled: true,
+            manualRoutes: [['10.6.0.0', '255.255.0.0', '10.1.0.2', '10.1.0.1']],
+            dhcpClient: false,
+            dhcpServer: JAVA_DHCP_DEFAULTS,
+            firewall: {
+              activated: true,
+              defaultPolicy: 1,
+              dropICMP: true,
+              filterSYNSegmentsOnly: false,
+              filterUdp: false,
+              rules: [
+                ['10.0.0.0', '255.0.0.0', '', '', -1, -1, 1],
+                ['', '', '10.2.0.5', '255.255.255.255', 80, 6, 0],
+                ['', '', '', '', 53, 17, 1],
+                ['', '', '', '', -1, 1, 0],
+              ],
+            },
+          },
         },
+        {
+          class: 'Gateway',
+          name: 'GW',
+          position: [300, 20],
+          useIpAsName: undefined,
+          useMacAsName: undefined,
+          ports: [
+            card('42.0.0.7', '255.0.0.0', stableGeneratedMacAddress('g0'), '', ''),
+            card('192.168.1.1', '255.255.255.0', stableGeneratedMacAddress('g1'), '', ''),
+          ],
+          system: {
+            manualRoutes: [],
+            dhcpClient: true,
+            dhcpServer: {
+              aktiv: true,
+              untergrenze: '192.168.1.100',
+              obergrenze: '192.168.1.199',
+              gatewayip: '192.168.1.1',
+              dnsserverip: '8.8.8.8',
+              ownSettings: true,
+              staticAssignedAddresses: ['AA:BB:CC:DD:EE:77 192.168.1.77'],
+            },
+            staticNAT: [['TCP', '8080', '192.168.1.10', '80']],
+            firewall: { activated: false, defaultPolicy: 0, dropICMP: false, filterSYNSegmentsOnly: true, filterUdp: true, rules: [] },
+          },
+        },
+        // A pair on Java's port: the first serves; a pair of our own: Java's default port.
+        modem('M1', 400, 1, 4242),
+        modem('M2', 500, 2, 4242),
+        modem('M3', 600, 1, 12345),
       ],
       cables: [
         { ends: [[0, 0], [1, 4]], wireless: false, panel: [0, 1] },
@@ -273,6 +485,17 @@ describe('a model beyond the corpus, as Java loads it', () => {
   });
 });
 
+/** The DHCP server as every IP stack's constructor leaves it. */
+const JAVA_DHCP_DEFAULTS = {
+  aktiv: false,
+  untergrenze: '0.0.0.0',
+  obergrenze: '0.0.0.0',
+  gatewayip: '0.0.0.0',
+  dnsserverip: '0.0.0.0',
+  ownSettings: false,
+  staticAssignedAddresses: [],
+};
+
 // ── Rules the corpus does not exercise ─────────────────────────────────────
 
 describe('exportProject rules', () => {
@@ -293,11 +516,9 @@ describe('exportProject rules', () => {
     targetPortId: target[1],
   });
   const project = (nodes: TopologyNode[], links: ReturnType<typeof link>[], wireless: [string, boolean][] = []): ProjectToExport => ({
+    ...emptyProject(),
     graph: { nodes, links },
-    deviceConfigurations: new Map(),
-    interfaceConfigurations: new Map(),
     hostWirelessConfigurations: new Map(wireless.map(([id, isEnabled]) => [id, { isEnabled, ssid: 'net' }])),
-    documentationItems: [],
   });
 
   it('leaves out a node of a kind Java does not have, and the links to it', () => {