diff --git a/test/modelgrid-config_test.ts b/test/modelgrid-config_test.ts
index 75eecca..c727137 100644
--- a/test/modelgrid-config_test.ts
+++ b/test/modelgrid-config_test.ts
@@ -1,6 +1,7 @@
 import { assertEquals } from 'jsr:@std/assert@^1.0.0';
 import { ConfigManager } from '../ts/config/config-manager.ts';
 import type { IModelGridConfig } from '../ts/interfaces/config.ts';
+import { logger } from '../ts/logger.ts';
 
 Deno.test('ConfigManager normalizes current config defaults', () => {
   const configManager = new ConfigManager();
@@ -46,3 +47,73 @@ Deno.test('ConfigManager normalizes current config defaults', () => {
   assertEquals(normalized.ui.port, 8081);
   assertEquals(normalized.ui.assetSource, 'bundle');
 });
+
+Deno.test('ConfigManager warns when config contains ignored keys', () => {
+  const configManager = new ConfigManager();
+  const warnings: string[] = [];
+  const originalWarn = logger.warn;
+  logger.warn = (message: string) => {
+    warnings.push(message);
+  };
+
+  try {
+    configManager.normalizeConfig({
+      version: '1.0.0',
+      api: {
+        port: 8080,
+        host: '127.0.0.1',
+        apiKeys: [],
+      },
+      docker: {
+        networkName: 'modelgrid',
+        runtime: 'docker',
+      },
+      gpus: {
+        autoDetect: true,
+        assignments: {},
+      },
+      containers: [
+        { id: 'legacy', type: 'ollama' } as never,
+      ],
+      models: {
+        registryUrl: 'https://example.com/catalog.json',
+        autoDeploy: true,
+        defaultEngine: 'vllm',
+        autoLoad: [],
+        greenlistUrl: 'https://legacy.example.com/catalog.json',
+        autoPull: true,
+        defaultContainer: 'legacy-container',
+      } as IModelGridConfig['models'] & {
+        greenlistUrl: string;
+        autoPull: boolean;
+        defaultContainer: string;
+      },
+      cluster: {
+        enabled: false,
+        nodeName: 'modelgrid-local',
+        role: 'standalone',
+        bindHost: '0.0.0.0',
+        gossipPort: 7946,
+        heartbeatIntervalMs: 5000,
+        seedNodes: [],
+      },
+      checkInterval: 30000,
+      legacySection: true,
+    } as Partial<IModelGridConfig> & {
+      legacySection: boolean;
+      models: IModelGridConfig['models'] & {
+        greenlistUrl: string;
+        autoPull: boolean;
+        defaultContainer: string;
+      };
+    });
+  } finally {
+    logger.warn = originalWarn;
+  }
+
+  assertEquals(warnings.includes('Ignoring unknown config key: legacySection'), true);
+  assertEquals(warnings.includes('Ignoring removed config key: models.greenlistUrl'), true);
+  assertEquals(warnings.includes('Ignoring removed config key: models.autoPull'), true);
+  assertEquals(warnings.includes('Ignoring removed config key: models.defaultContainer'), true);
+  assertEquals(warnings.includes('Ignoring unsupported container type: ollama'), true);
+});
diff --git a/ts/config/config-manager.ts b/ts/config/config-manager.ts
index 07facf2..a1c004f 100644
--- a/ts/config/config-manager.ts
+++ b/ts/config/config-manager.ts
@@ -1,6 +1,7 @@
 import * as fs from 'node:fs/promises';
 import { PATHS, VERSION } from '../constants.ts';
 import type { IModelGridConfig } from '../interfaces/config.ts';
+import { logger } from '../logger.ts';
 
 export class ConfigManager {
   public async loadConfig(): Promise<IModelGridConfig> {
@@ -21,6 +22,8 @@ export class ConfigManager {
   }
 
   public normalizeConfig(config: Partial<IModelGridConfig>): IModelGridConfig {
+    this.logIgnoredConfigKeys(config);
+
     const filteredContainers = (config.containers || []).filter(
       (container) => (container as { type?: string }).type !== 'ollama',
     );
@@ -72,4 +75,38 @@ export class ConfigManager {
       checkInterval: config.checkInterval || 30000,
     };
   }
+
+  private logIgnoredConfigKeys(config: Partial<IModelGridConfig>): void {
+    const unknownTopLevelKeys = Object.keys(config).filter((key) =>
+      !['version', 'api', 'ui', 'docker', 'gpus', 'containers', 'models', 'cluster', 'checkInterval']
+        .includes(key)
+    );
+
+    for (const key of unknownTopLevelKeys) {
+      logger.warn(`Ignoring unknown config key: ${key}`);
+    }
+
+    const legacyModelConfig = config.models as {
+      greenlistUrl?: string;
+      autoPull?: boolean;
+      defaultContainer?: string;
+    } | undefined;
+
+    if (legacyModelConfig?.greenlistUrl) {
+      logger.warn('Ignoring removed config key: models.greenlistUrl');
+    }
+    if (legacyModelConfig?.autoPull !== undefined) {
+      logger.warn('Ignoring removed config key: models.autoPull');
+    }
+    if (legacyModelConfig?.defaultContainer) {
+      logger.warn('Ignoring removed config key: models.defaultContainer');
+    }
+
+    for (const container of config.containers || []) {
+      const containerType = (container as { type?: string }).type;
+      if (containerType === 'ollama') {
+        logger.warn('Ignoring unsupported container type: ollama');
+      }
+    }
+  }
 }