Google Front End（GFE）に基づくロードバランサには、GFE プロキシからのトラフィックがバックエンド インスタンスに到達することを許可する上り（内向き）許可ファイアウォール ルールが必要です。ほとんどの場合、GFE プロキシはヘルスチェック プローブと同じ送信元 IP 範囲を使用するため、個別のファイアウォール ルールは必要ありません。次の表に例外を示します。
オープンソースの Envoy プロキシに基づくロードバランサには、プロキシ専用サブネットからのトラフィックがバックエンド インスタンスに到達できるように上り（内向き）ファイアウォール ルールを作成する必要があります。これらのロードバランサによって受信接続が終端され、ロードバランサからバックエンドへのトラフィックはプロキシ専用サブネットの IP アドレスから送信されます。
[[["わかりやすい","easyToUnderstand","thumb-up"],["問題の解決に役立った","solvedMyProblem","thumb-up"],["その他","otherUp","thumb-up"]],[["わかりにくい","hardToUnderstand","thumb-down"],["情報またはサンプルコードが不正確","incorrectInformationOrSampleCode","thumb-down"],["必要な情報 / サンプルがない","missingTheInformationSamplesINeed","thumb-down"],["翻訳に関する問題","translationIssue","thumb-down"],["その他","otherDown","thumb-down"]],["最終更新日 2025-09-04 UTC。"],[],[],null,["# Firewall rules\n\nGoogle Cloud load balancers typically require one or more firewall rules\nto ensure that traffic from clients reaches the backends.\n\n- Most load balancers are required to specify a health check for backend\n instances. For the health check probes to reach your backends, you must create\n an ingress allow [firewall rule](/firewall/docs/using-firewalls) that allows\n health check probes to reach your backend instances.\n\n- Load balancers based on Google Front Ends (GFEs) require an ingress allow\n firewall rule that permits traffic from the GFE proxy to reach the backend\n instances. In most cases, GFE proxies use the same source IP ranges as the\n health check probes and therefore don't require a separate firewall rule.\n Exceptions are noted in the following table.\n\n- Load balancers based on the open source Envoy proxy require an ingress allow\n firewall rule that permits traffic from the *proxy-only subnet* to reach the\n backend instances. These load balancers terminate incoming connections and\n traffic from the load balancer to the backends is then sent from IP addresses\n in the proxy-only subnet.\n\nThe following table summarizes the minimum required firewall rules for each\ntype of load balancer.\n\n^1^\nAllowing traffic from Google's health check probe ranges isn't required for hybrid\nNEGs. However, if you're using a combination of hybrid and zonal NEGs in\na single backend service, you need to allow traffic from the [Google\nhealth check probe ranges](/load-balancing/docs/health-check-concepts#ip-ranges) for the zonal NEGs.\n\n^2^\nFor regional internet NEGs, health checks are optional. Traffic from load\nbalancers using *regional* internet NEGs originates from the [proxy-only subnet](/load-balancing/docs/proxy-only-subnets) and is then\nNAT-translated (by using Cloud NAT) to either manually or automatically allocated\nNAT IP addresses. This traffic includes both health check probes and user\nrequests from the load balancer to the backends. For details, see [Regional NEGs:\nUse a Cloud NAT gateway](/load-balancing/docs/negs/internet-neg-concepts#nat-support)."]]
