企業は、最近、唯一の MPLS プロバイダーで障害が発生したため、WAN の可用性を強化する必要があります。提案されたソリューションは、迅速に導入でき、手頃な価格で、信頼性が高く、企業のプライマリ MPLS 接続のバックアップとして機能する必要があります。これらの要件を満たすソリューションはどれですか。
正解:A
Contracting an internet connection and deploying DMVPN is the most practical solution when the enterprise needs a fast, affordable, and reliable backup for a single MPLS provider. DMVPN can use broadband internet transport to build encrypted GRE/IPsec tunnels between sites, providing a backup WAN path without waiting for another private MPLS provider circuit. It supports dynamic routing and can be deployed incrementally, which makes it suitable after a recent outage when time and cost matter. BFD echo mode toward a provider PE can improve failure detection, but it does not create an alternate transport if the only MPLS provider has an outage. Adding a WAN router and a floating static route also fails unless another path exists. Contracting a second MPLS provider and deploying GETVPN may be robust, but it is slower and more expensive than the requested quick and affordable backup. Reference topics: DMVPN backup WAN, MPLS resiliency, internet VPN, IPsec, branch availability, rapid WAN deployment.