A spine-leaf (Clos) architecture provides the best combination of features for this scenario. It offers predictable low latency, non-blocking bandwidth between any endpoints, fast convergence through equal-cost multipathing, and excellent scalability. While a traditional three-tier design with EIGRP is common, the spine-leaf architecture better meets the strict performance and scalability requirements of a modern financial services network.

MPLS provides a private, managed network with QoS guarantees ideal for latency-sensitive traffic like VoIP and video as the primary link. Broadband Internet with DMVPN serves as a cost-effective, flexible backup that provides secure, dynamic connectivity if the MPLS link fails. This combination balances performance, reliability, and cost-effectiveness for regional offices.

In Cisco SD-Access, Control Plane nodes (running LISP) are deployed in an anycast redundancy group. This allows multiple nodes to share the same anycast address. Edge nodes are configured to communicate with this anycast address, providing automatic load balancing and seamless failover if one Control Plane node becomes unavailable, without requiring a stateful protocol like HSRP.

For a high-availability environment like a hospital, deploying multiple WLCs in a mobility group with AP load balancing (also called N+N or active/active) is recommended. APs are primed to multiple controllers, providing immediate failover without a discovery process. This model offers better resource utilization and faster failover than the N+1 model, where backup controllers are idle until a failure occurs.

PIM Source-Specific Multicast (SSM) is the best choice for a one-to-many streaming application over DMVPN. It simplifies design by eliminating the need for a Rendezvous Point (RP), which can be complex to manage in a tunneled network. Receivers join directly to the specific source address, providing inherent security against unwanted sources and optimizing the forwarding path.

An Ethernet over MPLS (EoMPLS) pseudowire is the preferred method. It allows the service provider to transparently extend a Layer 2 connection across their MPLS network. This offloads the complexity and control to the provider, is typically very stable, and isolates the customer’s Layer 2 traffic from their own routed IP VPN, enhancing security and stability compared to a customer-managed overlay like GRE.

To influence inbound traffic from the internet (i.e., which ISP link incoming traffic uses), the primary technique is BGP path manipulation as seen by the upstream ISPs. Prepending the company’s AS number multiple times in the AS_PATH attribute when advertising routes to a less-preferred ISP makes the path look longer, causing most external peers to prefer the path via the other ISP. LOCAL_PREF and WEIGHT influence outbound traffic, and MED is used between neighboring ASs with a special relationship.

vManage is the network management system (NMS) in the Cisco SD-WAN architecture. It provides a single pane of glass for centralized configuration (policies, templates), operational management, monitoring, and troubleshooting. The vSmart controllers handle routing policy and overlay intelligence, vBond handles initial onboarding, and vEdge/ cEdge routers are the forwarding devices at the sites.

The ‘area X range ‘ command is configured on the ABR, under the OSPF process, and specifically within the configuration of the non-backbone area (e.g., area 1) that contains the more specific routes. This tells the ABR to summarize those specific routes from area 1 before advertising them into other areas, like the backbone area 0.

A spine-leaf (Clos) architecture provides the best combination of features for this scenario. It offers predictable low latency, non-blocking bandwidth between any endpoints, fast convergence through equal-cost multipathing, and excellent scalability. While a traditional three-tier design with EIGRP is common, the spine-leaf architecture better meets the strict performance and scalability requirements of a modern financial services network.0