Customers look for the redundancy of lan and wan because of more uptime . In those scenarios , two routers deply at customer premises and two wan links from different PE are required. In this topology, I am assuming the customer is using the same service provider with redundant pops. Hot Standy Routing Protocol aka HSRP with single group is deployed for lan and static routing is being used between PE and CE. R5 is having the higher priority and working as active router and R4 is working as standby router.
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