Lack of memory or processor power on edge routers

• A. Low bandwidth on links
• B. Too many BGP neighbors
• C. BGP version mismatch
• D. Lack of memory or processor power on edge routers

Answer: (D)

Edge routers must manage a large amount of BGP state and policies in real time. Their memory holds all the routing information (the routing table, Adj-RIBs, and policy data), while the CPU handles the processing of updates, decisions, and any security checks like route validation or filtering. When memory is scarce or CPU cycles are overcommitted, the router can’t keep up with incoming updates, can drop sessions, or fail to install or validate routes promptly. This directly undermines stable BGP operation and security controls, making lack of memory or processing power on edge devices the root factor described.

The other issues describe different problems: low link bandwidth affects throughput, not the router’s ability to process BGP state; too many BGP neighbors can strain resources but is still a symptom of resource pressure rather than the root cause itself; a BGP version mismatch is a protocol compatibility problem, not a resource limitation.