A large company is deploying network connectivity to multiple ISP sites. What are two considerations for running IBGP on internal routers compared with redistributing a BGP table into an IGP? (Choose two.)

IT Questions Bank › Category: CCNP › A large company is deploying network connectivity to multiple ISP sites. What are two considerations for running IBGP on internal routers compared with redistributing a BGP table into an IGP? (Choose two.)

Question:

capability of custom routing decisions
scalability to handle a large number of routes
faster convergence after network changes
capability of load balancing over multiple routes
lower AD value

Explanation: When a company exchanges routes with multiple ISP sites, running IBGP on internal routers provides a better solution with the following features:

Scalability - The internet has 800,000+ IPv4 network prefixes and it continues to increase in size. IGPs cannot scale to that level of routes.
Custom routing - Link-state and distance vector routing protocols use one or more specific metrics as the primary method for route selection. IGP protocols always use this routing pattern for path selection. BGP uses multiple steps to identify the best path and to manipulate the path for a specific prefix based on the network layer reachability information (NLRI). The NLRI includes the network prefix, prefix length, and any BGP path attributes (PAs) for a specific route. If the route was considered from the prospective of an IGP, the chosen path could be considered longer or suboptimal than a path chosen by BGP.

Exam with this question: CCNP Enterprise: Advanced Routing (Version 8.0) – BGP Exam