BGP routes are compared to other possible paths to networks in the IP routing table and the best route is placed into the IP routing table based on which metric?

• A. Local Preference
• B. Administrative Distance
• C. Metric
• D. Administrative Weight

Answer: (B)

Administrative Distance is the value that determines which routing source is trusted when multiple routes to the same destination exist from different protocols. It’s not about the quality of a particular path; it’s about how trustworthy the source of the route is. When a router has candidate routes from different sources (for example, BGP, static, or IGP), it compares their Administrative Distance values and installs the route with the lowest distance into the IP routing table.

Within BGP itself, there’s a separate path-selection process that looks at BGP attributes like Local Preference, AS-Path length, Origin, MED, and others to choose the best path among BGP routes. Those attributes influence which BGP path is considered the best, but the ultimate installation into the routing table across all sources is governed by Administrative Distance. Local Preference and Administrative Weight are BGP-specific factors affecting internal choice, not the cross-protocol installation metric, and a general numeric Metric isn’t used by BGP in the same way as for IGPs.