Which Routing Protocol Uses Attributes to Select the Best Path?
Which of the following routing protocols uses attributes to select the best path?
Community Votes
82% of anonymous learners picked answer B. Votes are pick records left by other test-takers — they are not the verified answer.
Community Insight
The question tests knowledge of which routing protocol uniquely relies on attributes rather than a simple metric, and the trap is confusing OSPF's cost or EIGRP's composite metric with BGP's path attributes.
The correct answer is BGP because BGP uses path attributes such as AS_PATH, NEXT_HOP, and LOCAL_PREF to select the best path. Community consensus strongly supports BGP, with 82 votes versus 18 for OSPF.
The most common wrong answer is OSPF, because exam takers may associate 'best path' with OSPF's SPF algorithm; however, OSPF uses cost, not attributes, while BGP's decision process is explicitly attribute-based.
Community Discussion (6 comments)
Comments & Corrections
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Expert Analysis
Why the Answer Is Correct
BGP is a path-vector routing protocol that selects the best route based on a set of path attributes, including AS_PATH, LOCAL_PREF, MED, and NEXT_HOP. This is a defining characteristic of BGP and is explained in RFC 4271. Comments [2] and [4] correctly point out that BGP's definition and operation are built around attributes for path selection.
The exam question specifically asks which protocol 'uses attributes,' and BGP is the only option that does so in its route selection process. EIGRP uses metric components, OSPF uses cost, and RIP uses hop count—none of them use attributes.
Why the Other Options Are Wrong
A. EIGRP is a hybrid protocol that uses a composite metric (bandwidth, delay, load, reliability, MTU) to calculate the best path, not attributes. C. OSPF uses link-state advertisements and Dijkstra's algorithm to compute shortest path based on cumulative cost, not attributes. D. RIP uses hop count as a simple metric and has no attribute-based path selection.
Thus, while EIGRP, OSPF, and RIP all have their own path-selection mechanisms, none are attribute-based in the sense defined by BGP. The phrase 'uses attributes' is a direct clue to BGP.
Community Comment Notes
The most useful comments correctly identify BGP: [2] notes BGP's definition mentions attributes, and [4] lists example attributes. Comment [3] incorrectly picks OSPF and says 'don't think too hard,' but this oversimplifies the question—OSPF does not use attributes. Comment [1] expresses frustration but does not provide reasoning, while comments [4] and [5] give solid support for BGP.
The community vote (82 for BGP) aligns with the correct answer. Learner should trust the definitional clue rather than overcomplicating the issue.
Official Reference
Exam Strategy
When a question mentions 'attributes,' immediately think BGP—BGP path attributes are unique among routing protocols. Memorize that OSPF uses cost, RIP uses hop count, EIGRP uses a composite metric, and BGP uses attributes to quickly eliminate wrong options.