Exam 350-401 topic 1 question 17 discussion

I think correct answer is D

C is correct FIB has info about next hop and interface identifier so it has the routes for particular network destination

I will agree with C, because in answer D I do not like the second half. FIB is able to hold multiple next hops to a particular destination in order for routers to support equal cost load-balancing. If the D would be plural in the second half, it would be more true, but with only single route as hard statement invalidates D.

D is correct. RIB (Routing Information Base): It stores all routes learned by the router from various routing protocols and can include multiple routes to the same destination. FIB (Forwarding Information Base): It is derived from the RIB and contains only the best routes that are used for forwarding traffic.

A. The FIB maintains network topologies and routing tables. The RIB is a list of routes to particular network destinations. See answer C. Wrong answer. B. The FIB includes many routes to a single destination. The RIB is the best route to a single destination. See answer D. Wrong answer. C. The RIB is used to create network topologies and routing tables. The FIB is a list of routes to particular network destinations. Each protocol has its own network topology and routing table. Then, each protocol chooses the best route to a particular destination to be included in the global RIB. Which may contain many routes to a single subnet/host. The FIB, along with the adjacency table, is used to forward a packet to the correct next-hop, through a specific interface. Wrong answer. D. The RIB includes many routes to the same destination prefix. The FIB contains only the best route. The RIB contains the best route per each routing protocol running on a router. When CEF is enabled: - the FIB includes the best route to a specific destination, among those in the RIB; - the adjacency table is a one-to-one mapping between each router’s interface and the corresponding next hop, for each route in the FIB. Correct answer.

deffirent between RIB and FIB By contenent : The RIB typically includes all of the routes that have been learned by the router, including those that are not currently being used to forward packets. The FIB, on the other hand, only includes the routes that have been selected as the best path to each destination and are currently being used to forward packets. by Purpose: The RIB is used by the router to determine the best path to a destination, FIB is used by the router to actually forward packets to their destination. C and D seem bothe true but for D The RIB includes many routes to the same destination prefix (but it includes also the best route because the best routes are determeined by RIB). The FIB contains only the best route For C The RIB is used to create network topologies and routing tables(and to determeine the Best way). The FIB is a list of routes to particular network destinations. C is more accurate as a text from D

Guys, FIB is used by CEF to determine routes to several destinations, these destinations may contain several routes to the same destination because it's a full list of all possible routes. RIB is the (Routing Table) and it mirrors the FIB but it only pulls best Route to the Single Destination. You will never see several routes to the same destination on the Routing Table (RIB) unless you are doing load balancing with a Routing Protocol or Static Route. All it takes is go into Packet Tracer, create a topology with several destinations and compare the FIB with the RIB and you will see 100% of the time the RIB only pulls best route to a single destination. Correct answer is B. This one is was a tricky one and i can see how people could get confused.

https://theunprecedentedcult.in/articles/technology/cisco-express-forwarding-rib-fib/ "Each routing protocol maintains its own RIB or routing database. Only the best routes to a destination make it to the Global Routing Information Base or as we call it, the IP Routing table." https://www.cisco.com/c/en/us/td/docs/iosxr/ncs5500/routing/72x/b-routing-cg-ncs5500-72x/implementing-and-monitoring-rib.html "Each routing protocol selects its own set of best routes and installs those routes and their attributes in RIB. RIB stores these routes and selects the best ones from among all routing protocols. ...The acronym RIB is used both to refer to RIB processes and the collection of route data contained within RIB" https://www.cisco.com/c/en/us/support/docs/routers/12000-series-routers/47321-ciscoef.html "It (CEF) maintains a mirror image of the forwarding information contained in the IP routing table" =>There are several different RIBs, and the best routes from all RIB's are placed into the global rib, and then FIB is built based on this information.

The correct statement is: D. The RIB includes many routes to the same destination prefix. The FIB contains only the best route. Explanation: In computer networking, the RIB (Routing Information Base) and FIB (Forwarding Information Base) are two different data structures used for storing and forwarding network routing information. The RIB is a list of routes to a particular destination network prefix. It can contain multiple routes to the same destination prefix, each with different metrics (such as hop count, bandwidth, delay, etc.) assigned by different routing protocols or network administrators. On the other hand, the FIB is a list of routes that the router has chosen as the best paths to reach each destination prefix, based on the information stored in the RIB. The FIB is used by the router's forwarding engine to actually forward packets towards their destinations. Therefore, option D is correct, as it correctly describes the differences between the RIB and FIB in terms of the number of routes they store for each destination prefix. The other options are incorrect or incomplete in some way.

this is a rick question. with D, the FIB part is likely correct, but the RIB part is not necessarily correct for two reasons: A. if the RIB had multiple paths, there were be some instances of a single path, so the logic of the phrase is wrong, by suggesting that all all roues in the RIB are mult-path. B. with ecmp enables (and it can be diabled), that will actually install multiple routes in the RIB. lookup ECMP. this implies that the RIB often doesnt have multiple routes in it. In my simple mind, route protocol database (sh ip ospf database) feeds into the RIB, and RIB coudl get overwritten by lets say a same prefix EIGRP route (ad=90, rather than ad=110). this would install in the RIB. then the RIB would feed the FIB, which combines the adjacency table to the route. so C is likely the best answer in a very strict case. but its a tricky question.

Answer options mentions RIB not RIBs. Answer is C. Each routing protocol has its own RIB and each RIB contains only one route to destination. Routing protocols such as OSPF, EIGRP, and BGP each have their own Routing Information Base (RIB). The best routes to each destination network are selected to be installed in the global RIB, or the IP routing table from each routing protocol RIB. If more than one routing protocol is being executed on a router, the best routes from each RIB will be chosen by a parameter called administrative distance. Administrative distance is the feature that routers use to select the best path when there are two or more different routes to the same destination from two different routing protocols. Administrative distance defines the reliability of a routing protocol. Each routing protocol is prioritized in order of most to least reliable (believable) with the help of an administrative distance value. The FIB is derived from the IP routing table and is arranged for maximum lookup throughput.

Routing protocols such as OSPF, EIGRP, and BGP each have their own Routing Information Base (RIB). The best routes to each destination network are selected to be installed in the global RIB, or the IP routing table from each routing protocol RIB. If more than one routing protocol is being executed on a router, the best routes from each RIB will be chosen by a parameter called administrative distance. Administrative distance is the feature that routers use to select the best path when there are two or more different routes to the same destination from two different routing protocols. Administrative distance defines the reliability of a routing protocol. Each routing protocol is prioritized in order of most to least reliable (believable) with the help of an administrative distance value. The FIB is derived from the IP routing table and is arranged for maximum lookup throughput.

I agree with D. RIB is, in essence, a comprehensive database, housing a myriad of routing entries. Each routing entry includes vital data such as the network destination, associated subnet mask, next-hop IP address, and various attributes relevant to routing decisions. Conversely, the Forwarding Information Base, or FIB, has a more focused role within the router. Derived directly from the RIB, the FIB contains a subset of information critical to packet forwarding. FIB distills this comprehensive information into an efficient and streamlined set of next-hop entries. It represents the best path to reach each destination, ensuring optimal packet forwarding. https://www.youtube.com/watch?v=GaKmC7QK7E8

The correct answer is: D. The RIB includes many routes to the same destination prefix. The FIB contains only the best route. Explanation: RIB (Routing Information Base): It is a data structure that stores network routing information, including multiple routes to the same destination. Each route in the RIB has associated attributes such as administrative distance, metric, and more. The RIB is used by the routing protocol to maintain a comprehensive view of the network's routing information. FIB (Forwarding Information Base): It is a data structure that stores the best (selected) routes from the RIB. Unlike the RIB, the FIB only contains the best routes for each destination prefix. The FIB is used by the forwarding plane to make decisions about where to forward packets. In summary, the RIB contains a more comprehensive set of routes, including multiple routes to the same destination, while the FIB contains only the best route for each destination.

D is correct ---> RIB stores all learned routes to a destination. FIB stores only the best route to that same destination. A is wrong ---> RIB maintains only the routing table. B is wrong---> FIB contains only a single route to each destination, while RIB contains all routes learned to a single destination. C is wrong ---> Routing tables are created using RIB, but network topologies are managed/created using routing protocols.

it´s D RIB: is a data structure that contains all routes learned by a router, including multiple routes to the same destination prefix. These routes can come from various sources such as routing protocols, static routes, and directly connected networks. FIB: is a subset of the RIB and contains only the best route for each destination prefix as determined by the routing protocol's decision process. C is incorrect because RIB doesn't create network topologies, and FIB is not just a list of routes to particular network destinations, it contains the best routes selected from the RIB for each destination prefix.

Option D - RIB contains many routes to a destination. FIB has the association of best route (path) to the destination and the forwarding interface.