Chapter 5 final Flashcards
Which of the following statements correctly identify the differences between routing and forwarding. Select one or more statements
- Forwarding refers to moving packets from a router’s input to appropriate router output, and is implemented in the data plane.
- Routing refers to determining the route taken by packets from source to destination, and is implemented in the control plane.
Define Per-router control plane:
Individual routing algorithm components - with a component operating in each and every router - interact with each other in the control plane. The individual routing algorithm component executing in a given router computes the local fowarding table fir that router.
Software-defined networking (SDN)
A (typically) remote controller gathers information from routers, and then computes and installs the forwarding tables in routers.
What is the definition of a “good” path for a routing protocol? Chose the best single answer.
Routing algorithms typically work with abstract link weights that could represent any of, or combinations of, all of the other answers.
Consider Dijkstra’s link-state routing algorithm that is computing a least-cost path from node a to other nodes b, c, d, e, f. Which of the following statements is true.
- In the initialization step, the initial cost from a to each of these destinations is initialized to either the cost of a link directly connecting a to a direct neighbor, or infinity otherwise.
- Suppose nodes b, c, and d are in the set N’. These nodes will remain in N’ for the rest of the algorithm, since the least-cost paths from a to b, c, and d are known.
- The values computed in the vector D(v), the currently known least cost of a path from a to any node v, will never increase following an iteration.
Match the name of a general approach to routing with characteristics of that approach.
- Centralized, global routing => All routers have…
- Decentralized routing => an iterative process of computation…
- Static routing => routes change slowly over time
- Dynamic routing => routing changes quickly over time
Match the terms “interdomain routing” and intradomain routing” with their definitions. Recall that in Internet parlance, an “AS” refers to “Autonomous System” - a network under the control of a single organization.
- Interdomain routing => routing among different ASes (networks)
- Intradomain routing => routing among routers with same AS network
Check the one or more of the following statements about the OSPF protocol that are true.
- OSPF implements hierarchical routing
- OSPF is an intra-domain routing protocol.
- OSFP uses a Dijkstra-like algorithm to implement least cost path routing.
Consider the OSPF routing protocol. Which of the following characteristics are associated with OSPF (as opposed to BGP)?
- Is an intra-domain routing protocol.
- Finds a least cost path from source to destination.
- Floods link state control information.
Among the following protocols, terminology or considerations, indicate those that are associated with “routing within a single network (typically owned and operated by one organization).”
- OSPF
- Intra-AS routing
- Intra-domain routing
- Driven more by performance than by routing policy
Which of the functions below belong in the controller layer labeled “Interface, abstractions for network control apps”? Check all below that apply.
Intent, network graph
Which of the functions below belong in the controller layer labeled “Network-wide distributed, robust state management”? Check all below that apply.
Statistics, host information, flow tables, link-state information, switch information
Which of the functions below belong in the controller layer labeled “Communication to/from controlled device”?
openflow protocol
