Term
| Name two link state routing protocols used on IP networks. |
|
Definition
-Open Shortest Path First(OSPF)
-Intermediate System-to-Intermediate System (IS-IS) |
|
|
Term
| What routing algorithm is used by link state routing protocols? |
|
Definition
(SPF) algorithm
(Dijkstra's) |
|
|
Term
| What routing metric does OSPF use? |
|
Definition
|
|
Term
| Is the shortest path always the path with the smallest number of hops? |
|
Definition
|
|
Term
| How does a router running a link state routing protocol become aware of neighbors that are also running the same routing protcol? |
|
Definition
| By exchanging Hello packets with other link-state routers on directly connected networks. |
|
|
Term
| What is a link state packet? |
|
Definition
| Broadcast packet used by link-state protocols that contains information about neighbors and path costs. LSPs are used by the receiving router to maintain their routing tables. Also the state of the directly connected networks. |
|
|
Term
| What does a router do when it receives a link state packet from neighbor? |
|
Definition
| The router stores a copy of each LSP received from its neighbors in a local database. |
|
|
Term
| What does each router do after link state packets have all been exchanged? |
|
Definition
| Each router uses the database to construct a complete map of the topology and computes the best path to each destination network. |
|
|
Term
| Which routes does a router put in its routing table first? |
|
Definition
| Directly connected networks |
|
|
Term
|
Definition
| A link is an interface on a router |
|
|
Term
| What must be true before a link is included in the link state packet? |
|
Definition
| The link must be in the up state before the link-state routing protocol can learn a bout a link. The interface must also be included i nthe netwrok statements. |
|
|
Term
| What information about a link is included in the link state packet? |
|
Definition
| Contains the state of each directly connected network. |
|
|
Term
| How does the Cisco implementation of OSPF work? |
|
Definition
| OSPF specifies the cost of the link, the OSPF routingt mectric, as bandwidth of the outgoing interface. |
|
|
Term
| What is a "neighbor" for a link state routing protocol? |
|
Definition
| A neighbor is any other router that is enabled with the same link-state routing protocol. |
|
|
Term
| How are Hello messages used? |
|
Definition
| Router with link-state protocols use a Hello protocol to discover any neighbors on its links. |
|
|
Term
| How can a router tell if it receives a link state packet that it has already received earlier, so that there is no new information? |
|
Definition
| The use of sequence numbers and aging information in the LSP to help manage the flooding process. |
|
|
Term
| Do OSPF routers tell each other about best paths? |
|
Definition
|
|
Term
| What happens after a router has calculated the best route route to each network? |
|
Definition
| The routes are place in the routing table. |
|
|
Term
| When do link state routers send out LSPs? |
|
Definition
-During the initial startup of the router or of the routing protocol process on that router.
-Whenever there is a change in tthe topology including a link going down or coming up, or a neighbor adjacency being established or broken. |
|
|
Term
| How do link state routers manage to converge more quickly than routers running traditional distance vector routing protocols? |
|
Definition
| Link-state routing protocols calculate the SPF algorithm after flooding is complete. |
|
|
Term
| Why are OSPF and IS-IS suitable for very large groups of networks? |
|
Definition
-Builds a Topological map
-Fast Convergence
-Event driven updates
-Hierarchical design |
|
|
Term
| How can the heirarchical design help to cut down on processing time and the use of bandwidth? |
|
Definition
| The concept of areas or multiple areas create a hierarchical design to networks, allowing for better route aggregation and the isolation of routing issues within a area. |
|
|
Term
| When can the use of a link state routing protocol make great demands on bandwidth? |
|
Definition
| Flooding of link-state packets. |
|
|
Term
| Why do link state routing protocols require the use of relatively modern routers? |
|
Definition
| They require more memory and processing requirements. |
|
|
Term
| Which organizations designed OSPF and IS-IS? |
|
Definition
|
|
