Flashcards
Single-Area OSPF 1
Cards in this deck (101)
- 1It is a link-state routing protocol that was developed as a replacement for the distance vector routing protocol, RIP.Open Shortest Path First (OSPF)
- 2It is RIP's metric for determining the best route quickly.hop count
- 3T or F: Using hop count does not scale well in larger networks with multiple paths of varying speeds.TRUE
- 4T or F: An advantage of OSPF is having faster convergence and scales to much larger network implementations.TRUE
- 5OSPF is a _____ routing protocol that uses the concept of areas for ______.classless
scalability - 6What are the characteristics of OSPF?Classless
Efficient
Fast Convergence
Scalable
Secure - 7OSPF v3 for IPv6 currently published in _____.RFC 5340
- 8Supports VLSM and CIDR.Classless
- 9Routing changes trigger routing updates. It uses the SPF algorithm to choose the best path.Efficient
- 10T or F: OSPF has periodic updates.FALSE
- 11It is the algorithm used by OSPF to choose its best path.Djistra's SPF Algorithm
- 12It quickly propagates network changes.Fast Convergence
- 13It works well in small and large network sizes. Routers can be grouped into areas to support a hierarchical system.Scalable
- 14Routers can be grouped into _____ to support a _____.Areas
Hierarchical System - 15It supports Message Digest 5 (MD5) authentication. When enabled, OSPF routers only accept encrypted routing updates from peers with the same pre-shared password.Secure
- 16Authentication supported by OSPF.Message Digest 5 (MD 5)
- 17T or F: With Message Digest 5, routers can also accept routing updates that are not encrypted.FALSE
- 18What is the administrative distance for OSPF?110
- 19What are the components of OSPF?Data Structures
Routing Protocol Messages
Algorithm - 20OSPF's data structures consists of ____, ____, and ____.Adjacency database
Link-state database (LSDB)
Forwarding database - 21Creates the neighbor table.Adjacency database
- 22Creates the topology table.Link-state database (LDSB)
- 23Creates the routing table.Forwarding database
- 24These are [the Routing Protocol Messages] used to discover neighboring routers and also to exchange routing information to maintain accurate information about the network.Hello packet
Database description packet
Link-state request packet
Link-state update packet
Link-state acknowledgement packet - 25The SPF algorithm is based on the _____ to reach a destination.Cost
- 26The SPF algorithm creates an ____.SPF tree
- 27OSPF places the best routes into the ___, which is used to make the ____.Forwarding database
Routing table - 28It is a list of all neighbor routers to which a router has established bidirectional communication.Adjacency database
Neighbor Table - 29T or F: The Neighbor Table is unique for each router.TRUE
- 30Command to view the neighbor table.show ip ospf neighbor
- 31Lists information about all other routers in the network.Topology Table
- 32It represents the network topology.Link-state Database (LDSB)
- 33T or F: All routers within an area have different Link-state Database (LDSB).FALSE
- 34Command to view the topology table.show ip ospf database
- 35List of routes generated when an algorithm is run on the link-state database.Routing table
- 36T or F: Each router's routing table is unique.TRUE
- 37Command to view the routing table.show ip route
- 38Area 0 is called the ____.Backbone area
- 39Interconnecting routers are called ____.Area Border Routers (ABRs)
- 40T or F: Single-Area OSPF is useful in smaller networks with few routers.TRUE
- 41OSPF messages are transmitted over a/an ____.Ethernet link
- 42OSPF messages contain the following:Data Link Frame Header
IP Packet Header
OSPF Packet Header
OSPF Packet Type - 43OSPF uses ____ to establish and maintain neighbor adjacencies and exchange routing updates.Link-state Packets (LSPs)
- 44Used to establish and maintain adjacency with other OSPF routers.Hello Packet
- 45Contains the abbreviated list of the sending router's LDSB.Database Description (DBD) packet
- 46Used by the receiving routers to request more information about an entry in the DBD.Link-State Request (LSR) packet
- 47Used to reply to LSRs and to announce new information.Link-State Update (LSU) packet
- 48This is sent to confirm receipt of the LSU.Link-State Acknowledgment (LSAck) packet
- 49T or F: the LSAck data field is empty.TRUE.
- 50Used to discover OSPF neighbors and establish neighbor adjacencies.Hello Packet
- 51Hello packets elect the ____ and ____ on ____ networks like Ethernet and Frame Relay.Designated Router
Backup Designated Router
Multiaccess - 52T or F: Point-to-point links require DR or BDR.FALSE
- 53It is a 32-bit value expressed in dotted decimal notation (an IPv4 address) used to uniquely identifying the originating router.Router ID
- 54Subnet mask associated with the sending interface.Network Mask
- 55Area from which the packet originated.Area ID
- 56Specifies the frequency, in seconds, at which a router sends Hello packets.Hello Intval
- 57The default Hello interval on multiaccess and point-to-point networks is ____.10 seconds
- 58It is used in a DR/ BDR election.Router Priority
- 59What is the default priority for all OSPF routers?1
- 60T or F: The lower the value, the more likely the router becomes the DR on the link.FALSE
- 61It is the time in seconds that a router awaits to hear from a neighbor before declaring the neighboring router out of service.Dead Interval
- 62What is the default Dead Interval?Four times the Hello Interval
- 63What is the default Hello interval on nonbroadcast multiaccess [NBMA] networks; Frame Relay.30 seconds
- 64T or F: If the Dead interval expires before the routers receive a Hello packet, OSPF removes that neighbor from its LSDB.TRUE
- 65T or F: The router floods the LSDB with information about the down neighbor out all OSPF-enabled interfaces.TRUE
- 66What is the default Dead interval for multiaccess and point-to-point networks?40 seconds
- 67What is the default Dead interval for NBMA networks?120 seconds
- 68State where no Hello packets are received. Router sends Hello packets.Down State
- 69State where Hello packets are received from the neighbor.Init State
- 70State where electing a DR and BDR happen on Ethernet links.Two-Way State
- 71State where negotiation of master/ slave relationship and dbd packet sequence number happen.ExStart State
- 72State where routers exchange DBD packets.Exchange State
- 73State where LSRs and LSUs are used to gain additional router information. Routers are processed using the SPF algorithm.Loading State
- 74The ____ initiates the DBD packet exchange.master
- 75State where routers have converged.Full State
- 76T or F: More routers = more adjacenciesTRUE
- 77OSPFv2 is enabled using which commandin the global configuration mode?router ospf [process-id]
- 78The process-id value is ranged between?1 and 65,535
- 79Recommended method (command) to assign a router ID.router-id rid
- 80T or F: If the router ID is not explicitly configured, the router chooses the highest IPv4 address of any of configured loopback interfaces.TRUE
- 81T or F: If no loopback interfaces are configured, then the router chooses the highest inactive IPv4 address of any of its physical interfaces.FALSE
- 82A router ID can also be assigned using a _____.Loopback interface
- 83T or F: A 32-bit host route gets advertised as a route to other OSPF routers.FALSE
- 84The basic command syntax for enabling OSPF on interfaces is?network network-address wildcard-mask area area-id
- 85OSPF metric is ___.Cost
- 86T or F: Higher bandwidth = Lower costTRUE
- 87T or F: The cost of an interface is inversely proportional to the bandwidth of the interface.TRUE
- 88What is the default reference bandwidth?100,000,000
- 89OSPF cost formula is:Cost = reference bandwidth / interface bandwidth
- 90T or F: When adjusting the reference bandwidth, the command must be configured on every router in the OSPF domain.TRUE
- 91T or F: The bandwidth must be adjusted at each end of the serial links.TRUE
- 92This command is a quick way to verify vital OSPF configuration information.show ip protocols
- 93This command is used to verify OSPF Process Information.show ip ospf
- 94It is the OSPFv2 equivalent for exchanging IPv6 prefixes.OSPFv3
- 95What OSPFv3 feature supports both IPv4 and IPv6?OSPFv3 Address Families
- 96T or F: IPv6 and IPv4 routing protocols are basically the same and run dependently with each other.FALSE
- 97T or F: OSPFv2 and OSPFv3 each have separate adjacency tables, OSPF topology tables, and IP routing tables.TRUE
- 98Source/ Destination address for OSPFv3.IPv6 link-local address
- 99Authentication used for OSPFv3.IPv6 authentication
- 100T or F: IPv6 unicast forwarding is enabled by default.FALSE
- 101____ are automatically created when an IPv6 global unicast address is assigned to the interface.Link-local Address
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- Flashcards on Single-Area OSPF 1, created by Thea Usita on 16/11/2017.
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- Thea Usita
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