CCNA 3 v7 Modules 1 - 2: OSPF Concepts and Configuration
An administrator is configuring single-area OSPF on a router. One of the networks that must be advertised is 64.102.0.0 255.255.255.128. What wildcard mask would the administrator use in the OSPF network statement?
0.0.0.127
An administrator is configuring single-area OSPF on a router. One of the networks that must be advertised is 64.100.0.0 255.255.255.0. What wildcard mask would the administrator use in the OSPF network statement?
0.0.0.255
An administrator is configuring single-area OSPF on a router. One of the networks that must be advertised is 128.107.0.0 255.255.255.192. What wildcard mask would the administrator use in the OSPF network statement?
0.0.063
An administrator is configuring single-area OSPF on a router. One of the networks that must be advertised is 192.168.223.0 255.255.254.0. What wildcard mask would the administrator use in the OSPF network statement?
0.0.1.255
An administrator is configuring single-area OSPF on a router. One of the networks that must be advertised is 198.19.0.0 255.255.252.0. What wildcard mask would the administrator use in the OSPF network statement?
0.0.3.255
By default, what is the OSPF cost for any link with a bandwidth of 100 Mb/s or greater?
1
What is the default router priority value for all Cisco OSPF routers?
1
single-area OSPF
All the routers are in the backbone area
What is the recommended Cisco best practice for configuring an OSPF-enabled router so that each router can be easily identified when troubleshooting routing issues?
Configure a value using the router-id command.
After modifying the router ID on an OSPF router, what is the preferred method to make the new router ID effective?
HQ# clear ip ospf process
Which three OSPF states are involved when two routers are forming an adjacency? (Choose three.)
Init Two-way Down
In an OSPFv2 configuration, what is the effect of entering the command network 192.168.1.1 0.0.0.0 area 0?
It tells the router which interface to turn on for the OSPF routing process.
Which OPSF packet contains the different types of link-state advertisements?
LSU
Which three statements describe features of the OSPF topology table? (Choose three.)
The table can be viewed via the show ip ospf database command. It is a link-state database that represents the network topology. When converged, all routers in an area have identical topology tables.
What is a benefit of multiarea OSPF routing?
Topology changes in one area do not cause SPF recalculations in other areas.
What is the format of the router ID on an OSPF-enabled router?
a 32-bit number formatted like an IPv4 address
link-state update packet
advertise new information
What will an OSPF router prefer to use first as a router ID?
any IP address that is configured using the router-id command
Which step in the link-state routing process is described by a router building a link-state database based on received LSAs?
building the topology table
Which step in the link-state routing process is described by a router inserting best paths into the routing table?
choosing the best route
database description packet
compare local topology to that sent by another router
Which type of OSPFv2 packet contains an abbreviated list of the LSDB of a sending router and is used by receiving routers to check against the local LSDB?
database description
To establish a neighbor adjacency two OSPF routers will exchange hello packets. Which two values in the hello packets must match on both routers? (Choose two.)
dead interval hello interval
hello packet
establish and maintain adjacencies
Which step in the link-state routing process is described by a router sending Hello packets out all of the OSPF-enabled interfaces?
establishing neighbor adjacencies
When an OSPF network is converged and no network topology change has been detected by a router, how often will LSU packets be sent to neighboring routers?
every 30 minutes
Which step does an OSPF-enabled router take immediately after establishing an adjacency with another router?
exchanges link-state advertisements
Which step in the link-state routing process is described by a router flooding link-state and cost information about each directly connected link?
exchanging link-state advertisements
Which step in the link-state routing process is described by a router running an algorithm to determine the best path to each destination?
executing the SPF algorithm
Exchange state
fifth state
Down state
first state
Exstart state
fourth state
What indicates to a link-state router that a neighbor is unreachable?
if the router no longer receives hello packets
Which OSPF data structure is identical on all OSPF routers that share the same area?
link-state database
What type of address is 64.101.198.197?
public
link-state request packet
query another router for additional information
An OSPF router has three directly connected networks; 172.16.0.0/16, 172.16.1.0/16, and 172.16.2.0/16. Which OSPF network command would advertise only the 172.16.1.0 network to neighbors?
router(config-router)# network 172.16.1.0 255.255.255.0 area 0
What does an OSPF area contain?
routers that have the same link-state information in their LSDBs
Init state
second state
full state
seventh state
Which command will a network engineer issue to verify the configured hello and dead timer intervals on a point-to-point WAN link between two routers that are running OSPFv2?
show ip ospf interface serial 0/0/0
What command would be used to determine if a routing protocol-initiated relationship had been made with an adjacent router?
show ip ospf neighbor
Which command is used to verify that OSPF is enabled and also provides a list of the networks that are being advertised by the network?
show ip protocols
Loading state
sixth state
A network technician issues the following commands when configuring a router: R1(config)# router ospf 11 R1(config-router)# network 10.10.10.0 0.0.0.255 area 0 What does the number 11 represent?
the OSPF process ID on R1
What is used to facilitate hierarchical routing in OSPF?
the use of multiple areas
two-way state
third state
Shortest path first
this is the algorithm used by OSPF
adjacency database
this is where the details of the neighboring routers can be found.
link-state database
this is where you can find the topology table.
What is a function of OSPF hello packets?
to discover neighbors and build adjacencies between them
What is the reason for a network engineer to alter the default reference bandwidth parameter when configuring OSPF?
to more accurately reflect the cost of links greater than 100 Mb/s
What are the two purposes of an OSPF router ID? (Choose two.)
to uniquely identify the router within the OSPF domain to facilitate router participation in the election of the designated router
In an OSPF network when are DR and BDR elections required?
when the routers are interconnected over a common Ethernet network
