OSPF Configuration Flashcards
7 cards from real ICND1 practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 OSPF Configuration flashcards as text
Which statement correctly describes OSPF route summarization at an Area Border Router (ABR)?
Answer: The 'area range' command is used on ABRs to summarize routes between areas
The 'area range' command on an ABR aggregates Type 3 LSAs sent between areas, reducing LSDB size.
A router's OSPF neighbor is stuck in the EXSTART state. What is the most likely cause?
Answer: MTU mismatch between the two routers
An MTU mismatch causes DBD packets to be dropped, stalling the adjacency in the ExStart/Exchange state.
Which command manually sets the OSPF cost on an interface to 50?
Answer: ip ospf cost 50
The interface-level command 'ip ospf cost 50' directly overrides the automatically calculated OSPF cost.
What does the 'network 10.0.0.0 0.255.255.255 area 0' command do under the OSPF process?
Answer: Enables OSPF on all interfaces with IPs matching the 10.x.x.x range and places them in area 0
The 'network' command with a wildcard mask enables OSPF on matching interfaces and assigns them to the specified area.
Which OSPF packet type is sent to request specific LSAs that a router does not have in its LSDB?
Answer: Link-State Request (LSR)
LSR packets are sent after comparing DBDs to request specific LSAs that are missing from the local LSDB.
What is the default OSPF process ID scope on a Cisco router?
Answer: The process ID is locally significant and does not need to match neighbors
The OSPF process ID is locally significant only; different routers can use different process IDs and still form adjacencies.
Which show command confirms that OSPF routes have been installed in the routing table and displays their costs?
Answer: show ip route ospf
'show ip route ospf' displays all OSPF-learned routes with their metric (cost) and next-hop information.