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18 Cards in this Set
- Front
- Back
Is OSPF a Link-state or a distance vector protocol?
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Link-state
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What does LSA stand for?
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Link State advertisement
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How often are LSA's sent out?
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Every 30 minutes and immediatly when a router changes its state.
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What does SPF mean?
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Shortest Path First
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what is an Area in relation to OSPF?
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An area is a grouping of contigous networks. Areas are logical subdivisions of the autonomous system.
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What is an Autonomous system?
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An autonomous system consists of a collection of networks under a common administration that share a common routing strategy. An autonomous system, sometimes called a domain, can be logically subdivided into multiple areas.
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What does ABR stand for? What do they do?
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Area Border Router.
They attach to multiple areas, maintain seperate link-state databases for each area to which they are connected, and route traffic destined for or arriving from other areas. |
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What does ASBR stand for
What do they do? |
Autonomous system boundary Router
They connect to an external routing domain, or autonomous system |
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What do routers running OSPF use to establish neighbor adjacencies?
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The Hello protocol
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What information is included in the Hello packet?
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Router ID
Hello and Dead intervals Neighbors Area ID Router Priority DR and BDR IP addresses Authentication password Stub Area flag |
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What is the formula to calculate OSPF cost?
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reference bandwidth/interface bandwidth (in b/s)
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Under which circumstance, i.e. network type, would an OSPF router establish a neighbor adjacency, even though the DR/BDR election process was not performed?
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Point-to-point
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On what kinds of networks does the OSPF protocol elect a backup designated router?
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Broadcast
Non-broadcast multi-access |
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What is the default reference bandwidth for OSPF?
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10^8(10 to the 8th power) which is 100,000,000 which is equivalent to 100MB/s
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How does an OSPF router determine it's ID if not manually configured?
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It chooses the highest IP address on an active interface at the moment OSPF starts up, as its router ID. This can be overwritten by configuring a loopback interface.
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how many equal-cost metric paths will OSPF load balance over by default? What is the max amount of paths it would support if configured?
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4 by default
16 when configured |
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How many types of authentication does OSPF support? What are they?
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Plaintext and MD5(Message Digest 5)
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What four fields of the Hello packet MUST match before an OSPF adjacency can occur?
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Area ID
Hello and dead intervals Authentication password Stub area flag |