Ccna certification Practice Tests

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 195.  D.  Type 3 link-state advertisements (LSAs) contain summary information about the 

networks on the other side of the area boarder router (ABR). These LSA announcements 

are called summary link advertisements, or SLAs. ABRs sit between areas within OSPF. 

ABRs listen to Type 1 link-state advertisements but do not exchange. ABRs listen to Type 

2 link-state but do not exchange link state advertisement messages.

 196.  B.  The network IDs of 128.24.0.0/24, 128.24.1.0/24, 128.24.2.0/24, and 128.24.3.0/24 

can be summarized as 128.24.1.0/22. The wildcard-mask for /22 is 0.0.252.255. The 

commands 

network 128.24.0.0/22 area 0 and network 128.24.0.0/22 area 1 

are incorrect because they require a bitmask, not a CIDR notation. The commands 

128.24.0.0 0.0.254.255 area 0 and network 128.24.0.0 255.254.255 area 1 

are incorrect because the bitmask is incorrect. The command 

network 128.24.0.0 

0.0.255.255 is incorrect because it does not specify the area.

 197.  A.  The command 

show ip ospf database will show you a summary count of all the LSAs 

in the database. The command 

show ip ospf states is incorrect. The command show ip 

ospf neighbors is incorrect. The command show ip ospf topology is incorrect.

 198.  D.  Interface GigabitEthernet 0/0 is not participating because it is in a different network 

than what the wildcard mask is advertising. The wildcard mask of 0.0.0.63 is a /26 

network mask with the range of 197.234.3.0 to 197.234.3.63. The interface Gi0/0 is in 

the 197.234.3.64/26 network and therefore will not participate.

 199.  C.  The default hello interval on a LAN is 10 seconds. If a router is configured with a hello 

timer of 30, the hello/dead interval will not match. In order to form an adjacency, the 

hello/dead intervals must match. Static routes configured between the two routers will not 

affect their ability to form an adjacency. Configuring routers with multiple area IDs will 

not affect their ability to form adjacencies.

 200.  A.  Fast convergence of the Link State Database (LSDB) that feeds the routing tables is 

a direct result of a hierarchical OSPF design. The use of areas allows for routers within 

an area to converge and send summary link advertisements (LSAs) to other areas. OSPF 

design is much more complex than static routing or other dynamic routing protocols such 

as RIP. Bandwidth will not be increased with the implementation of OSPF. Security does 

not improve with OSPF.

 201.  B.  Designated routers (DRs) are only elected on broadcast (multi-access) networks such 

as a LAN. The router with the highest IP address will become the designated router. Since 

Router B has IP addresses of 192.168.10.2/30, 192.168.10.5/30, and 192.168.2.1/24, it 

will become the DR. Router C is on a nonbroadcast multi-access (NBMA), and therefore, 

it will not be elected to be a designated router (DR). Router D and Router E have IP 

addresses of 192.168.2.2/24 and 192.168.2.3/24, respectively, which are lower than 

Router B’s interfaces.

 202.  B.  Router B is called the area border router (ABR) since it sits between area 0 and area 1. 

An autonomous system boarder router (ASBR) is a router that sits between two or more 

autonomous systems (ASs), such as the Internet and an organization. A designated router 

(DR) is a router that is elected in a LAN to form neighborships with other routers. A 

backup designated router (BDR) is a router that is next in line if the DR fails.

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