Ccna certification Practice Tests

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Appendix 

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  Answers to Practice Test Questions

 63.  B.  When a router’s interface is used to allow routing, the method is called router on a 

stick, or ROAS. Interface routing is used when an IP address is assigned to an interface 

and routing is enabled between the interfaces. Switched Virtual Interface (SVI) routing 

allows for the layer 3 router inside a switch to provide necessary routing between VLANs. 

There is no such thing as bridge routing; bridges are limited interface switches, and 

routing is a layer 3 function.

 64.  B.  Bandwidth is often a consideration because everything you send to the router must 

come back on the same port for routing to work. Routing between two VLANs on a 1 

Gb/s interface will allow for the bandwidth of 1 Gb/s up and 1 Gb/s down. When a third 

VLAN is introduced, they must all share the 1 Gb/s. Routers can handle large amounts 

of traffic, but the same interface used to receive is also used to send the traffic, thereby 

reducing the bandwidth by half. Security can be implemented with ROAS with the use of 

ACLs. Broadcast traffic is not increased by using a single router interface to route several 

VLANs.

 65.  C.  When you perform inter-VLAN routing on a layer 3 switch, it is called SVI VLAN 

routing. Interface routing is used when an IP address is assigned to an interface and 

routing is enabled between the interfaces. ROAS is used when a router only has one 

interface and you need to route multiple VLANs. There is no such thing as bridge routing; 

bridges are limited interface switches, and routing is a layer 3 function.

 66.  A.  Dynamic routing does not require any administrator intervention when routes go 

down. This is because dynamic routes send route notifications and recalculate the routing 

tables of all participating routers. Directly connected routes will require administrator 

intervention if the admin is relying upon the connected route as the route source and an 

interface goes down. Default routing requires administrator intervention if the default 

route goes down; the admin will need to pick a new default route and configure it. 

Static routing always requires an amount of administrator intervention for setup and 

maintenance of the routes since they are all done manually.

 67.  C.  Static routing requires increased time for configuration as networks grow in 

complexity. You will need to update routers that you add with all of the existing routes in 

the network. You will also need to update all of the existing routers with the new routes 

you add with the new router. RIP is a dynamic routing protocol and therefore requires 

less time as a network grows. OSPF is a dynamic routing protocol and therefore requires 

less time as a network grows. Default routing is used on stub networks and requires no 

additional time if the network remains a stub network.

 68.  D.  Default routing requires the least amount of RAM consumption because one routing 

statement is required for all of the upstream networks. This type of routing technique 

is best used on stub network routers. RIP routing requires an amount of RAM to hold 

its learned routes. OSPF requires a substantial amount of RAM because it holds learned 

routes and calculates the shortest path to remote networks. Static routing requires RAM 

for each route configured manually compared to default routing, which only requires one 

static entry.

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Chapter 3: IP Connectivity (Domain 3)