Ccna certification Practice Tests

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 2.  D.  Switches create collision domains by isolating the possibility of a collision to the 

segment it is transmitting to or receiving frames from. This in turn raises effective 

bandwidth for the rest of the segments. A firewall is a network device that can protect 

a network from malicious traffic and/or restrict access. A hub is nothing more than a 

multiport repeater and does not create broadcast domains. A router is a network device 

that routes layer 3 packets.

 3.  D.  Since the email server needs access to the Internet to send and receive mail, it should 

be placed in the demilitarized zone (DMZ). This will also allow access to internal clients 

in the inside zone. The inside zone is the private, or internal, network. The outside zone 

contains access for the public Internet, also called the perimeter or external network. A 

DNS zone is a database that serves resource records for an FQDN and has nothing to do 

with firewalls.

 4.  C.  Generally, office buildings do not have direct runs to each switch closet from the other 

closets. Although a full mesh is desirable, sometimes only a partial mesh is achievable. 

Traditional Ethernet-based networks function in a star topology, starting with a switch 

and connecting each client as a point on the star. A full mesh topology is often found 

between the core and distribution layers of the Cisco three-tier design model. A hybrid 

topology is found in many networks today because one topology does not fit all needs 

throughout the network.

 5.  B.  The Network Control Protocol (NCP) works at layer 3 tagging the network protocols 

from end to end when PPP is used. This gives PPP the ability to offer multiprotocol 

transport. Multiprotocol Label Switching (MPLS) is a routing technique in which the 

labels on the packets are tagged and packet switched throughout the provider’s network. 

The Link Control Protocol (LCP) is responsible for connection setup, authentication, 

and header compression, among other things. PCP is not a protocol commonly used, and 

therefore, it is an invalid answer.

 6.  A.  The command 

encapsulation ppp configures the serial interface with the Point to 

Point Protocol (PPP). PPP is an encapsulation protocol. The command 

protocol ppp 

is incorrect. The command 

ppp enable is incorrect. The command ppp protocol is 

incorrect.

 7.  A.  DSL access multipliers, or DSLAMs, share the local loop with analog phone traffic to 

intercept communications from the DSL modem. DSLAMs provide the switching of data 

to the Internet. A DSL concentrator is normally installed at a housing complex or hotel 

and allows for individual DSL lines to be created. The 5ESS switching system is used for 

switching plain old telephone system (POTS) calls. A digital cross-connect system is used 

to connect circuits between the local loop and the provider.

 8.  C.  The CIR, or committed information rate, is the sustainable speed which the customer 

can communicate on the Ethernet virtual circuit. This CIR is directly tied to the price 

of the Monthly Recurring Charge (MRC), since the service provider must dedicate this 

bandwidth for the customer agreement. The IP addresses and routing protocols used are 

agreed upon by the connecting parties and are not part of the Metro Ethernet connection. 

The use of Quality of Service (QoS) is agreed upon by the connecting parties as well.

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