Ccna certification Practice Tests

353

 85.  D.  When the queue depth is above the minimum threshold, a percentage of TCP packets 

are dropped. This allows the TCP window to shrink and allows a normal slowdown of 

TCP transmissions. This is done in hopes that the queue will fall under the minimum 

threshold and return to normal. Congestion avoidance tools drop all packets when the 

queue depth is full, but this is a cause of total congestion and not prevention of tail drop. 

When the queue depth is empty, nothing is dropped. When the queue depth is below the 

minimum threshold, nothing is dropped since this is optimal.

 86.  B.  AF41 marked traffic has a better position in the queue than traffic marked AF31. 

During high congestion times, traffic with lower positions in the queues (AF3x, AF2x, 

AF1x) would have more chances of being dropped than AF41. AF31 marked traffic is 

placed in a lower queue than traffic marked with AF41. AF31 and AF41 markings of 

traffic are not the same. During high congestion, traffic in the AF31 queue will be dropped 

before the AF 41 queue.

 87.  B.  The hostname and domain name are required before you attempt to generate the 

encryption keys for SSH. Although setting the time and date is good practice, it is not 

required for the generation of SSH encryption keys. Setting the key strength is not 

required for the generation of SSH encryption keys. Setting the key repository is not 

required for the generation of SSH encryption keys.

 88.  A.  The command 

ip ssh version 2 will set your SSH version to 2. This command is 

to be entered at a global configuration prompt. The command 

version 2 configured in 

the config-line prompt is incorrect. The command 

version 2 configured in the config-ssh 

prompt is incorrect as there is no config-ssh prompt. The command 

ssh version 2 is 

incorrect.

 89.  C.  The command 

transport ssh telnet will configure the VTY line to accept SSH as 

a login protocol and fall back to Telnet. The command 

login ssh telnet is incorrect. 

The command 

login ssh telnet configured in the config-line prompt is incorrect. 

The command 

transport ssh telnet configured in the global configuration prompt is 

incorrect.

 90.  D.  SSH is encrypted and Telnet is in clear text. To keep passwords and configuration 

safe, SSH should always be used. Telnet has no encryption; therefore it cannot have weak 

encryption. Although files can be transferred via SSH, replacing Telnet with SSH does not 

enable this feature. SSH does not make it easier to create ACLs for access.

 91.  B.  When you’re configuring a switch or router for SSH version 2, the key strength must 

be at least 768 bits for the modulus. The default is 512 bits, and it is standard practice to 

double the number to 1024 bits. The time and date do not need to be corrected to enable 

SSH version 2. The DNS server does not need to be configured for SSH version 2. Host 

records for the switch or router do not have to be configured for SSH version 2.

 92.  A.  The command 

username user1 password Password20! will create a user account 

called user1 with a password of Password20!. All of the other commands are incorrect.

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