Ccna certification Practice Tests

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 158.  C.  The switch’s interface will become err-disabled immediately. Once it is in err-

disable mode, an administrator is required to reset the interface. When an interface is 

administratively disabled, it has been done by an administrator manually. The interface 

will not become disabled if a BPDU is advertised with BPDU Guard enabled; it will be err-

disabled. Fortunately, a small switching loop will be averted as the interface will be placed 

into an err-disable mode.

 159. B. The 

show spanning-tree summary command will show you which features are 

turned on globally or by default. The command 

show interface gi 0/1 is incorrect. 

The command 

show spanning-tree vlan 2 is incorrect. The command show 

spanning-tree is incorrect.

 160.  D.  BPDU Guard will protect the edge switch from someone accidentally plugging in 

another switch to a port dedicated for end devices. Spanning Tree PortFast will allow 

the interface to enter into a forwarding mode as it listens and learns BPDUs converging. 

UplinkFast helps faster convergence when an uplink fails between switches. BackboneFast 

is a Cisco proprietary protocol that improves convergence in the event an uplink fails.

 161.  B.  To achieve density and/or bandwidth in a relatively small area, you will need to deploy 

lightweight WAPs with a wireless LAN controller (WLC). Although autonomous WAPs 

without a WLC would work, it would be problematic due to frequency coordination and 

roaming. Lightweight WAPs do not function without a WLC.

 162.  D.  Cisco wireless access points can be placed into one of two modes: data serving mode 

or monitoring mode. In data serving mode, the AP will serve data and act as a normal 

wireless access point. When the AP is switched into monitor mode, the AP can scan 

the wireless spectrum and report on interference. It is important to note that when in 

monitoring mode, the AP will not serve data. The AP can be configured for both modes at 

the same time, with an impact on performance. All of the other options are incorrect.

 163.  C.  An independent basic service set (IBSS), also known as an ad hoc network, does not 

require any wireless infrastructure. Clients connect directly to each other over the 802.11 

wireless spectrum. A basic service set (BSS) is a small area with wireless coverage and is 

served by a single WAP. An extended service set (ESS) is a scaled out BSS, where many 

WAPs support client roaming between the WAPs and channel selection. The distribution 

system (DS) is the connection between the wireless network and the wired network.

 164.  B.  Non-root devices such as clients and repeaters connect to root devices such as access 

points (WAPs). Non-root devices cannot connect to other non-root devices in normal 

situations such as a network with infrastructure. Root devices do not connect to other 

root devices; they do connect to wired infrastructure. Repeaters are considered non-root 

devices.

 165.  D.  An autonomous WAP has a full operating system and controls its own functions 

independently. A lightweight WAP requires a wireless LAN controller (WLC) to function. 

A mesh wireless access point communicates with other wireless access points to extend 

distance and signal.

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