Which of the following describe the BIDs used in a
spanning tree topology? (Choose two.)
They are sent out by the root
bridge only after the inferior BPDUs are sent.
They consist of a bridge priority
and MAC address.
Only the root bridge will send out
a BID.
They are used by the switches in a
spanning tree topology to elect the root bridge.
The switch with the fastest
processor will have the lowest BID.
2
Which algorithm is used to create a loop free switched
topology?
Spanning Tree
Shortest Path First
Dykstra
Rapid Tree
Bellman-Ford
3
What is meant by "five nines" network
uptime?
A network should be available until
9:00 pm five days of the week.
A network should be functioning
99.999% of the time.
There should be five nine-port
uplinks for each backbone segment.
Five percent of network
expenditures should address 99% of user requirements.
Nothing short of 100% network
uptime is acceptable in modern
networks.
4
Switch_A and Switch_B shown in the graphic receive an
ARP request from the host and forward it out their ports. The
switches receive the forwarded requests from each other and in turn
flood the requests again. What will be the result if this process
continues?
a broadcast storm
multicast errors
ARP table errors
MAC address instability
redundant unicast frame
forwarding
5
Which of the following are valid STP port states?
(Choose three.)
blocking
learning
converging
listening
switching
6
How often are BPDUs sent by default in a network using
the spanning-tree algorithm?
every second
every two seconds
every three seconds
every four
seconds
7
What happens when there is a topology change on a
network that utilizes STP ? (Choose two.)
User traffic is disrupted until
recalculation is complete.
The switch recomputes the Spanning
Tree topology after the network converges.
All ports are placed in learning
state until convergence has occurred.
A delay of up to 50 seconds is
incurred for convergence of the new Spanning Tree topology.
User data is forwarded while BPDUs
are exchanged to recompute the
topology.
8
How can a network administrator influence which STP
switch becomes the root bridge?
Configure the switch as the static
root bridge.
Change the BPDU to a higher value
than that of the other switches in the network.
Change the BPDU to a lower value
than that of the other switches in the network.
Set the switch priority to a
smaller value than that of the other switches in the network.
Set the switch priority to a higher
value than that of the other switches in the
network.
9
What features of the Spanning-Tree Protocol contribute
to the time it takes for a switched network to converge after a
topology change occurs? (Choose three.)
the max-age timer
the listening forward delay
the spanning-tree hold down
timer
the learning forward delay
the spanning-tree path cost
the blocking
delay
10
How does a switch forward a multicast frame through
the network?
It floods it to all ports as a
broadcast.
It is forwarded only to ports that
contain the destination address.
It is sent to the port that
contains the first destination address.
It floods it to all ports except
the one it was received on.
It is dropped and not sent to any
address.
11
Following a link failure, when does Rapid Spanning
Tree Protocol allow point-to-point and edge type links to go to the
forwarding state?
in 15 seconds
never
immediately
in 30 seconds
after 90
seconds
12
What is the first step in the process of convergence
in a spanning tree topology?
election of the root bridge
determination of the designated
port for each segment
blocking of the non-designated
ports
selection of the designated trunk
port
activation of the root port for
each segment
13
What link types have been defined for Rapid
Spanning-Tree Protocol? (Choose three.)
shared
end-to-end
edge-type
boundary-type
point-to-many
point-to-point
14
What characteristic of Ethernet makes a redundantly
switched network prone to loops?
Routers are only able to prevent
loops at Layer 3, while Ethernet exists at Layer 2.
The Ethernet protocol has no TTL
mechanism.
Switches lack the sophisticated
software required to prevent loops.
Looping of frames is a reliability
mechanism built in to the Ethernet
protocol.
15
In which STP state does a switch port transmit user
data and learn MAC addresses?
blocking
learning
disabling
listening
forwarding
16
In which STP state does a port record MAC addresses
but not forward user data?
blocking
learning
disabling
listening
forwarding
17
Which of the following criteria does a switch use to
select the root bridge? (Choose two.)
memory size
bridge priority
switching speed
number of ports
base MAC address
switch
location
18
What elements will exist in a converged network with
one spanning tree? (Choose two.)
one root bridge per network
all non-designated ports
forwarding
one root port per non-root
bridge
multiple designated ports per
segment
one designated port per
network
19
Refer to the network shown in the graphic. Host1 needs
to transfer data to host2, but host1 has no MAC address entry in its
ARP cache for host2. What will happen on the network as host1
prepares to transmit its data to host2?
Host1 will receive an ICMP
destination unknown message from switch3.
All hosts in the network shown will
receive an ARP request message from host1.
Multicasting will occur until host2
is located.
Switch3 will send the host2 MAC
address from its bridging table to host1.
A broadcast storm will
occur.
20
How much time does it take for a switch port to go
from the blocking state to the forwarding state?
2 seconds
15 seconds
20 seconds
50
seconds
21
Refer to the graphic. Server sends an ARP request for
the MAC address of its default gateway. If STP is not enabled, what
will be the result of this ARP request?
Router_1 will kill the broadcast
and reply with the MAC address of the next hop router.
Switch_A will reply with the MAC
address of the Router_1 E0 interface.
Switch_A and Switch_B will
continuously flood the message onto the network.
Switch_B will broadcast the request
and reply with the Router_1 address.
The message will cycle around the
network until its TTL is exceeded.
22
Which of the following are problems that can occur in
redundantly switched networks? (Choose three.)
broadcast storms
corrupted ARP tables
duplicate MAC addresses
inaccurate routing tables
multiple copies of Ethernet
frames
MAC address table
instability
23
How is the information contained in BPDUs used by
switches? (Choose two.)
to prevent loops by sharing
bridging tables between connected switches
to set the duplex mode of a
redundant link
to determine the shortest path to
the root bridge
to determine which ports will
forward frames as part of the spanning tree
