Question :A company is experiencing network delays. The network administrator discovers
that a worker in a location far from the MDF has connected an old 10BASE-T
switch with redundant links to the existing network. How could this action be
responsible for the impaired network performance?
A. Connecting a host to the old switch has created a broadcast storm.
B. The 10BASE-T switch forced the entire network to be reduced to 10 Mbps operation.
C. The old switch does not support VLANs, which has disabled the VLAN configuration
of the entire the network.
D. The old switch does not support full-duplex operation, effectively forcing half-duplex
operation throughout the network.
E. Spanning Tree Protocol has elected the old switch as the root bridge, creating
inefficient data paths through the switched network.
Answer :E
Explanation:
Without the Spanning Tree Protocol (STP), frames would loop for an indefinite period of time in networks
with physically redundant links. To prevent looping frames, STP blocks some ports from forwarding frames
so that only one active path exists between any pair of LAN segments (collision domains). The result of
STP is good: Frames do not loop infinitely, which makes the LAN usable. However, the network uses some
redundant links in case of a failure, but not for balancing traffic.
To avoid loops, all bridging devices, including switches, use STP. STP causes each interface on a bridging
device to settle into a blocking state or a forwarding state. Blocking means that the interface cannot forward
or receive data frames. Forwarding means that the interface can send and receive data frames. By having a
correct subset of the interfaces blocked, a single currently active logical path will exist between each pair of
LANs. STP behaves identically for a transparent bridge and a switch. So, the terms bridge, switch, and
bridging device all are used interchangeably when discussing STP.
Leading the way in IT testing and certification tools, www.testking.com
- 509 -
Root bridge The root
bridge is the bridge with
the best bridge ID. With
STP, the key is for all the
switches in the network
to elect a root bridge that
becomes the focal point
in the network. All other
decisions in the
network-like which port
is to be blocked
that a worker in a location far from the MDF has connected an old 10BASE-T
switch with redundant links to the existing network. How could this action be
responsible for the impaired network performance?
A. Connecting a host to the old switch has created a broadcast storm.
B. The 10BASE-T switch forced the entire network to be reduced to 10 Mbps operation.
C. The old switch does not support VLANs, which has disabled the VLAN configuration
of the entire the network.
D. The old switch does not support full-duplex operation, effectively forcing half-duplex
operation throughout the network.
E. Spanning Tree Protocol has elected the old switch as the root bridge, creating
inefficient data paths through the switched network.
Answer :E
Explanation:
Without the Spanning Tree Protocol (STP), frames would loop for an indefinite period of time in networks
with physically redundant links. To prevent looping frames, STP blocks some ports from forwarding frames
so that only one active path exists between any pair of LAN segments (collision domains). The result of
STP is good: Frames do not loop infinitely, which makes the LAN usable. However, the network uses some
redundant links in case of a failure, but not for balancing traffic.
To avoid loops, all bridging devices, including switches, use STP. STP causes each interface on a bridging
device to settle into a blocking state or a forwarding state. Blocking means that the interface cannot forward
or receive data frames. Forwarding means that the interface can send and receive data frames. By having a
correct subset of the interfaces blocked, a single currently active logical path will exist between each pair of
LANs. STP behaves identically for a transparent bridge and a switch. So, the terms bridge, switch, and
bridging device all are used interchangeably when discussing STP.
Leading the way in IT testing and certification tools, www.testking.com
- 509 -
Root bridge The root
bridge is the bridge with
the best bridge ID. With
STP, the key is for all the
switches in the network
to elect a root bridge that
becomes the focal point
in the network. All other
decisions in the
network-like which port
is to be blocked