Module 5
During the implementation of Spanning Tree Protocol, all switches are rebooted by the network administrator. What is the first step of the spanning-tree election process?
All the switches send out BPDUS advertising themselves as the root bridge
The port on the segment (with two switches) that has the lowest path cost to the root bridge is the:
Designated port
After the election of the root bridge has been completed, how will switches find the best paths to the root bridge?
Each switch will analyze the sum of all port costs to reach the root and use the path with the lowest cost
How often does a switch send a BPDU?
Every 2 seconds
The root bridge will be the switch with the:
Lowest bridge ID
What value determines the root bridge when all switches connected by trunk links have default STP configurations?
MAC address
What is one way to correct a spanning tree failure?
Manually remove redundant links in the switched network.
Which is the default STP operation mode on Cisco Catalyst switches?
PVST+
Which technology solves the problem of a device being unable to get an IPv4 address from a DHCP server due to STP forwarding delay timers?
PortFast
Which protocol was designed to bring faster convergence to STP?
RSTP
The sum of individual port costs along the path from the switch to the root bridge is known as the:
Root path cost
The port closest to the root bridge in terms of least overall cost (best path) to the root bridge is the:
Root port
Which statement describes STP?
STP is a Layer 2 loop prevention protocol for Ethernet LANS.
By default (without any configuration on a switch), what will determine which switch is the root bridge?
The MAC address of the switch
What additional information is contained in the 12-bit extended system ID of a BPDU?
VLAN ID
What is an accurate description of redundancy?
designing a network to use multiple paths between switches to ensure there is no single point of failure
Which port state will switch ports immediately transition to when configured for PortFast?
forwarding
When PVST is running over a switched network, which port state can participate in BPDU frame forwarding based on BPDUS received, but does not forward data frames?
listening
What device is elected by the Spanning Tree Algorithm? All other switches determine a single least-cost path to this device.
root bridge
Which STP port role is adopted by a switch port if there is no other port with a lower cost to the root bridge?
root port
An administrator is troubleshooting a switch and wants to verify if it is a root bridge. What command can be used to do this?
show spanning-tree
Which of the following ports will forward Ethernet frames? (Choose two.)
1.) Designated port 2.) Root port
Which two concepts relate to a switch port that is intended to have only end devices attached and intended never to be used to connect to another switch? (Choose two.)
1.) PortFast 2.) edge port
Which two statements describe a switch port that is configured with PortFast? (Choose two.)
1.) The switch port immediately transitions from blocking to the forwarding state 2.) The switch port should never receive BPDUs
Without STP on the Ethernet LAN, whích three types of frames could cause a catastrophic loop in the network? (Choose three.)
1.) Unknown unicast 2.) Multicast 3.) Broadcast
Which three STP port states are merged into the RSTP discarding port state? (Choose three.)
1.) disabled 2.) blocking 3.) listening
Which three port states are used by Rapid PVST+? (Choose three.)
1.) discarding 2.) forwarding 3.) learning
