Which two statements correctly describe characteristics of the PortFast feature? (Choose two.)
A.
STP is disabled on the port.
B.
PortFast can also be configured on trunk ports.
C.
PortFast is needed to enable port-based BPDU guard.
D.
PortFast is used for STP and RSTP host ports.
E.
PortFast is used for STP-only host ports.
Explanation:
Catalyst switches offer the PortFast feature, which shortens the Listening and Learning states to a
negligible amount of time. When a workstation link comes up, the switch immediately moves the
PortFast port into the Forwarding state. Spanning-tree loop detection is still in operation, however,
and the port moves into the Blocking state if a loop is ever detected on the port. You can use
PortFast to connect a single end station or a switch port to a switch port. If you enable PortFast on
a port that is connected to another Layer 2 device, such as a switch, you might create network
loops. When PortFast is enabled between two switches, the system will verify that there are no
loops in the network before bringing the blocking trunk to a forwarding state.
Reference:
http://www.cisco.com/en/US/docs/routers/7600/ios/12.1E/configuration/guide/stp_enha.html#wp10
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