Refer to the Exhibit.
Based on the topology and configurations shown in the exhibit, which two statements are true? (Choose two.)
A.
Switch-3 will be elected the root bridge.
B.
Both of Switch-1’s interfaces will assume the forwarding state.
C.
Switch-2 will be elected the root bridge.
D.
Both of Switch-3’s interfaces will assume the forwarding state.
Explanation:
The original Spanning Tree Protocol is defined in the IEEE 802.1D 1998 specification. A newer version called Rapid Spanning Tree Protocol (RSTP) was originally defined in the IEEE 802.1w draft specification and later incorporated into the IEEE 802.1D-2004 specification.RSTP provides faster reconvergence time than the original STP by identifying certain links as point-to-point and by using protocol handshake messages rather than fixed timeouts. When a point-to-point link fails, the alternate link can transition to the forwarding state without waiting for any protocol timers to expire. Consequently, RSTP convergence is approximately 50 milliseconds for point-to-point links.
Port operation is similar between STP and RSTP. In both, the state of the port is variable, and determines if the port blocks or forwards traffic. Additionally, the role a port plays in the active topology varies, if it is calculated to be a root port, a designated port, and so on.
For example, in STP there are no operational differences between a port in the blocking state and a port in the listening state. Both port states discard frames and do not learn MAC addresses. The real difference is in the role the spanning tree assigns to the port. You can assume that a listening port is either a designated port or a root port, and is in the process of transitioning to the forwarding state. Once in the forwarding state, there is no way to infer from the port state whether the port is root or designated.