4.14 Consider the procedure to construct the spanning tree. When a bridge (with root bridge ID = w, rpc = p) receives a BPDU (with root bridge ID = m, rpc =q) from port x (with a transmission cost of c). Assume w > m. Then what will happen ?
A. (a) Port x will be selected as a new R port.
B. (b) port x will be selected as a new D port.
C. (c) A BPDU with (with root bridge ID = m, rpc =q+c) will be forwarded to all the ports, except port x.
D. (d) A BPDU with (with root bridge ID = m, rpc =q) will be forwarded to all the ports, except port x.
E. (e) A BPDU with (with root bridge ID = m, rpc =p+q) will be forwarded to all the ports, except port x.
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4.15 Consider the procedure to construct the spanning tree. When a bridge (with root bridge ID = w, rpc = p) receives a BPDU (with root bridge ID = m, rpc =q) from port x (with a transmission cost of c). Assume w ＜ m. Then what will happen ?
A. (a) Port x will be selected as a new R port.
B. (b) The BPDU will be dropped directly.
C. (c) A BPDU (with root bridge ID = w, rpc =p) will be forwarded to port x.
D. (d) A BPDU (with root bridge ID = w, rpc =q+c) will be forwarded to port x.
4.16 Consider the procedure to construct the spanning tree. When a bridge (with root bridge ID = w, rpc = p) receives a BPDU (with root bridge ID = m, rpc =q) from port x (with a transmission cost of c). Assume w = m and p > q+c. Then what will happen ?
A. (a) Port x will be selected as a new R port.
B. (b) The BPDU will be dropped directly.
C. (c) A BPDU with (with root bridge ID = m, rpc =q+c) will be forwarded to all the ports, except port x.
D. (d) A BPDU (with root bridge ID = w, rpc =q+c) will be forwarded to port x.
4.17 What is the major feature of the spanning tree constructed by the IEEE 802.1D spanning tree algorithm ?
A. (a) It is a minimum cost spanning tree. Thus, the summation of the cost of each link is minimized.
B. (b) It is a spanning tree that includes the minimum cost path of each bridge/LAN to the root bridge
C. (c) It is a spanning tree that includes the minimum cost path of each pair of bridges/LANs
D. (d) It is a minimum delay spanning tree.
4.18 Consider the procedure to maintain the spanning tree. For a bridge with three ports x,y,z and root bridge ID = w, rpc = p. Assume port x is an R port, port y is a D port of a LAN1, port z is blocked and connected to a LAN2. Which of the following statements are correct ?
A. (a) The “hello” BPDUs will be received periodically only from port x.
B. (b) The “hello” BPDUs will be received periodically from ports x and y.
C. (c) The “hello” BPDUs will be received periodically only from port z
D. (d) The “hello” BPDUs will be received periodically from ports x and z.
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