READ Free Dumps For Cisco- 200-125
| Question ID 13530 | Which switch would STP choose to become the root bridge in the selection process?
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| Option A | 32768: 11-22-33-44-55-66
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| Option B | 32768: 22-33-44-55-66-77
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| Option C | 32769: 11-22-33-44-55-65
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| Option D | 32769: 22-33-44-55-66-78
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| Correct Answer | A |
Explanation Explanation: The root bridge of the spanning tree is the bridge with the smallest (lowest) bridge ID. Each bridge has a configurable priority number and a MAC Address; the bridge ID contains both numbers combined together - Bridge priority + MAC (32768.0200.0000.1111). The Bridge priority default is 32768 and can only be configured in multiples of 4096(Spanning tree uses the 12 bits extended system ID). To compare two bridge IDs, the priority is compared first, as if looking at a real number anything less than 32768...will become the target of being the root. If two bridges have equal priority then the MAC addresses are compared; for example, if switches A (MAC=0200.0000.1111) and B (MAC=0200.0000.2222) both have a priority of 32768 then switch A will be selected as the root bridge. In this case, 32768: 11-22-33-44-55-66 would be the bridge because it has a lower priority and MAC address.
| Question ID 13531 | Refer to the exhibit.
Why has this switch not been elected the root bridge for VLAN1?
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| Option A | It has more than one interface that is connected to the root network segment.
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| Option B | It is running RSTP while the elected root bridge is running 802.1d spanning tree.
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| Option C | It has a higher MAC address than the elected root bridge.
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| Option D | It has a higher bridge ID than the elected root bridge.
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| Correct Answer | D |
Explanation Explanation: The root bridge is determined by the lowest bridge ID, and this switch has a bridge ID priority of 32768, which is higher than the roots priority of 20481.