Why has this switch not been elected the root bridge for VLAN1?

Refer to the exhibit.

Why has this switch not been elected the root bridge for VLAN1?

Refer to the exhibit.

Why has this switch not been elected the root bridge for VLAN1?

A.
It has more than one interface that is connected to the root network segment.

B.
It is running RSTP while the elected root bridge is running 802.1d spanning tree.

C.
It has a higher MAC address than the elected root bridge.

D.
It has a higher bridge ID than the elected root bridge.



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Bilzerian

Bilzerian

Hey admin, all of your links to the picture files are jacked up. You have .png files, but you linked to .jpg files. Fix your shit.

miltux

miltux

Just took this exam last week and scored a 947. This exam prep is still valid and right on the money! Thank you aiotestking! you guys rock!

Jay Z

Jay Z

When a switch receives a BPDU, it first compares priority, the lower number wins. If
a tie, compare MAC, the smaller one wins. Here Switch has 32769 priority which is greater than
20481 so switch will not elect for root bridge. It says the bridge priority for Switch is 32769, and the
root priority is 20481. Which means that some other switch has the lower priority and won the
election for VLAN 1.
The following criteria are used by each spanning tree node to select a path to the root bridge:

Lowest root bridge ID – Determines the root bridge
Lowest cost to the root bridge – Favors the upstream switch with the least cost to root
Lowest sender bridge ID – Serves as a tie breaker if multiple upstream switches have equal cost to root
Lowest sender port ID – Serves as a tie breaker if a switch has multiple (non-Etherchannel) links to a single upstream switch

miltux

miltux

A bridge protocol data unit (BPDU) is a data message transmitted across a local area network to detect loops in network topologies. A BPDU contains information regarding ports, switches, port priority and addresses. BPDUs contain the information necessary to configure and maintain spanning tree topology.

hu

hu

Bridge ID priority is higher than root ID priority