Exam 350-401 topic 1 question 164 discussion

To configure DSW1 as the root bridge for VLANs 10 and 20 in spanning-tree instance '1', you can use either of the following commands: - spanning-tree mst 1 priority 4096 This command sets the bridge priority for MST instance '1' to 4096. The bridge priority values range from 0 to 61440 and must be a multiple of 4096. A lower value indicates a higher priority for becoming the root bridge, thereby forcing DSW1 to be elected as the root switch for MST instance '1'. - spanning-tree mst 1 root primary This command designates DSW1 as the primary root bridge for MST instance '1'. It ensures DSW1 is elected as the root bridge regardless of its current MAC address or bridge priority.

A & B are correct

in Global config (c)# spanning-tree instanceID# root {primary | secondary} (c)# spanning-tree instanceID# priority {increment of 4096} default is 32768 Only time "vlan" is used is when you are configuring an instance in mst configuration making choice E incorrect

! spanning-tree mode mst spanning-tree extend system-id ! spanning-tree mst configuration name region_1 revision 2 instance 1 vlan 1-30 instance 2 vlan 31-110 ! ! sw2(config)#do s spann mst ##### MST1 vlans mapped: 1-30 Bridge address aabb.cc00.4000 priority 32769 (32768 sysid 1) Root address aabb.cc00.1000 priority 32769 (32768 sysid 1) port Po2 cost 2000000 rem hops 19 Interface Role Sts Cost Prio.Nbr Type ---------------- ---- --- --------- -------- -------------------------------- Et0/0 Desg FWD 2000000 128.1 Shr Edge Et0/2 Desg FWD 2000000 128.3 Shr Et0/3 Altn BLK 2000000 128.4 Shr Po2 Root FWD 2000000 128.65 Shr ##### MST2

correct 100%

why not D and E?

The 2 ways to manipulate the configuration of the root bridge is by using the “spanning-tree mst instance-id priority value” command manually or the “spanning-tree mst instance-id root ( primary | secondary )” command. If using the priority command you must set the ID in multiples of 4096.

always we have to put a number after mst priority should be increment of 4096

always we have to put a number after mst , priority should be incrent 4096

Provided answer is correct

A E ? maybe

Given answer is corect