— Exhibit –
— Exhibit —
Click the Exhibit button.
Referring to the exhibit and based on the output below from Sw-1 and Sw-2, which statement is
true?
Sw-1> show spanning-tree mstp configuration
MSTP information
Context identifier : 0
Region name : juniper
Revision : 1
Configuration digest : 0x9357ebb7a8d74dd5fef4f2bab50531aa
MSTI Member VLANs
0 0-9,11-19,21-4094
1 10
2 20
Sw-2# run show spanning-tree mstp configuration
MSTP information
Context identifier : 0
Region name : juniper
Revision : 1
Configuration digest : 0x387b5f2ea2394b14e091f0921ee7b9a8
MSTI Member VLANs
0 0-9,11-14,16-19,21-4094
1 10,15
2 20
A.
There will be only one MSTI 2 root bridge.
B.
There will be only one CST root bridge.
C.
Sw-1 and Sw-2 are in different MSTP regions.
D.
There will be only one CIST root bridge.
This answer is correct
https://kb.juniper.net/InfoCenter/index?page=content&id=KB21536
Looking at the link you have provided, it is clear, that answer D is correct:
“If the MSTP configuration between two switches differ, CIST (Common Spanning Tree) will converge; but MST Instances will not converge, as the configuration’s Digest Value will not match.”
Will converge == one root bridge.
They are in different regions
configuration digest # are different
the region is clearly the same juniper. if the question was like ‘which is false’ I would go with C.
Koraa, you are correct.
I think the answer is A.
The answer is A as per that attached link by JM..there will be 2 MST root bridges
D
agree D
MSTP creates a Common and Internal Spanning-Tree (CIST) to interconnect and manage all MSTP regions and even individual devices that run RSTP or STP, which are recognized as distinct spanning-tree regions by MSTP. The CIST views each MSTP region as a virtual bridge, regardless of the actual number of devices participating in the MSTP region, and enables MSTIs to link to other regions.
The CIST is a single topology that connects all switches (STP, RSTP, and MSTP devices) through an active topology, ensuring connectivity between LANs and devices within a bridged network.
https://www.juniper.net/documentation/en_US/junos12.3/topics/concept/spanning-trees-ex-series-mstp-understanding.html