http://www.juniper.net/techpubs/en_US/junos12.3/topics/concept/mx-series-multiple-stp.html
"The CIST regional root is also the CIST root if there is only one region in the network."
I have a single region - matching vlan/mst table (via digest) / revision / name
Between a Cisco nexus vPC pair and EX ring.
Pretty much default configs, with the Cisco being the root for CIST (and thus region as well).
Nexus thinks it's root of CIST+CIST regional root (as wanted).
Juniper thinks it's the CIST regional root. CIST root is correct.
Any suggestions?
cisco# show run spanning-tree
spanning-tree mode mst
spanning-tree pathcost method long
spanning-tree mst 0 priority 4096
spanning-tree mst configuration
name qa-zcq
cisco# show spanning-tree mst configuration digest
Name [qa-zcq]
Revision 0 Instances configured 1
Digest 0xac36177f50283cd4b83821d8ab26de62
cisco# show spanning-tree mst
##### MST0 vlans mapped: 1-4094
Bridge address 0023.04ee.be14 priority 4096 (4096 sysid 0)
Root this switch for the CIST
Regional Root this switch
Operational hello time 2 , forward delay 15, max age 20, txholdcount 6
Configured hello time 2 , forward delay 15, max age 20, max hops 20
Interface Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Po5 Desg FWD 250 128.4100 (vPC peer-link) Network P2p
Po20 Desg FWD 200 128.4115 (vPC) Edge P2p
Po21 Desg FWD 200 128.4116 (vPC) Edge P2p
Po22 Desg FWD 200 128.4117 (vPC) Edge P2p
Po23 Desg FWD 200 128.4118 (vPC) Edge P2p
Po24 Desg FWD 200 128.4119 (vPC) P2p Bound(PVST)
Eth1/12 Desg FWD 2000 128.12 P2p
Eth1/13 Desg FWD 2000 128.13 P2p
mbeck@juniper> show configuration | display set | match stp
set protocols stp disable
set protocols rstp disable
set protocols mstp configuration-name qa-zcq
mbeck@juniper> show spanning-tree mstp configuration
MSTP information
Context identifier : 0
Region name : qa-zcq
Revision : 0
Configuration digest : 0xac36177f50283cd4b83821d8ab26de62
MSTI Member VLANs
0 0-4094
mbeck@juniper> show spanning-tree bridge
STP bridge parameters
Context ID : 0
Enabled protocol : MSTP
STP bridge parameters for CIST
Root ID : 4096.00:23:04:ee:be:14
Root cost : 1000
Root port : ae1.0
CIST regional root : 32768.5c:45:27:b6:e3:01
CIST internal root cost : 0
Hello time : 2 seconds
Maximum age : 20 seconds
Forward delay : 15 seconds
Hop count : 20
Message age : 1
Number of topology changes : 11
Time since last topology change : 20991 seconds
Topology change initiator : ae1.0
Topology change last recvd. from : 00:26:f0:18:00:00
Local parameters
Bridge ID : 32768.5c:45:27:b6:e3:01
Extended system ID : 0
Internal instance ID : 0