Hello everyone
I have backbone Cisco 4500 series and Just only one core switch , I have star topology and access switches are Cisco 2960.
Every SFP module connected to 2960 and It has connection from Linksys SRW248G4, and from Linksys to HP 1910
So I had PVST configuration then I have changed it to MST
But now, When I have check with show spanning-tree summary core switch shows that its root bridge for MST1 and MST0
My vlan's on MST1 and when I have checked from access switch it also shows that root bridge for MST1,
From Core switch
Summary
Switch is in mst mode
Root bridge for: MST00-MST01
Extended system ID is enabled
Portfast Default is disabled
PortFast BPDU Guard Default is disabled
Portfast BPDU Filter Default is disabled
Loopguard Default is disabled
EtherChannel misconfig guard is enabled
UplinkFast is disabled
BackboneFast is disabled
Configured Pathcost method used is short (Operational value is long)
Name Blocking Listening Learning Forwarding STP Active
---------------------- -------- --------- -------- ---------- ----------
MST00 0 0 0 32 32
MST01 0 0 0 32 32
---------------------- -------- --------- -------- ---------- ----------
2 msts 0 0 0 64 64
From Core Switch (mst detail)
###### MST00 vlans mapped: 101-4094
Bridge address 0019.aa37.8085 priority 4096 (4096 sysid 0)
Root this switch for CST and IST
Configured hello time 2, forward delay 15, max age 20, max hops 20
###### MST01 vlans mapped: 1-100
Bridge address 0019.aa37.8085 priority 1 (0 sysid 1)
Root this switch for MST01
From Core switch MST1 detail
Gi1/3 Desg FWD 20000 128.3 P2p
Gi1/4 Desg FWD 20000 128.4 P2p
Gi1/5 Desg FWD 20000 128.5 P2p
Gi1/6 Desg FWD 20000 128.6 P2p
Gi1/7 Desg FWD 20000 128.7 P2p
Gi1/8 Desg FWD 200000 128.8 P2p
Gi1/9 Desg FWD 20000 128.9 P2p
Gi1/10 Desg FWD 20000 128.10 P2p
Gi1/11 Desg FWD 200000 128.11 P2p
Gi1/12 Desg FWD 20000 128.12 P2p
From core switch show spanning tree bridge
Hello Max Fwd
MST Instance Bridge ID Time Age Dly Protocol
---------------- --------------------------------- ----- --- --- --------
MST00 4096 ( 4096, 0) 0019.aa37.8085 2 20 15 mstp
MST01 1 ( 0, 1) 0019.aa37.8085 2 20 15 mstp
And this one from access switch
Summary
Switch is in mst mode (IEEE Standard)
Root bridge for: MST1
Extended system ID is enabled
Portfast Default is disabled
PortFast BPDU Guard Default is disabled
Portfast BPDU Filter Default is disabled
Loopguard Default is enabled
EtherChannel misconfig guard is enabled
UplinkFast is disabled
BackboneFast is disabled
Configured Pathcost method used is short (Operational value is long)
Name Blocking Listening Learning Forwarding STP Active
---------------------- -------- --------- -------- ---------- ----------
MST0 0 0 0 34 34
MST1 0 0 0 34 34
---------------------- -------- --------- -------- ---------- ----------
2 msts 0 0 0 68 68
mst1 detail
##### MST1 vlans mapped: 1-100
Bridge address 0019.e79b.8090 priority 4097 (4096 sysid 1)
Root this switch for MST1
mst 0 detail
##### MST0 vlans mapped: 101-4094
Bridge address 0019.e79b.8090 priority 32768 (32768 sysid 0)
Root address 0019.aa37.8085 priority 4096 (4096 sysid 0)
port Gi0/1 path cost 20000
Regional Root address ec44.76d3.8091 priority 32768 (32768 sysid 0)
internal cost 20000 rem hops 19
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
I had same mst configuration core and access switches same region name, instance 1,revision same. Im sure about this, I have checked many time.
Whats Wrong ?
Im waiting for answer
Best Regards.
