Per-VLAN STP/RSTP

[sakar]

I have Cisco SG300-28, SG350-28, and Catalyst 2960 switches. SG350-28 and Catalyst 2960 are connected to SG300-28 via a trunk. The Bridge Priority of Cisco SG300-28 is set as 4096. However, the Catalyst 2960 switch sees it as root bridge only for VLAN 1 for all other VLANs the Catalyst 2960 sees itself as the root.

Cisco SMB series switches make you enter STP/RSTP Bridge Priority in the multiple of 4096 but apparently does not support Per-VLAN STP/RSTP. What is Cisco trying to do? Is there any new firmware which supports Per-VLAN STP/RSTP or am I missing something?

[balaji.bandi]

Look at the below document MST supported version :

https://www.cisco.com/c/en/us/support/docs/smb/switches/cisco-small-business-300-series-managed-switches/smb5760-configure-stp-settings-on-a-switch-through-the-cli.html

If possible post 2960 configuration, with show spanning tree output.

[sakar]

switch-2960#sh spanning-tree

VLAN0001
Spanning tree enabled protocol rstp
Root ID Priority 4096
Address b862.1fd5.a9a8
Cost 20000
Port 26 (GigabitEthernet0/2)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 32769 (priority 32768 sys-id-ext 1)
Address 8480.2d06.9f80
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300 sec

Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi0/2 Root FWD 20000 128.26 P2p

VLAN0004
Spanning tree enabled protocol rstp
Root ID Priority 32772
Address 8480.2d06.9f80
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 32772 (priority 32768 sys-id-ext 4)
Address 8480.2d06.9f80
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300 sec

Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Fa0/8 Desg FWD 200000 128.8 P2p
Fa0/13 Desg FWD 200000 128.13 P2p
Fa0/23 Desg FWD 200000 128.23 P2p
Fa0/24 Desg FWD 200000 128.24 P2p
Gi0/2 Desg FWD 20000 128.26 P2p

VLAN0010
Spanning tree enabled protocol rstp
Root ID Priority 32778
Address 8480.2d06.9f80
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 32778 (priority 32768 sys-id-ext 10)
Address 8480.2d06.9f80
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300 sec

Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Fa0/9 Desg FWD 200000 128.9 P2p
Gi0/2 Desg FWD 20000 128.26 P2p

VLAN0016
Spanning tree enabled protocol rstp
Root ID Priority 32784
Address 8480.2d06.9f80
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 32784 (priority 32768 sys-id-ext 16)
Address 8480.2d06.9f80
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300 sec

Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Fa0/7 Desg FWD 200000 128.7 P2p
Fa0/15 Desg FWD 2000000 128.15 P2p
Gi0/2 Desg FWD 20000 128.26 P2p

VLAN0074
Spanning tree enabled protocol rstp
Root ID Priority 32842
Address 8480.2d06.9f80
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 32842 (priority 32768 sys-id-ext 74)
Address 8480.2d06.9f80
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300 sec

Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi0/2 Desg FWD 20000 128.26 P2p

switch-sg-300-28#show spanning-tree

Spanning tree enabled mode RSTP
Default port cost method: long

Root ID Priority 4096
Address b8:62:1f:d5:a9:a8
This switch is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Number of topology changes 2 last change occurred 68:36:01 ago
Times: hold 1, topology change 35, notification 2
hello 2, max age 20, forward delay 15

Interfaces
Name State Prio.Nbr Cost Sts Role PortFast Type
--------- -------- --------- -------- ------ ---- -------- -----------------
gi1 enabled 128.49 2000000 Dsbl Dsbl No -
gi2 enabled 128.50 20000 Frw Desg Yes P2P (RSTP)
gi3 enabled 128.51 200000 Frw Desg Yes P2P (RSTP)
gi4 enabled 128.52 200000 Frw Desg Yes P2P (RSTP)
gi5 enabled 128.53 2000000 Dsbl Dsbl No -
gi6 enabled 128.54 200000 Frw Desg Yes P2P (RSTP)
gi7 enabled 128.55 20000 Frw Desg Yes P2P (RSTP)
gi8 enabled 128.56 200000 Frw Desg Yes P2P (RSTP)
gi9 enabled 128.57 2000000 Dsbl Dsbl No -
gi10 enabled 128.58 20000 Frw Desg Yes P2P (RSTP)
gi11 enabled 128.59 200000 Frw Desg Yes P2P (RSTP)
gi12 enabled 128.60 2000000 Dsbl Dsbl No -
gi13 enabled 128.61 20000 Frw Desg Yes P2P (RSTP)
gi14 enabled 128.62 20000 Frw Desg Yes P2P (RSTP)
gi15 enabled 128.63 2000000 Dsbl Dsbl No -
gi16 enabled 128.64 200000 Frw Desg Yes P2P (RSTP)
gi17 enabled 128.65 200000 Frw Desg Yes P2P (RSTP)
gi18 enabled 128.66 20000 Frw Desg Yes P2P (RSTP)
gi19 enabled 128.67 2000000 Frw Desg Yes P2P (RSTP)
gi20 enabled 128.68 20000 Frw Desg Yes P2P (RSTP)
gi21 enabled 128.69 20000 Frw Desg Yes P2P (RSTP)
gi22 enabled 128.70 200000 Frw Desg Yes P2P (RSTP)
gi23 enabled 128.71 20000 Frw Desg Yes P2P (RSTP)
gi24 enabled 128.72 2000000 Dsbl Dsbl No -
gi25 enabled 128.73 20000 Frw Desg Yes P2P (RSTP)
gi26 enabled 128.74 20000 Frw Desg Yes P2P (RSTP)
gi27 enabled 128.75 20000 Frw Desg No P2P (RSTP)
gi28 enabled 128.76 20000 Frw Desg No P2P (RSTP)
Po1 enabled 128.1000 20000 Dsbl Dsbl No -
Po2 enabled 128.1001 20000 Dsbl Dsbl No -
Po3 enabled 128.1002 20000 Dsbl Dsbl No -
Po4 enabled 128.1003 20000 Dsbl Dsbl No -
Po5 enabled 128.1004 20000 Dsbl Dsbl No -
Po6 enabled 128.1005 20000 Dsbl Dsbl No -
Po7 enabled 128.1006 20000 Dsbl Dsbl No -
Po8 enabled 128.1007 20000 Dsbl Dsbl No -

[nani]

I have few questions on this,

How many VLAN'S are configured on this switch?

Did you assigned any interfaces to that vlan's ?

Are the ports are UP/UP ?

Thank you,

[federacco]

I have the exact same problem. Did you solve it?