root bridge must be in MST
初期設定
・全ポートトランク
・各SW間でLAGを組む
・SW1(config)#span vlan 1-4094 prio 4096でSW1をルートブリッジにする
SW1#sh span
VLAN0001
Spanning tree enabled protocol ieee
Root ID Priority 4097
Address 0cf6.d6fb.0000
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 4097 (priority 4096 sys-id-ext 1)
Address 0cf6.d6fb.0000
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 15 sec
Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi0/0 Desg FWD 4 128.1 P2p
Gi1/3 Desg FWD 4 128.8 P2p
Gi2/0 Desg FWD 4 128.9 P2p
Gi2/1 Desg FWD 4 128.10 P2p
Gi2/2 Desg FWD 4 128.11 P2p
Gi2/3 Desg FWD 4 128.12 P2p
Gi3/0 Desg FWD 4 128.13 P2p
Gi3/1 Desg FWD 4 128.14 P2p
Gi3/2 Desg FWD 4 128.15 P2p
Gi3/3 Desg FWD 4 128.16 P2p
Po13 Desg FWD 3 128.65 P2p
Po14 Desg FWD 3 128.66 P2p
Po12 Desg FWD 3 128.67 P2p本題
SW1のみMSTを設定しない
/ # ping 10.0.10.2
PING 10.0.10.2 (10.0.10.2) 56(84) bytes of data.
From 10.0.10.1 icmp_seq=1 Destination Host Unreachable
From 10.0.10.1 icmp_seq=2 Destination Host Unreachable
From 10.0.10.1 icmp_seq=3 Destination Host Unreachable
From 10.0.10.1 icmp_seq=4 Destination Host Unreachable
From 10.0.10.1 icmp_seq=5 Destination Host Unreachable
全SWでMSTを起動
/ # ping 10.0.10.2
PING 10.0.10.2 (10.0.10.2) 56(84) bytes of data.
64 bytes from 10.0.10.2: icmp_seq=1 ttl=64 time=9.62 ms
64 bytes from 10.0.10.2: icmp_seq=2 ttl=64 time=5.84 ms
64 bytes from 10.0.10.2: icmp_seq=3 ttl=64 time=5.74 ms
64 bytes from 10.0.10.2: icmp_seq=4 ttl=64 time=5.73 msINEのQuizで「root bridge must be in MST」とあったので検証。SW1のみプライオリティを4096に設定してルートブリッジにしてからMSTをSW2~4に設定すると、SW1-2を経由するホスト間での通信ができなくなった。
SW1もMSTに所属させると疎通できるようになる。
因みに、ルートブリッジはMSTに所属していて、それ以外のスイッチはMSTに所属していない場合はpingが通る。つまり、MSTを起動する際は少なくともルートブリッジだけはMSTに所属していないといけない。
以下、場合わけしてshow spanとshow span mstを確認する。
ルートブリッジ(SW1)以外をMSTにする
設定
SW2(config)#span mode mst
SW2(config)#span mst config
SW2(config-mst)#instance 1 vlan 1-100
SW2(config-mst)#instance 2 vlan 101-200
SW2(config-mst)#instance 3 vlan 201-300
SW2(config-mst)#name CISCO
SW2(config-mst)#revision 1
SW2(config-mst)#show pending
Pending MST configuration
Name [CISCO]
Revision 1 Instances configured 4
Instance Vlans mapped
-------- ---------------------------------------------------------------------
0 301-4094
1 1-100
2 101-200
3 201-300
-------------------------------------------------------------------------------
(SW3,4にも同様の設定)SW1: show span (show span mstはまだ存在しない)
SW1#sh span
VLAN0001
Spanning tree enabled protocol ieee
Root ID Priority 4097
Address 0cf6.d6fb.0000
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 4097 (priority 4096 sys-id-ext 1)
Address 0cf6.d6fb.0000
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 15 sec
Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi0/0 Desg FWD 4 128.1 P2p
Gi1/3 Desg FWD 4 128.8 P2p
Gi2/0 Desg FWD 4 128.9 P2p
Gi2/1 Desg FWD 4 128.10 P2p
Gi2/2 Desg FWD 4 128.11 P2p
Gi2/3 Desg FWD 4 128.12 P2p
Gi3/0 Desg FWD 4 128.13 P2p
Gi3/1 Desg FWD 4 128.14 P2p
Gi3/2 Desg FWD 4 128.15 P2p
Gi3/3 Desg FWD 4 128.16 P2p
Po13 Desg FWD 3 128.65 P2p
Po14 Desg FWD 3 128.66 P2p
Po12 Desg FWD 3 128.67 P2p SW2: show span mst
SW2#sh span mst
##### MST0 vlans mapped: 301-4094
Bridge address 0c08.45ec.0000 priority 32768 (32768 sysid 0)
Root address 0cf6.d6fb.0000 priority 4097 (4096 sysid 1)
port Po12 path cost 10000
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
---------------- ---- --- --------- -------- --------------------------------
Gi0/0 Desg FWD 20000 128.1 P2p
Gi1/3 Desg FWD 20000 128.8 P2p
Gi2/0 Desg FWD 20000 128.9 P2p
Gi2/1 Desg FWD 20000 128.10 P2p
Gi2/2 Desg FWD 20000 128.11 P2p
Gi2/3 Desg FWD 20000 128.12 P2p
Gi3/0 Desg FWD 20000 128.13 P2p
Gi3/1 Desg FWD 20000 128.14 P2p
Gi3/2 Desg FWD 20000 128.15 P2p
Gi3/3 Desg FWD 20000 128.16 P2p
Po12 Root FWD 10000 128.65 P2p Bound(STP)
Po24 Desg FWD 10000 128.66 P2p
Po23 Desg FWD 10000 128.67 P2p
##### MST1 vlans mapped: 1-100
Bridge address 0c08.45ec.0000 priority 32769 (32768 sysid 1)
Root this switch for MST1
Interface Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Gi0/0 Desg FWD 20000 128.1 P2p
Gi1/3 Desg FWD 20000 128.8 P2p
Gi2/0 Desg FWD 20000 128.9 P2p
Gi2/1 Desg FWD 20000 128.10 P2p
Gi2/2 Desg FWD 20000 128.11 P2p
Gi2/3 Desg FWD 20000 128.12 P2p
Gi3/0 Desg FWD 20000 128.13 P2p
Gi3/1 Desg FWD 20000 128.14 P2p
Gi3/2 Desg FWD 20000 128.15 P2p
Gi3/3 Desg FWD 20000 128.16 P2p
Po12 Mstr FWD 10000 128.65 P2p Bound(STP)
Po24 Desg FWD 10000 128.66 P2p
Po23 Desg FWD 10000 128.67 P2p明示的に指定されていないvlanが所属するMST0ではSW1がルートブリッジになり、MSTコンフィグモードで設定したMST1ではSW2がルートブリッジになる（そもそもSW1にはMST1が存在しない）。
また、SW1と接続しているport-channel 12のTypeに対抗が異なるSTPモードで動いていることを示す”Bound”が付いている。
SW2: show span
SW2#sh span
MST0
Spanning tree enabled protocol mstp
Root ID Priority 4097
Address 0cf6.d6fb.0000
Cost 10000
Port 65 (Port-channel12)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32768 (priority 32768 sys-id-ext 0)
Address 0c08.45ec.0000
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi0/0 Desg FWD 20000 128.1 P2p
Gi1/3 Desg FWD 20000 128.8 P2p
Gi2/0 Desg FWD 20000 128.9 P2p
Gi2/1 Desg FWD 20000 128.10 P2p
Gi2/2 Desg FWD 20000 128.11 P2p
Gi2/3 Desg FWD 20000 128.12 P2p
Gi3/0 Desg FWD 20000 128.13 P2p
Gi3/1 Desg FWD 20000 128.14 P2p
Gi3/2 Desg FWD 20000 128.15 P2p
Gi3/3 Desg FWD 20000 128.16 P2p
Po12 Root FWD 10000 128.65 P2p Bound(STP)
Po24 Desg FWD 10000 128.66 P2p
Po23 Desg FWD 10000 128.67 P2p
MST1
Spanning tree enabled protocol mstp
Root ID Priority 32769
Address 0c08.45ec.0000
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32769 (priority 32768 sys-id-ext 1)
Address 0c08.45ec.0000
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi0/0 Desg FWD 20000 128.1 P2p
Gi1/3 Desg FWD 20000 128.8 P2p
Gi2/0 Desg FWD 20000 128.9 P2p
Gi2/1 Desg FWD 20000 128.10 P2p
Gi2/2 Desg FWD 20000 128.11 P2p
Gi2/3 Desg FWD 20000 128.12 P2p
Gi3/0 Desg FWD 20000 128.13 P2p
Gi3/1 Desg FWD 20000 128.14 P2p
Gi3/2 Desg FWD 20000 128.15 P2p
Gi3/3 Desg FWD 20000 128.16 P2p
Po12 Mstr FWD 10000 128.65 P2p Bound(STP)
Po24 Desg FWD 10000 128.66 P2p
Po23 Desg FWD 10000 128.67 P2p SW1もMSTにする（instanceは作らない）
設定
SW1(config)#span mode mstSW1: show span
SW1#sh span
MST0
Spanning tree enabled protocol mstp
Root ID Priority 32768
Address 0c08.45ec.0000
Cost 10000
Port 67 (Port-channel12)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32768 (priority 32768 sys-id-ext 0)
Address 0cf6.d6fb.0000
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi0/0 Desg FWD 20000 128.1 P2p
Gi1/3 Desg FWD 20000 128.8 P2p
Gi2/0 Desg FWD 20000 128.9 P2p
Gi2/1 Desg FWD 20000 128.10 P2p
Gi2/2 Desg FWD 20000 128.11 P2p
Gi2/3 Desg FWD 20000 128.12 P2p
Gi3/0 Desg FWD 20000 128.13 P2p
Gi3/1 Desg FWD 20000 128.14 P2p
Gi3/2 Desg FWD 20000 128.15 P2p
Gi3/3 Desg FWD 20000 128.16 P2p
Po13 Altn BLK 10000 128.65 P2p Bound(RSTP)
Po14 Altn BLK 10000 128.66 P2p Bound(RSTP)
Po12 Root FWD 10000 128.67 P2p Bound(RSTP)全てのvlanでルートブリッジがSW2になる。
SW1: show span mst
SW1#sh span mst
##### MST0 vlans mapped: 1-4094
Bridge address 0cf6.d6fb.0000 priority 32768 (32768 sysid 0)
Root address 0c08.45ec.0000 priority 32768 (32768 sysid 0)
port Po12 path cost 10000
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
---------------- ---- --- --------- -------- --------------------------------
Gi0/0 Desg FWD 20000 128.1 P2p
Gi1/3 Desg FWD 20000 128.8 P2p
Gi2/0 Desg FWD 20000 128.9 P2p
Gi2/1 Desg FWD 20000 128.10 P2p
Gi2/2 Desg FWD 20000 128.11 P2p
Gi2/3 Desg FWD 20000 128.12 P2p
Gi3/0 Desg FWD 20000 128.13 P2p
Gi3/1 Desg FWD 20000 128.14 P2p
Gi3/2 Desg FWD 20000 128.15 P2p
Gi3/3 Desg FWD 20000 128.16 P2p
Po13 Altn BLK 10000 128.65 P2p Bound(RSTP)
Po14 Altn BLK 10000 128.66 P2p Bound(RSTP)
Po12 Root FWD 10000 128.67 P2p Bound(RSTP) SW2: show span mst
SW2#sh span mst
##### MST0 vlans mapped: 301-4094
Bridge address 0c08.45ec.0000 priority 32768 (32768 sysid 0)
Root this switch for the CIST
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
---------------- ---- --- --------- -------- --------------------------------
Gi0/0 Desg FWD 20000 128.1 P2p
Gi1/3 Desg FWD 20000 128.8 P2p
Gi2/0 Desg FWD 20000 128.9 P2p
Gi2/1 Desg FWD 20000 128.10 P2p
Gi2/2 Desg FWD 20000 128.11 P2p
Gi2/3 Desg FWD 20000 128.12 P2p
Gi3/0 Desg FWD 20000 128.13 P2p
Gi3/1 Desg FWD 20000 128.14 P2p
Gi3/2 Desg FWD 20000 128.15 P2p
Gi3/3 Desg FWD 20000 128.16 P2p
Po12 Desg FWD 10000 128.65 P2p
Po24 Desg FWD 10000 128.66 P2p
Po23 Desg FWD 10000 128.67 P2p
##### MST1 vlans mapped: 1-100
Bridge address 0c08.45ec.0000 priority 32769 (32768 sysid 1)
Root this switch for MST1
Interface Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Gi0/0 Desg FWD 20000 128.1 P2p
Gi1/3 Desg FWD 20000 128.8 P2p
Gi2/0 Desg FWD 20000 128.9 P2p
Gi2/1 Desg FWD 20000 128.10 P2p
Gi2/2 Desg FWD 20000 128.11 P2p
Gi2/3 Desg FWD 20000 128.12 P2p
Gi3/0 Desg FWD 20000 128.13 P2p
Gi3/1 Desg FWD 20000 128.14 P2p
Gi3/2 Desg FWD 20000 128.15 P2p
Gi3/3 Desg FWD 20000 128.16 P2p
Po12 Desg FWD 10000 128.65 P2p
Po24 Desg FWD 10000 128.66 P2p
Po23 Desg FWD 10000 128.67 P2pSW2: show span
SW2#sh span
MST0
Spanning tree enabled protocol mstp
Root ID Priority 32768
Address 0c08.45ec.0000
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32768 (priority 32768 sys-id-ext 0)
Address 0c08.45ec.0000
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi0/0 Desg FWD 20000 128.1 P2p
Gi1/3 Desg FWD 20000 128.8 P2p
Gi2/0 Desg FWD 20000 128.9 P2p
Gi2/1 Desg FWD 20000 128.10 P2p
Gi2/2 Desg FWD 20000 128.11 P2p
Gi2/3 Desg FWD 20000 128.12 P2p
Gi3/0 Desg FWD 20000 128.13 P2p
Gi3/1 Desg FWD 20000 128.14 P2p
Gi3/2 Desg FWD 20000 128.15 P2p
Gi3/3 Desg FWD 20000 128.16 P2p
Po12 Desg FWD 10000 128.65 P2p
Po24 Desg FWD 10000 128.66 P2p
Po23 Desg FWD 10000 128.67 P2p
MST1
Spanning tree enabled protocol mstp
Root ID Priority 32769
Address 0c08.45ec.0000
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32769 (priority 32768 sys-id-ext 1)
Address 0c08.45ec.0000
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi0/0 Desg FWD 20000 128.1 P2p
Gi1/3 Desg FWD 20000 128.8 P2p
Gi2/0 Desg FWD 20000 128.9 P2p
Gi2/1 Desg FWD 20000 128.10 P2p
Gi2/2 Desg FWD 20000 128.11 P2p
Gi2/3 Desg FWD 20000 128.12 P2p
Gi3/0 Desg FWD 20000 128.13 P2p
Gi3/1 Desg FWD 20000 128.14 P2p
Gi3/2 Desg FWD 20000 128.15 P2p
Gi3/3 Desg FWD 20000 128.16 P2p
Po12 Desg FWD 10000 128.65 P2p
Po24 Desg FWD 10000 128.66 P2p
Po23 Desg FWD 10000 128.67 P2p SW1でinstanceを作る
SW1: show span
SW1#sh span
MST0
Spanning tree enabled protocol mstp
Root ID Priority 32768
Address 0c08.45ec.0000
Cost 0
Port 67 (Port-channel12)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32768 (priority 32768 sys-id-ext 0)
Address 0cf6.d6fb.0000
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi0/0 Desg FWD 20000 128.1 P2p
Gi1/3 Desg FWD 20000 128.8 P2p
Gi2/0 Desg FWD 20000 128.9 P2p
Gi2/1 Desg FWD 20000 128.10 P2p
Gi2/2 Desg FWD 20000 128.11 P2p
Gi2/3 Desg FWD 20000 128.12 P2p
Gi3/0 Desg FWD 20000 128.13 P2p
Gi3/1 Desg FWD 20000 128.14 P2p
Gi3/2 Desg FWD 20000 128.15 P2p
Gi3/3 Desg FWD 20000 128.16 P2p
Po13 Altn BLK 10000 128.65 P2p
Po14 Altn BLK 10000 128.66 P2p
Po12 Root FWD 10000 128.67 P2p
MST1
Spanning tree enabled protocol mstp
Root ID Priority 32769
Address 0c08.45ec.0000
Cost 10000
Port 67 (Port-channel12)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32769 (priority 32768 sys-id-ext 1)
Address 0cf6.d6fb.0000
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi0/0 Desg FWD 20000 128.1 P2p
Gi1/3 Desg FWD 20000 128.8 P2p
Gi2/0 Desg FWD 20000 128.9 P2p
Gi2/1 Desg FWD 20000 128.10 P2p
Gi2/2 Desg FWD 20000 128.11 P2p
Gi2/3 Desg FWD 20000 128.12 P2p
Gi3/0 Desg FWD 20000 128.13 P2p
Gi3/1 Desg FWD 20000 128.14 P2p
Gi3/2 Desg FWD 20000 128.15 P2p
Gi3/3 Desg FWD 20000 128.16 P2p
Po13 Altn BLK 10000 128.65 P2p
Po14 Altn BLK 10000 128.66 P2p
Po12 Root FWD 10000 128.67 P2pSW1: show span mst
SW1#sh span mst
##### MST0 vlans mapped: 301-4094
Bridge address 0cf6.d6fb.0000 priority 32768 (32768 sysid 0)
Root address 0c08.45ec.0000 priority 32768 (32768 sysid 0)
port Po12 path cost 0
Regional Root address 0c08.45ec.0000 priority 32768 (32768 sysid 0)
internal cost 10000 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
Interface Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Gi0/0 Desg FWD 20000 128.1 P2p
Gi1/3 Desg FWD 20000 128.8 P2p
Gi2/0 Desg FWD 20000 128.9 P2p
Gi2/1 Desg FWD 20000 128.10 P2p
Gi2/2 Desg FWD 20000 128.11 P2p
Gi2/3 Desg FWD 20000 128.12 P2p
Gi3/0 Desg FWD 20000 128.13 P2p
Gi3/1 Desg FWD 20000 128.14 P2p
Gi3/2 Desg FWD 20000 128.15 P2p
Gi3/3 Desg FWD 20000 128.16 P2p
Po13 Altn BLK 10000 128.65 P2p
Po14 Altn BLK 10000 128.66 P2p
Po12 Root FWD 10000 128.67 P2p
##### MST1 vlans mapped: 1-100
Bridge address 0cf6.d6fb.0000 priority 32769 (32768 sysid 1)
Root address 0c08.45ec.0000 priority 32769 (32768 sysid 1)
port Po12 cost 10000 rem hops 19
Interface Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Gi0/0 Desg FWD 20000 128.1 P2p
Gi1/3 Desg FWD 20000 128.8 P2p
Gi2/0 Desg FWD 20000 128.9 P2p
Gi2/1 Desg FWD 20000 128.10 P2p
Gi2/2 Desg FWD 20000 128.11 P2p
Gi2/3 Desg FWD 20000 128.12 P2p
Gi3/0 Desg FWD 20000 128.13 P2p
Gi3/1 Desg FWD 20000 128.14 P2p
Gi3/2 Desg FWD 20000 128.15 P2p
Gi3/3 Desg FWD 20000 128.16 P2p
Po13 Altn BLK 10000 128.65 P2p
Po14 Altn BLK 10000 128.66 P2p
Po12 Root FWD 10000 128.67 P2p SW2: show span mst
SW2#sh span mst
##### MST0 vlans mapped: 301-4094
Bridge address 0c08.45ec.0000 priority 32768 (32768 sysid 0)
Root this switch for the CIST
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
---------------- ---- --- --------- -------- --------------------------------
Gi0/0 Desg FWD 20000 128.1 P2p
Gi1/3 Desg FWD 20000 128.8 P2p
Gi2/0 Desg FWD 20000 128.9 P2p
Gi2/1 Desg FWD 20000 128.10 P2p
Gi2/2 Desg FWD 20000 128.11 P2p
Gi2/3 Desg FWD 20000 128.12 P2p
Gi3/0 Desg FWD 20000 128.13 P2p
Gi3/1 Desg FWD 20000 128.14 P2p
Gi3/2 Desg FWD 20000 128.15 P2p
Gi3/3 Desg FWD 20000 128.16 P2p
Po12 Desg FWD 10000 128.65 P2p
Po24 Desg FWD 10000 128.66 P2p
Po23 Desg FWD 10000 128.67 P2p
##### MST1 vlans mapped: 1-100
Bridge address 0c08.45ec.0000 priority 32769 (32768 sysid 1)
Root this switch for MST1
Interface Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Gi0/0 Desg FWD 20000 128.1 P2p
Gi1/3 Desg FWD 20000 128.8 P2p
Gi2/0 Desg FWD 20000 128.9 P2p
Gi2/1 Desg FWD 20000 128.10 P2p
Gi2/2 Desg FWD 20000 128.11 P2p
Gi2/3 Desg FWD 20000 128.12 P2p
Gi3/0 Desg FWD 20000 128.13 P2p
Gi3/1 Desg FWD 20000 128.14 P2p
Gi3/2 Desg FWD 20000 128.15 P2p
Gi3/3 Desg FWD 20000 128.16 P2p
Po12 Desg FWD 10000 128.65 P2p
Po24 Desg FWD 10000 128.66 P2p
Po23 Desg FWD 10000 128.67 P2p SW2: show span
SW2#sh span
MST0
Spanning tree enabled protocol mstp
Root ID Priority 32768
Address 0c08.45ec.0000
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32768 (priority 32768 sys-id-ext 0)
Address 0c08.45ec.0000
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi0/0 Desg FWD 20000 128.1 P2p
Gi1/3 Desg FWD 20000 128.8 P2p
Gi2/0 Desg FWD 20000 128.9 P2p
Gi2/1 Desg FWD 20000 128.10 P2p
Gi2/2 Desg FWD 20000 128.11 P2p
Gi2/3 Desg FWD 20000 128.12 P2p
Gi3/0 Desg FWD 20000 128.13 P2p
Gi3/1 Desg FWD 20000 128.14 P2p
Gi3/2 Desg FWD 20000 128.15 P2p
Gi3/3 Desg FWD 20000 128.16 P2p
Po12 Desg FWD 10000 128.65 P2p
Po24 Desg FWD 10000 128.66 P2p
Po23 Desg FWD 10000 128.67 P2p
MST1
Spanning tree enabled protocol mstp
Root ID Priority 32769
Address 0c08.45ec.0000
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 32769 (priority 32768 sys-id-ext 1)
Address 0c08.45ec.0000
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi0/0 Desg FWD 20000 128.1 P2p
Gi1/3 Desg FWD 20000 128.8 P2p
Gi2/0 Desg FWD 20000 128.9 P2p
Gi2/1 Desg FWD 20000 128.10 P2p
Gi2/2 Desg FWD 20000 128.11 P2p
Gi2/3 Desg FWD 20000 128.12 P2p
Gi3/0 Desg FWD 20000 128.13 P2p
Gi3/1 Desg FWD 20000 128.14 P2p
Gi3/2 Desg FWD 20000 128.15 P2p
Gi3/3 Desg FWD 20000 128.16 P2p
Po12 Desg FWD 10000 128.65 P2p
Po24 Desg FWD 10000 128.66 P2p
Po23 Desg FWD 10000 128.67 P2p 参考
multiple spanning tree port roles !!