Dell Force10 S4810P Configuration Manual page 707

Figure 32-14. Displaying BPDUs and Events
FTOS#debug spanning-tree mstp
1w1d17h : MSTP: Sending BPDU on Gi 1/31 :
ProtId: 0, Ver: 3, Bpdu Type: MSTP, Flags 0x68
CIST Root Bridge Id: 32768:0001.e806.953e, Ext Path Cost: 20000
Regional Bridge Id: 32768:0001.e809.c24a, CIST Port Id: 128:384
Msg Age: 2, Max Age: 20, Hello: 2, Fwd Delay: 15, Ver1 Len: 0, Ver3 Len: 96
Name: my-mstp-region, Rev: 0, Int Root Path Cost: 20000
Rem Hops: 19, Bridge Id: 32768:0001.e80d.b6d6
E1200#1w1d17h : INST 1: Flags: 0x28, Reg Root: 32768:0001.e809.c24a, Int Root Co
Brg/Port Prio: 32768/128, Rem Hops: 19
INST 2: Flags: 0x68, Reg Root: 4096:0001.e809.c24a, Int Root Cost: 20000
Brg/Port Prio: 32768/128, Rem Hops: 19
[output omitted]
FTOS#debug spanning-tree mstp
1w1d17h : MSTP: TC flag set in the incoming BPDU on port Gi 1/31 for instance 0
1w1d17h : MSTP: TC flag set in the incoming BPDU on port Gi 1/31 for instance 0
1w1d17h : MSTP: TC flag set in the incoming BPDU on port Gi 1/31 for instance 0
Examine your individual routers to ensure all the necessary parameters match.
1. Region Name
2. Region Version
3. VLAN to Instance mapping
The
show spanning-tree mst
overall MSTP configuration on the router, use the
Privilege mode (output sample shown in
Use the
debug spanning-tree mstp bpdu
connected and communicating as desired (output sample shown in
Key items to look for in the debug report:
• MSTP flags indicate communication received from the same region.
• In Figure 32-16, the output shows that the MSTP routers are located in the same region.
• Does the debug log indicate that packets are coming from a "Different Region"
so, one of the key parameters is not matching.
• MSTP Region Name and Revision
• The configured name and revisions must be identical among all the routers.
• Is the Region name blank? That may mean that a name was configured on one router and but was
not configured or was configured differently on another router (spelling and capitalization counts).
• MSTP Instances.
• Use the show commands to verify the VLAN to MSTP Instance mapping.
• Are there "extra" MSTP Instances in the Sending or Received logs? That may mean that an
additional MSTP Instance was configured on one router but not the others.
bpdu
events
commands will show various portions of the MSTP configuration. To view the
show running-configuration spanning-tree mstp
Figure 32-15).
command to monitor and verify that the MSTP configuration is
Figure 32-16).
(Figure
Multiple Spanning Tree Protocol (MSTP) | 707
in the EXEC
32-17)? If