Brocade FastIron SX, FCX, and ICX Diagnostic Reference - Manual (Page 30)

18 Brocade FastIron SX, FCX, and ICX Diagnostic Reference
53-1003076-02
MSTP debug commands
3
debug 802.1w transitions
Syntax: [no] debug 802.1w transitions vlan decimal
This command debugs the RSTP state machine transitions. The decimal variable refers to the
number of the VLAN.
If the 802.1w transtitions are enabled, an output similar to the following is displayed.
Brocade# debug 802.1w transitions vlan 2
RSTP Enabling Events Debugging for VLAN 2
Brocade# RSTP: PRT =>no valid transition found ,no error, port 1/1/1(0) VLAN 2
RSTP: PTX entering the Periodic state , port 1/1/2(1) VLAN 2
RSTP: PTX =>ROLE is ALTERNATE or BACKUP , port 1/1/2(1), VLAN 2
RSTP: PTX entering the Periodic state , port 1/1/9(8) VLAN 2
RSTP: PRT =>no valid transition found ,no error, port 1/1/1(0) VLAN 2
RSTP: PTX entering the Periodic state , port 1/1/2(1) VLAN 2
RSTP: PTX =>ROLE is ALTERNATE or BACKUP , port 1/1/2(1), VLAN 2
RSTP: PTX entering the Periodic state , port 1/1/9(8) VLAN 2
RSTP: PRT =>no valid transition found ,no error, port 1/1/1(0) VLAN 2
RSTP: PTX entering the Periodic state , port 1/1/2(1) VLAN 2
RSTP: PTX =>ROLE is ALTERNATE or BACKUP , port 1/1/2(1), VLAN 2
RSTP: PTX entering the Periodic state , port 1/1/9(8) VLAN 2
If the 802.1w transtitions are disabled, the output similar to the following is displayed.
Brocade# no debug 802.1w transitions vlan 2
RSTP Disabling Events Debugging for VLAN 2
MSTP debug commands
With Multiple Spanning Tree Protocol (MSTP), the entire network runs a common instance of RSTP.
Within the common instance, one or more VLANs can be individually configured into distinct
regions. The entire network runs the Common Spanning Tree (CST) instance and the regions run a
local instance, or Internal Spanning Tree (IST). Because the CST treats each IST as a single bridge,
ports are blocked to prevent loops that might occur within an IST and also throughout the CST. In
addition, MSTP can coexist with individual devices running STP or RSTP in the Common and
Internal Spanning Tree instance (CIST). With the exception of the provisions for multiple instances,
MSTP operates exactly like RSTP.
The following MSTP debug commands are used for debugging information.
debug mstp bpdu
Syntax: [no] debug mstp bpdu
This command records and displays information in conjunction with the debug mstp enable and
debug mstp events commands. When the debug mstp bpdu command is enabled, it monitors
MSTP BPDUs.
If this command is enabled, an output similar to the following is displayed.
Brocade# debug mstp bpdu
MSTP Bpdu debugging ON
Brocade# debug mstp enable
Brocade# MSTP[0xeb217]: PRX RECEIVE->RECEIVE - Port 1/1/1