Rstp debug commands – Brocade FastIron SX, FCX, and ICX Diagnostic Reference User Manual

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Brocade FastIron SX, FCX, and ICX Diagnostic Reference

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RSTP debug commands

If the configuration of VLAN 2 on the Brocade FCX is disabled, the output similar to the following is
displayed.

Brocade# no debug span config vlan 2

STP : Disabling Packets Debugging for VLAN 2

debug span timers

Syntax: [no] debug span timers vlan decimal

This command displays information about the specific STP timer events. The decimal variable
refers to the number of the VLAN.

If the STP timer event on VLAN 2 of the Brocade FastIron device is enabled, the output similar to
the following is displayed.

Brocade# debug span timers vlan 2

STP Enabling Timer Debugging for VLAN 2

Sample output:

STP: Timer Alert - Forward Delay Timer expired On port 1/1/6(5) , VLAN 2

STP: Timer Alert - Forward Delay Timer expired On port 1/1/1(0) , VLAN 2

STP: Timer Alert - Forward Delay Timer expired On port 1/1/6(5) , VLAN 2

STP: Timer Alert - Message Age Timer expired On port 1/1/1(0) , VLAN 2

STP: Timer Alert - Message Age Timer expired On port 1/1/2(1) , VLAN 2

STP: Timer Alert - Forward Delay Timer expired On port 1/1/2(1) , VLAN 2

If the STP timer event on VLAN 2 of the Brocade FastIron device is disabled, the output similar to
the following is displayed.

Brocade# no debug span timers vlan 2

STP Disabling Timer Debugging for VLAN 2

RSTP debug commands

RSTP provides rapid traffic reconvergence for point-to-point links within a few milliseconds (less
than 500 milliseconds) following the failure of a bridge or bridge port. This reconvergence occurs
more rapidly than that provided by STP because convergence in RSTP bridges is based on the
explicit handshakes between designated ports and their connected root ports rather than on timer
values. The debug 802.1w command displays some information about RSTP.

NOTE

For RSTP debug commands, enter 4094 if STP is enabled. Enter the VLAN ID for Multiple Spanning
Tree Protocol (MSTP). The CLI alerts the user if the VLAN ID does not exist.

debug 802.1w all_802_1w_events

Syntax: [no] debug 802.1w all_802_1w_events vlan decimal

This command debugs all the RSTP transactions, timers, and packets on a specific VLAN. The
decimal variable refers to the number of the VLAN.

If the events are enabled, the output similar to the following is displayed.

Brocade# debug 802.1w all_802_1w_events vlan 2

RSTP Enabling All events Debugging for VLAN 2