Brocade Multi-Service IronWare Switching Configuration Guide (Supporting R05.6.00) - Manual (Page 382)

352 Multi-Service IronWare Switching Configuration Guide
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PVST or PVST+ compatibility
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Enabling PVST+ support
PVST+ support is automatically enabled when the port receives a PVST BPDU. You can manually
enable the support at any time or disable the support if desired.
If you want a tagged port to also support IEEE 802.1Q BPDUs, you need to enable the dual-mode
feature on the port. The dual-mode feature is disabled by default and must be enabled manually.
A port that is in PVST+ compatibility mode due to auto-detection reverts to the default MSTP mode
when one of the following events occurs:
• The link is disconnected or broken
• The link is administratively disabled
• The link is disabled by interaction with the link-keepalive protocol
This allows a port that was originally interoperating with PVST+ to revert to multiple spanning tree
when connected to a Brocade device.
Enabling PVST+ support manually
To immediately enable PVST+ support on a port, enter commands such as the following.
Brocade(config)# interface ethernet 1/1
Brocade(config-if-e1000-1/1)# pvst-mode
Syntax: [no] pvst-mode
NOTE
If you disable PVST+ support, the software still automatically enables PVST+ support if the port
receives a BPDU with PVST+ format.
Displaying PVST+ support information
To display PVST+ information for ports on a Brocade device, enter the following command at any
level of the CLI.
Syntax: show span pvst-mode
This command displays the following information.
Brocade(config)# show span pvst-mode
PVST+ Enabled on:
Port Method
1/1 Set by configuration
1/2 Set by configuration
2/10 Set by auto-detect
3/12 Set by configuration
4/24 Set by auto-detect