Stpd Modes - Extreme Networks ExtremeWare XOS Guide Manual

Spanning Tree Protocol (STP)
Specifying the Carrier VLAN
The following example:
• Creates and enables an STPD named s8
• Creates a VLAN named v5
• Assigns VLAN v5 to STPD s8
• Creates the same tag ID for the VLAN and the STPD (the carrier VLAN's StpdID must be identical
to the VLANid of one of the member VLANs)
create vlan v5
configure vlan v5 tag 100
configure vlan v5 add ports 1:1-1:20 tagged
create stpd s8
configure stpd s8 add vlan v5 ports all emistp
configure stpd s8 tag 100
enable stpd s8
Notice how the tag number for the VLAN v5 and the STPD s8 is identical (the tag is 100). By using
identical tags, you have selected the carrier VLAN. The carrier VLAN's StpdID is identical to the
VLANid of the member VLAN.

STPD Modes

An STPD has two modes of operation:
• 802.1d mode
Use this mode for backward compatibility with previous STP versions and for compatibility with
third-party switches using IEEE standard 802.1d. When configured in this mode, all rapid
configuration mechanisms are disabled.
• 802.1w mode
Use this mode for compatibility with Rapid Spanning Tree (RSTP). When configured in this mode,
all rapid configuration mechanisms are enabled. The benefit of this mode is available on
point-to-point links only and when the peer is likewise configured in 802.1w mode. If you do not
select point-to-point links and the peer is not configured for 802.1w mode, the STPD fails back to
802.1d mode.
RSTP is enabled or disabled on a per STPD basis only. You do not enable RSTP on a per port basis.
For more information about RSTP and RSTP features, see "Rapid Spanning Tree Protocol" on
page 148.
By default, the:
• STPD operates in 802.1d mode
• Default device configuration contains a single STPD called s0
• Default VLAN is a member of STPD s0 with autobind enabled
To configure the mode of operation of an STPD, use the following command:
configure stpd <stpd_name> mode [dot1d | dot1w]
All STP parameters default to the IEEE 802.1d values, as appropriate.
138 ExtremeWare XOS 10.1 Concepts Guide