Extreme Networks ExtremeWare XOS 11.3, Manual

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Spanning Tree Domains
ExtremeWare XOS 11.3 Concepts Guide
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Assigns VLAN v5 to STPD s8 .
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Creates the same tag ID for the VLAN and the STPD (the carrier VLAN’s VLANid must be identical
to the STPDs StpdID).
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 VLANid is identical to the
STPD’s StpdID.
STPD Modes
An STPD has two modes of operation:
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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.
You enable or disable RSTP 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 436 .
By default, the:
●
STPD operates in 802.1D mode.
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Default device configuration contains a single STPD called s0 .
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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.
Encapsulation Modes
You can configure ports within an STPD to accept specific BPDU encapsulations. This STP port
encapsulation is separate from the STP mode of operation. For example, you can configure a port to
accept the PVST+ BPDU encapsulation while running in 802.1D mode.