Extreme Networks ExtremeWare XOS 10.1, Manual

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STP Rules and Restrictions
ExtremeWare XOS 10.1 Concepts Guide 159
STP Rules and Restrictions
This section summarizes the rules and restrictions for configuring STP.
•
The carrier VLAN must span all of the ports of the STPD.
• The StpdID must be the VLANid of one of its member VLANs, and that VLAN cannot be
partitioned.
• A default VLAN can not be partitioned. If a VLAN traverses multiple STP domains, the VLAN must
be tagged.
• An STPD can carry, at most, one VLAN running in PVST+ mode, and its StpdID must be identical
with that VLANid. In addition, the PVST+ VLAN cannot be partitioned.
•
The default VLAN of a PVST+ port must be identical with the native VLAN on the PVST+ device
connected to that port.
• If a port supports 802.1d-STPD, then the port must be configured with a default VLAN. If not, the
BPDUs for that STPD are not flooded when the STPD is disabled.
• If an STPD contains both PVST+ and non-PVST+ ports, it must be enabled. If it is disabled, the
BPDUs are flooded in the format of the incoming STP port, which may be incompatible with those of
the connected devices.
• 802.1d ports must be untagged; EMISTP/PVST+ ports must be tagged.
• An STPD with multiple VLANs must contain only VLANs that belong to the same virtual router
instance.
Configuring STP on the Switch
To configure basic STP:
1
Create one or more STP domains using the following command:
create stpd <stpd_name>
NOTE
STPD, VLAN, and QoS profile names must all be unique. For example, a name used to identify a
VLAN cannot be used when you create an STPD or a QoS profile.
2 Add one or more VLANs to the STPD using the following command:
configure stpd <stpd_name> add vlan <vlan_name> ports [all | <port_list>] {[dot1d
| emistp | pvst-plus]}
3 Define the carrier VLAN using the following command:
configure stpd <stpd_name> tag <stpd_tag>
NOTE
The carrier VLAN’s StpdID must be identical to the VLANid of one of the member VLANs.
4 Enable STP for one or more STP domains using the following command:
enable stpd {<stpd_name>}