Brocade Multi-Service IronWare Switching Configuration Guide (Supporting R05.6.00) - Manual (Page 399)

Multi-Service IronWare Switching Configuration Guide 369
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MSTP support for PBB
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Interoperability between MSTP and Single STP or Single RSTP
• MSTP can interoperate with SSTP or a RSTP. However it is recommended to assign all VLANs to
CIST (MSTP instance 0) while operating in a SSTP or a RSTP domain since only CIST
participates in the convergence with SSTP or a RSTP.
• If the STP or RSTP is enabled on a native VLAN or on an untagged VLAN (or if SSTP or a single
RSTP is configured), it sends out untagged BPDUs and can interoperate with MSTP which
consumes these untagged BPDUs and converges accordingly. These untagged BPDUs can also
converge with SSTP or RSTP configured on the receiving side resulting in the MSTP not being
configured.
• If STP is enabled on a native VLAN or an untagged VLAN or if SSTP or RSTP is configured, it will
converge with STP enabled on native or an untagged VLAN if configured, or with RSTP enabled
on native or untagged VLAN if configured, or otherwise with SSTP/Single RSTP/MSTP if
configured on the receiving side.
MSTP support for PBB
When applied to a PBB environment, this feature will ensure a loop free topology.
Scalability
• A maximum of 16 MSTP Instances are allowed per MSTP region.
• A maximum of 10 MSTP regions are allowed.
• A maximum of 40 MSTP Instances are allowed.
Limitations
The following restrictions apply when are using MSTP with PBB
• Dual homing of an AS configured with SVLANs in an Edge RSTP and Dual homing of a CS
configured with regular VLANs in a Core MSTP is supported, but Dual homing of both AS and
CS in an Edge and Core MSTP together is not supported.
• Each switch in a single MSTP region needs to be configured with unique name, but must use
the same region name and revision number.
• For each MSTP region, the configured VLANs for an MSTP instance need to be of the same
type, for example, either VLANs (that is, not VPLS VLANs), SVLANs, or CVLANs. This means
VLANS, SVLANs, and CVLANs cannot be configured to co-exist within the same region.
• In the case of an VLAN, SVLAN, or CVLAN, the same VLAN ID cannot be configured as a part of
two different MSTP instances within an MSTP region.
• MSTP configuration for VPLS VLANs with ISIDs is not supported.
• An interface can be a part of only one region when multiple regions are configured on a switch.
• Legacy and multi region MSTP configuration is not allowed at the same time on a switch.
• VPLS instances having two different VLANs is not supported.
• There is no MIB support for PBB MSTP.