Owner's Manual

558 | Chapter 18. STP
NETGEAR 8800 User Manual
• MSTP Port Roles on page 565
• MSTP Port States on page 565
• MSTP Link Types on page 565
• MSTP Edge Safeguard on page 565
• MSTP Timers on page 566
• MSTP Hop Counts on page 566
• Configuring MSTP on the Switch on page 566
MSTP Regions
An MSTP network consists of either individual MSTP regions connected to the rest of the
network with 802.1D and 802.1w bridges or as individual MSTP regions connected to each
other. An MSTP region defines the logical boundary of the network. With MSTP, you can
divide a large network into smaller areas similar to an OSPF area or a BGP Autonomous
System, which contain a group of switches under a single administration. Each MSTP region
has a unique identifier, is bound together by one CIST that spans the entire network. A bridge
participates in only one MSTP region at a time.
An MSTP region can hide its internal STPDs and present itself as a virtual 802.1w bridge to
other interconnected regions or 802.1w bridges because the port roles are encoded in
802.1w and MSTP BPDUs.
By default, the switch uses the MAC address of the switch to generate an MSTP region.
Since each MAC address is unique, every switch is in its own region by default. For multiple
switches to be part of an MSTP region, you must configure each switch in the region with the
same MSTP region identifiers. See
Configuring MSTP Region Identifiers on page 559 for
information.
In Figure 50, all bridges inside MSTP regions 1 and 2 are MSTP bridges; bridges outside of
the regions are either 802.1D or 802.1w bridges.