Mstp; Why Mstp - HP A6600 Configuration Manual

point-to-point link, it can enter the forwarding state immediately after the device undergoes handshake
with the downstream device and gets a response.

MSTP

Why MSTP

Limitations of STP and RSTP
STP does not support rapid state transition of ports. A newly elected root port or designated port must
wait twice the forward delay time before transiting to the forwarding state, even if it is a port on a
point-to-point link or an edge port.
Although RSTP supports rapid network convergence, it has the same drawback as STP does: All bridges
within a LAN share the same spanning tree, so redundant links cannot be blocked based on VLAN, and
the packets of all VLANs are forwarded along the same spanning tree.
Features of MSTP
Developed based on IEEE 802.1s, MSTP overcomes the shortcomings of STP and RSTP. In addition to the
support for rapid network convergence, it allows data flows of different VLANs to be forwarded along
separate paths, thus providing a better load sharing mechanism for redundant links. For more information
about VLANs, see the chapter "VLAN configuration."
MSTP features the following:
MSTP supports mapping VLANs to spanning tree instances by means of a VLAN-to-instance
•
mapping table. MSTP can reduce communication overheads and resource usage by mapping
multiple VLANs to one instance.
MSTP divides a switched network into multiple regions, each containing multiple spanning trees that
•
are independent of one another.
MSTP prunes a loop network into a loop-free tree, thus avoiding proliferation and endless cycling of
•
packets in a loop network. In addition, it provides multiple redundant paths for data forwarding,
thus supporting load balancing of VLAN data.
• MSTP is compatible with STP and RSTP.
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