Rstp Mode; Mstp Mode - Zte ZXR10 5900 Series User Manual

ZXR10 5900/5200 Series User Manual (Ethernet Switching Volume)
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RSTP Mode

Rapid Spanning Tree Protocol (RSTP) provides a faster aggregation
speed than STP (that is, SSTP mode). When the network topology
changes, the state of the redundant switch port can make a fast
shift (Discard > Forword) in the case of point-to-point connection.

MSTP Mode

Two concepts are added to Multiple Spanning Tree Protocol
(MSTP): instance and
regarded as a special case of the MSTP mode. There only exists
one instance, that is, instance 0. The MSTP mode also provides
fast aggregation and load balance under the VLAN environment.
In SSTP and RSTP modes, there is no concept of VLAN. There ex-
ists one port state, that is, forwarding state. The state of a port
in different VLANs is the same. In MSTP mode there can exist
multiple spanning-tree instances. Forwarding states of a port un-
der different VLANs can be different. Many independent sub-tree
instances can be formed inside the MST area to implement load
balance.
The following are the basic concepts of MSTP:
1. MST Config ID
It is a forwarding scheme for frames with different VIDs. That
is in an MST area all the bridges are forwarded to specific span-
ning trees (CIST or an MST instance) according to the VID in
the frame.
MST Config ID is composed of the following parts:
Configuration name: a character string of 32 bytes.
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Version: non-negative integer of two bytes.
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Configuration summary: signature based on the MST Con-
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fig Table and after
bytes.
MST Config Table is composed of 4,096 continuous dual-types.
The First and last dual-bytes are 0. Other dual-byte represents
a binary number. Second dual-byte stands for the MSTID to
which VID 1 corresponds. Third dual-byte stands for the MSTID
to which VID 2 corresponds and the second last dual-byte rep-
resents the MSTID to which VID 4094 corresponds. Configura-
tion summary is obtained by calculating the MST Config Table
and a fixed KEY value through the
resolution, it can know a certain VID belongs to which MST in-
stance or CIST.
2. MST Area
Each MST area is composed of one or several connected bridges
with the same MST Config ID. These bridges use the same in-
stances. This area also includes the LAN designating the bridge
in the CIST instance.
VLAN mapping. SSTP/RSTP mode can be
MD5 processing, with a length of 16
HMAC-MD5 algorithm. By