3Com Switch 8807, Configuration Manual

Page: 132 / 883

132 C
HAPTER
17: MSTP R
EGION
-
CONFIGURATION
designated port begin to send data again. That is, the root port and designated
port should undergo a transitional state for a period of Forward Delay before they
enter the forwarding state.
And thus, the packets of a VLAN will be forwarded along the following path: in
the MST region, the packets will be forwarded along the corresponding MSTI;
among the regions, the packets will be forwarded along the CST.
MSTP Implementation
on the Switch
MSTP is compatible with STP and RSTP. The MSTP switch can recognize both the
STP and RSTP packets and calculate the spanning tree with them. Besides the basic
MSTP functions, 3Com Ethernet Switch Series also provide some features easy to
manage from users’ point of view. These features include root bridge hold,
secondary root bridge, ROOT protection, BPDU protection, loop protection, hot
swapping of the interface modules, master/slave switchover, and so on. Note that
the spanning tree needs to be calculated again when a master/slave switchover
occurs.
Configuring MSTP
MSTP configuration includes:
■
“Configuring the MST Region for a Switch”
■
“Specifying the Switch as a Primary or a Secondary Root bridge”
■
“Configuring the MSTP Running Mode”
■
“Configuring the Bridge Priority for a Switch”
■
“Configuring the Max Hops in an MST Region”
■
“Configuring the Switching Network Diameter”
■
“Configuring the Time Parameters of a Switch”
■
“Setting the Timeout Factor of a Specific Bridge”
■
“Configuring the Max Transmission Speed on a Port”
■
“Configuring a Port as an Edge Port or Non-edge Port”
■
“Configuring the Path Cost of a Port”
■
“Configuring the Priority of a Port”
■
“Configuring the Port (Not) to Connect with the Point-to-Point Link”
■
“Configuring the mCheck Variable of a Port”
■
“Configuring the Switch Protection Function”
■
“Enabling/Disabling MSTP on the Device”
■
“Enabling/Disabling MSTP on a Port”
■
“Configuring the mapping relationship between a VLAN list and a Spanning
Tree Instance”
Only after MSTP is enabled on the device will other configurations take effect.
Before enabling MSTP, you can configure the related parameters of the device and
Ethernet ports, which will take effect upon enabling MSTP and stay effective even
after resetting MSTP. The
check region-configuration command can display the
region parameters that have not yet taken effect. The display
current-configuration command shows the parameters configured before MSTP
is enabled. For those configured after MSTP is enabled, you can use the related