3Com 7700 Configuration Manual page 243

Configuring the mCheck
Variable of a Port
Configuring the Switch
Security Function
For the ports connected with the point-to-point link, upon some port role
conditions met, they can transit to forwarding state fast through transmitting
synchronization packet, thereby reducing the unnecessary forwarding delay. If the
parameter is configured as auto mode, MSTP will automatically detect if the
current Ethernet port is connected with the point-to-point link.
Note: For a link aggregation, only the master port can be configured to connect
with the point-to-point link. If a port in auto-negotiation mode operates in
full-duplex mode upon negotiation, it can be configured to connect with the
point-to-point link.
This configuration takes effect on the CIST and all the MSTIs. The settings of a port
determine whether the point-to-point link will be applied to all the STIs to which
the port belongs. Note that a temporary loop may be redistributed if you configure
a port not physically connected with the point-to-point link as connected to such a
link by force.
By default, the parameter is configured as auto.
The port of an MSTP switch operates in either STP-compatible or MSTP mode.
Suppose a port of an MSTP switch on a switching network is connected to an STP
switch, the port will automatically transit to operate in STP-compatible mode.
However, the port stays in STP-compatible mode and cannot automatically transit
back to MSTP mode when the STP switch is removed. In this case, you can
perform mCheck operation to transit the port to MSTP mode by force.
You can use the following measures to perform mCheck operation on a port.
Configuring in system view
Perform the following configuration in system view.
Configure the mCheck Variable of a Port
Table 37
Operation
Perform mCheck operation on a port.
Configuring in Ethernet port view
Perform the following configuration in Ethernet port view.
Configure the mCheck Variable of a Port
Table 38
Operation
Perform mCheck operation on a port.
For more about the commands, see the Switch 7700 Command Reference Guide.
Note that the command can be used only if the switch runs MSTP. The command
does not make any sense when the switch runs in STP-compatible mode.
An MSTP switch provides BPDU protection and Root protection functions.
For an access device, the access port is generally directly connected to the user
terminal or a file server, and the access port is set to edge port to implement fast
Configuring MSTP
Command
stp interface interface-list mcheck
Command
stp mcheck
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