3Com 8807 Configuration Manual page 146

146 C 17: MSTP R
HAPTER
Configuring the mCheck
Variable of a Port
n
Configuring the
Function of Clearing
Dynamic ARP Entries
n
-
EGION CONFIGURATION
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 measure to perform mCheck operation on a port.
Configuration in system view
Perform the following configuration in system view.
Table 128 Configure the mCheck variable of a port
Operation
Perform mCheck operation on a port
By default, MSTP runs in MSTP mode, which is compatible with RSTP and STP (This
mode can recognize MSTP BPDU, STP config BPDU and RSTP config BPDU).
However, the STP switch can only recognize config BPDU (STP BPDU) sent by the
STP and RSTP bridges. After the switch running STP-compatible mode switches
back to MSTP mode, it will not send MSTP BPDU if you do not execute the stp
mcheck command. Therefore, the connected device still sends config BPDU (STP
BPDU) to it, causing the same configuration exists in different regions and other
problems. Remember to perform stp interface mcheck after modifying stp mode.
Configuration in Ethernet port view
Perform the following configuration in Ethernet port view.
Table 129 Configure the mCheck variable of a port
Operation
Perform mCheck operation on a port
You can configure mCheck variable on a port with either of the earlier-mentioned
measures. 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.
Perform the following configuration in Ethernet port view or system view.
Table 130 Configure the function of clearing dynamic ARP entries
Operation
Enable the function of clearing dynamic ARP
entries on the switch or on a port
Disable the function of clearing dynamic ARP
entries on the switch or on a port
Enable the root protection function (system
view)
If you enable the function of clearing dynamic ARP entries in system view, the
function takes effect on all ports of the system. If you enable the function of
Command
stp interface interface-list mcheck
Command
stp mcheck
Command
stp reset-arp enable
stp reset-arp disable
stp interface interface-list root-protection