Modify Interface Parameters - Dell Force10 C150 Configuration Manual

Modify Interface Parameters

You can adjust two interface parameters to increase or decrease the probability that a port becomes a
forwarding port:
• Port cost is a value that is based on the interface type. The greater the port cost, the less likely the port
will be selected to be a forwarding port.
• Port priority influences the likelihood that a port will be selected to be a forwarding port in case that
several ports have the same port cost.
Table 29-2
Table 29-2. MSTP Default Port Cost Values
Port Cost
100-Mb/s Ethernet interfaces
1-Gigabit Ethernet interfaces
10-Gigabit Ethernet interfaces
Port Channel with 100 Mb/s Ethernet interfaces
Port Channel with 1-Gigabit Ethernet interfaces
Port Channel with 10-Gigabit Ethernet interfaces
To change the port cost or priority of an interface:
Task
Change the port cost of an interface.
Range: 0 to 200000
Default: see Table
Change the port priority of an interface.
Range: 0 to 240, in increments of 16
Default: 128
View the current values for these interface parameters using the command
mode. See
650 | Multiple Spanning Tree Protocol
lists the default values for port cost by interface.
29-2.
Figure 29-8.
Default Value
200000
20000
2000
180000
18000
1800
Command Syntax
spanning-tree msti number cost cost
spanning-tree msti number priority priority
Command Mode
INTERFACE
INTERFACE
show config
from INTERFACE