Configuration Procedure; Configuring Path Costs Of Ports; Specifying A Standard For The Device To Use When It Calculates The Default Path Cost - HP 6125XLG Configuration Manual

Configuration procedure

To configure a port as an edge port:
Step
1. Enter system view.
2. Enter Layer 2 Ethernet or
aggregate interface view.
3. Configure the current ports as
edge ports.

Configuring path costs of ports

Path cost is a parameter related to the rate of a port. On a spanning tree device, a port can have different
path costs in different MSTIs. Setting appropriate path costs allows VLAN traffic flows to be forwarded
along different physical links, achieving VLAN-based load balancing.
You can have the device automatically calculate the default path cost, or you can configure the path cost
for ports.
Specifying a standard for the device to use when it calculates
the default path cost
CAUTION:
If you change the standard that the device uses to calculate the default path costs, you restore the path
costs to the default.
You can specify a standard for the device to use in automatic calculation for the default path cost. The
device supports the following standards:
• dot1d-1998—The device calculates the default path cost for ports based on IEEE 802.1d- 1 998.
dot1t—The device calculates the default path cost for ports based on IEEE 802.1t.
•
legacy—The device calculates the default path cost for ports based on a private standard.
•
When you specify a standard for the device to use when it calculates the default path cost, follow these
guidelines:
When it calculates the path cost for an aggregate interface, IEEE 802.1t takes into account the
•
number of Selected ports in its aggregation group. However, IEEE 802.1d- 1 998 does not take into
account the number of Selected ports. The calculation formula of IEEE 802.1t is: Path cost =
200,000,000/link speed (in 100 kbps), where link speed is the sum of the link speed values of the
Selected ports in the aggregation group.
• IEEE 802.1d- 1 998 or the private standard always assigns the smallest possible value to a single port
or aggregate interface with a speed exceeding 10 Gbps. The forwarding path selected based on
this criterion might not be the best one. To solve this problem, perform one of the following actions:
Use dot1t as the standard for default path cost calculation.
Manually set the path cost for the port (see
Command
system-view
interface interface-type interface-number
stp edged-port
"Configuring path costs of
99
Remarks
N/A
N/A
By default, all ports are
non-edge ports.
ports").