iPECS ES-3052GP - Table 11: Recommended STA Path Cost Range; Table 12: Default STA Path Costs

C HAPTER 8 | Spanning Tree Algorithm
Configuring Interface Settings for STA
– 218 –
ES-3052 Series
port priority. (Range: 0 for auto-configuration, 1-65535 for the short
path cost method
4
, 1-200,000,000 for the long path cost method)
By default, the system automatically detects the speed and duplex
mode used on each port, and configures the path cost according to the
values shown below. Path cost “0” is used to indicate auto-configuration
mode. When the short path cost method is selected and the default
path cost recommended by the IEEE 8021w standard exceeds 65,535,
the default is set to 65,535.
◆ Admin Link Type – The link type attached to this interface.
■
Point-to-Point – A connection to exactly one other bridge.
■
Shared – A connection to two or more bridges.
■
Auto – The switch automatically determines if the interface is
attached to a point-to-point link or to shared media. (This is the
default setting.)
◆ Root Guard – STA allows a bridge with a lower bridge identifier (or
same identifier and lower MAC address) to take over as the root bridge
at any time. Root Guard can be used to ensure that the root bridge is
not formed at a suboptimal location. Root Guard should be enabled on
any designated port connected to low-speed bridges which could
potentially overload a slower link by taking over as the root port and
forming a new spanning tree topology. It could also
be used to form a
border around part of the network where the root bridge is allowed.
(Default: Disabled)
◆ Admin Edge Port – Refer to “Admin Edge Status for all ports” at the
beginning of this section.
4. Refer to "Configuring Global Settings for STA" on page 209 for information on setting the
path cost method.
Table 11: Recommended STA Path Cost Range
Port Type IEEE 802.1D-1998 IEEE 802.1w-2001
Ethernet 50-600 200,000-20,000,000
Fast Ethernet 10-60 20,000-2,000,000
Gigabit Ethernet 3-10 2,000-200,000
Table 12: Default STA Path Costs
Port Type Short Path Cost
(IEEE 802.1D-1998)
Long Path Cost
(802.1D-2004)
Ethernet 65,535 1,000,000
Fast Ethernet 65,535 100,000
Gigabit Ethernet 10,000 10,000