Configuring Port Mode - Alcatel-Lucent OmniSwitch 9900 Series Network Configuration Manual

Configuring Spanning Tree Parameters
To change the port path cost value for the flat mode instance regardless of which mode (per-VLAN or flat)
is active for the switch, use the
configures a 32-bit path cost value for port 1/24 for the flat mode instance to 20,000 (the port speed is 1
GB, 20,000 is the recommended value):
-> spantree cist port 1/24 path-cost 20000
The port path cost value is also configurable for a Multiple Spanning Tree Instance (MSTI). To configure
this value for an MSTI, use the
instance number. For example, the following command configures the path cost value for port 1/12 for
MSTI 10 to 19:
-> spantree msti 10 port 1/12 path-cost 19
Note that configuring the port path cost value for a MSTI is allowed in both modes (per-VLAN and flat)
only when the Spanning Tree protocol is set to MSTP.
Path Cost for Link Aggregate Ports
Physical ports that belong to a link aggregate do not participate in the Spanning Tree Algorithm. Instead,
the algorithm is applied to the aggregate logical link (virtual port) that represents a collection of physical
ports. Spanning Tree is automatically enabled on the aggregate logical link and the path cost value is set to
the default value using the tables above.
To change the path cost value for a link aggregate, use the spantree cist path cost, spantree msti path
cost, or spantree vlan path cost command with the linkagg parameter and a link aggregate control (ID)
number. For example, the following command sets the path cost for link aggregate 10 associated with
VLAN 755 to 19:
-> spantree vlan 755 linkagg 10 path-cost 19
For more information about configuring an aggregate of ports, see
Aggregation," and Chapter 9, "Configuring Dynamic Link Aggregation."

Configuring Port Mode

There are two port modes supported: manual and dynamic. Manual mode indicates that the port was set by
the user to a forwarding or blocking state. The port operates in the state selected until the state is manually
changed again or the port mode is changed to dynamic. Ports operating in a manual mode state do not
participate in the Spanning Tree Algorithm. Dynamic mode indicates that the active Spanning Tree
Algorithm determines port state.
Spanning Tree is automatically enabled on the port and the port operates in the default mode. If the switch
is running in the per-VLAN Spanning Tree mode, then the port mode applies to the specified VLAN
instance associated with the port. If the switch is running in the flat Spanning Tree mode, then the port
mode applies across all VLANs associated with the port. The flat mode instance is specified as the port
instance, even if the port is associated with other VLANs.
To change the port Spanning Tree mode for a VLAN instance regardless of which mode (per-VLAN or
flat) is active for the switch, use the
command sets the mode for port 8/1 for VLAN 10 to forwarding.
-> spantree vlan 10 port 8/1 mode forwarding
To change the port Spanning Tree mode for the flat mode instance, use the
Note that the command is available when the switch is running in either mode (per-VLAN or flat) and an
OmniSwitch AOS Release 8 Network Configuration Guide
spantree cist path-cost command. For example, the following command
spantree msti path-cost
spantree loop-guard
December 2017
Configuring STP Port Parameters
command and specify the MSTI ID for the
Chapter 8, "Configuring Static Link
command. For example, the following
spantree cist mode command.
page 6-38