Using Packet Over SONET (POS) Modules
December 2000 6 - 19
USING THE CLI
To enable STP on a POS port, enter commands such as the following:
BigIron(config)# interface pos 2/1
BigIron(config-if-2/1)# spanning-tree
These commands change the CLI to the configuration level for the POS port, then enable STP on the VLAN.
Syntax: [no] spanning-tree
Enabling or Disabling Fast Uplink Span on the Port
To enable Fast Uplink on a pair of POS ports, use the following CLI method.
USING THE CLI
To configure a group of POS ports for Fast Uplink Span, enter a command such as the following:
BigIron(config)# fast uplink-span pos 2/1 to 2/2
This command configures POS ports 2/1 and 2/2 as a Fast Uplink Span group.
Syntax: [no] fast uplink-span [pos <portnum> [pos <portnum>… | to <portnum>]]
For more information about this feature, see “Configuring Spanning Tree Protocol (STP) and IronSpan” on
page 12-1.
Displaying Spanning Tree Information
To display STP information for a VLAN, enter a command such as the following at any level of the CLI:
BigIron(config)# vlan 10
BigIron(config-vlan-10)# show span
Spanning-tree of port-vlan 1 is disabled.
Global STP Parameters:
VLAN Root Root Root Prio Max He- Ho- Fwd Last Chg Bridge
ID ID Cost Port rity Age llo ld dly Chang cnt Address
Hex sec sec sec sec sec
10 00c800e052a8a520 0 Root 00c8 20 2 2 15 0 2 00e052a8a520
Port STP Parameters:
VLAN Port Prio Path State Fwd Design Design Design
ID Num rity Cost Trans Cost Root Bridge
Hex
10 1/1 80 100 FORWARDING 1 0 00c800e052a8a520 00c800e052a8a520
10 2/1 80 80 FORWARDING 1 0 00c800e052a8a520 00c800e052a8a520
10 2/2 80 80 FORWARDING 1 0 00c800e052a8a520 00c800e052a8a520
This example shows the bridge and port STP information for VLAN 10 in Figure 6.5 on page 6-15. To display
STP information for the entire device, enter the following command at any level of the CLI:
BigIron(config)# show span
This command shows the same information as the command shown above, but for all the VLANs on the device.
For a description of the fields in this display, see “Displaying STP Information for an Entire Device” on page 12-7.
Configuring the POS Ports into a Trunk Group
Use the following CLI method to configure POS ports into a trunk group.
NOTE: You can use a trunk group for Layer 2 POS redundancy and load balancing only on a BigIron or NetIron
running Layer 2 Switch code, not Layer 3 Switch code.