Alcatel-Lucent 7210 SAS-X - Page 383

Virtual Private LAN Services
7210 SAS-X, R6 OS Services Guide Page 383
Values 0 — 65535
path-cost
Syntax path-cost sap-path-cost
no path-cost
Context config>service>vpls>sap>stp
Description This command configures the Spanning Tree Protocol (STP) path cost for the SAP.
The path cost is used by STP to calculate the path cost to the root bridge. The path cost in BPDUs
received on the root port is incremented with the configured path cost for that SAP. When BPDUs are
sent out other egress SAPs , the newly calculated root path cost is used.
STP suggests that the path cost is defined as a function of the link bandwidth. Since SAPs are
controlled by complex queuing dynamics, in the the STP path cost is a purely static configuration.
The no form of this command returns the path cost to the default value.
path-cost — The path cost for the SAP.
Values 1 — 200000000 (1 is the lowest cost)
Default 10
port-num
Syntax [no] port-num virtual-port-number
Context config>service>vpls>sap>stp
config>service>vpls>spoke-sdp>stp
Description This command configures the virtual port number which uniquely identifies a SAP within
configuration bridge protocol data units (BPDUs). The internal representation of a SAP is unique to a
system and has a reference space much bigger than the 12 bits definable in a configuration BPDU.
STP takes the internal representation value of a SAP and identifies it with it’s own virtual port
number that is unique to every other SAP defined on the TLS. The virtual port number is assigned at
the time that the SAP is added to the TLS. Since the order that the SAP was added to the TLS is not
preserved between reboots of the system, the virtual port number may change between restarts of the
STP instance.
The virtual port number cannot be administratively modifed.
priority
Syntax priority bridge-priority
no priority
Context config>service>vpls>stp
config>template>vpls-template>stp