Alcatel-Lucent 7750 SR OS Service Manual page 490

VPLS Service Configuration Commands
The no form of this command returns MST configuration revision to its default value.
Default
0
Parameters
revision-number — Specifies the MSTP region revision number to define the MSTP region.
path-cost
Syntax path-cost sap-path-cost
no path-cost
Context config>service>vpls>sap>stp
config>service>vpls>spoke-sdp>stp
Description
This command configures the Spanning Tree Protocol (STP) path cost for the SAP or spoke SDP.
The SAP or spoke SDP 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 or
spoke SDP. When BPDUs are sent out other egress SAPs or spoke SDPs, the newly calculated root
path cost is used. These are the values used for CIST when running MSTP.
STP suggests that the path cost is defined as a function of the link bandwidth. Since SAPs and spoke
SDPs are controlled by complex queuing dynamics, in the SR-Series 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 or spoke SDP.
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.
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Values
0 — 65535
Values
1 — 65535 (1 is the lowest cost)
Default
10
7750 SR OS Services Guide