Command Reference Guide

SROS Command Line Interface Reference Guide ATM Sub-Interface Config Command Set
5991-2114 © Copyright 2005 Hewlett-Packard Development Company, L.P. 698
spanning-tree link-type [auto | point-to-point | shared]
Use the spanning-tree link-type command to configure the spanning-tree protocol link type for an
interface. To return to the default value, use the no form of this command.
Syntax Description
auto Link type is determined by the port’s duplex settings.
point-to-point Link type is manually set to point-to-point, regardless of duplex settings.
shared Link type is manually set to shared, regardless of duplex settings.
Default Values
By default, a port is set to auto.
Command Modes
(config-interface)# Interface Configuration Mode
Valid interfaces include: ATM sub-interface, Ethernet, virtual PPP interfaces , and
virtual Frame Relay sub-interfaces
Functional Notes
This command overrides the default link type setting determined by the duplex of the individual port. By
default a port configured for half-duplex is set to shared link type, and a port configured for full-duplex is
set to point-to-point link type. Setting the link type manually overrides the default and forces the port to
use the specified link type. Using the link-type auto command, restore the convention of determining link
type based on duplex settings.
Usage Examples
The following example forces the link type to point-to-point, even if the port is configured to be half-duplex:
(config)#bridge 1 protocol ieee
(config)#interface atm 1.1
(config-atm 1.1)#spanning-tree link-type point-to-point
Technology Review
Rapid transitions are possible in RSTP (rapid spanning-tree protocol) by taking advantage of point-to-point
links (a port is connected to exactly one other bridge) and edge-port connections (a port is not connected
to any additional bridges). Setting the link-type to auto allows the spanning-tree to automatically configure
the link type based on the duplex of the link. Setting the link type to point-to-point allows a half-duplex
link to act as if it were a point-to-point link.