BLADE OS™ Application Guide HP GbE2c Ethernet Blade Switch for c-Class BladeSystem Version 5.1 Advanced Functionality Software

Table Of Contents
BLADE OS 5.1 Application Guide
BMD00113, September 2009 Chapter 6: RSTP and MSTP 123
Port Type and Link Type
Spanning Tree configuration includes the following parameters to support RSTP and MSTP:
edge port
link type.
Although these parameters are configured for Spanning Tree Groups 1-128
(/cfg/l2/stg <x>/port <x>), they only take effect when RSTP/MSTP is turned on.
Edge Port
A port that does not connect to a bridge is called an edge port. Edge ports generally connect to a
server, therefore, ports 1-16 should have edge enabled. Edge ports can start forwarding as soon as
the link is up.
Edge ports do not take part in Spanning Tree, and should not receive BPDUs. If a port with edge
enabled does receive a BPDU, it begins STP processing only if it is connected to a spanning tree
bridge. If it is connected to a host, the edge port ignores BPDUs.
Link Type
The link type determines how the port behaves in regard to Rapid Spanning Tree. The link type
corresponds to the duplex mode of the port, as follows:
p2p: A full-duplex link to another device (point-to-point)
shared: A half-duplex link is a shared segment and can contain more than one device.
auto: The switch dynamically configures the link type.
PVRST+
Per-VLAN Rapid Spanning Tree (PVRST+) allows rapid spanning tree recovery across network
ports and trunks if a link fails on a per VLAN basis. PVRST+ provides RSTP functionality on a
per-VLAN basis. The Spanning Tree functionality is the same as PVST+, and runs RSTP protocol
based on 802.1w. Use the following command to configure PVRST+ on the switch:
/cfg/l2/mrst/mode pvrst